ESPA Pain Section

    ESPA Pain Committee

    Per-Arne_LonnqvistVittinghoff 2
    Retired Chair of the ESPA Pain Committee
    Professor Per-Arne Lönnqvist
    Chair of the ESPA Pain Committee
    Acute Postoperative Pain:
    Maria Vittinghoff
    Curriculum Vitae
    Pervin_smallMossetti_pic
    Long-Term and Cancer Pain
    Pervin Bozkurt Sutas
    Curriculum Vitae
    Regional Anaesthesia, General
    Valeria Mossetti
    Curriculum Vitae
     
    Regional Anaesthesia, Ultrasound Guided
    Steve Roberts
     

    ESPA acute pain network

    To further the opportunities to develop various initiatives within the field of acute paediatric pain in Europe the ESPA has recently managed to create a network of people throughout the continent who has a focused interest concerning this important topic. Through its ACORNS representatives ESPA has gathered a network of country representatives that cover the majority of Europe. Among many opportunities the network may be used for activities like:

    • Set up adequately sized multi-centre studies
    • Produce common guidelines
    • Generate a large enough body of interested parties to apply for EU funding of various project
    • Enhance international collaboration in general and promote European exchange of ideas
    • Etc, etc. The sky is the limit!

    Currently 22 pain champions are part of the ESPA APN, representing the following European countries:
    Austria, Belgium, Croatia, Denmark, Estonia, Finland, France, Greece, Hungary, Israel, Italy, Lithuania, The Netherlands, Norway, Poland, Portugal, Serbia, Slovenia, Sweden, Switzerland, Turkey, United Kingdom

    If I have an idea and want to use the ESPA APN, what do I do?

    1. Submit a synopsis of your intended project to the ESPA Pain section chairman. This document should make it clear what the purpose of the project is, how you intend to realize it and the possible results that may come out of the project.
    2. Your proposal will then be reviewed by the ESPA Executive Board and a decision will be made whether the ESPA will allow the use of the ESPA APN or not, and the decision will be communicated to the applicant.
    3. If the proposal is accepted, the ESPA will help circulate the necessary information to the representatives of the ESPA APN.

    This may seem like a slightly bureaucratic process but this is necessary to guarantee a sufficient level of quality and relevance of the initiatives passed through the network as well as to avoid a potential email flood, blocking the country representatives email boxes. However, ESPA will try to be as positive and generous as possible and hope to be able to support the vast majority of requests that will be submitted. If you have any questions with regards to the ESPA APN please do not hesitate to contact the Pain Section chairman by e-mail: per-arne.lonnqvist@ki.se

    Finally, the future impact of this network will entirely rely on how the individual ESPA members chose to use this potentially powerful instrument.

    Starting a Pain Service

    How to start a Paediatric Pain Service?

    If you and your hospital want to take decisive action and start a Paediatric Pain Services we recommend the following recent review by Kost-Byerly and Chalkiadis “Developing a Paediatric Pain Services”. The access through this web-site has been generously granted by Pediatric Anesthesia.

    How to start a paediatric pain service?

    Measurement of pain

    How to measure pain in children- which pain assessment tools to use?

    To successfully address the issue of postoperative pain it is paramount that pain is regularly measured with age-adequate pain assessment tools. The following Clinical Practice Guideline, entitled “The recognition and assessment of acute pain in children”, provides an excellent guide on the state-of-the-art regarding pain assessment in children. This guideline has kindly been made available by the Royal College of Nursing, the Association of Paediatric Anaesthetists of Great Britain and Ireland, The British Pain Society and the Royal College of Paediatrics and Child Health.

    The ESPA would like to underline the importance of choosing age-adequate, well-documented and validated pain scales already from the start. The use of simplified home-made pain scales should be discouraged since the use of such assessment tools will make comparisons with other centres or published literature impossible and will also provide an obstacle when deciding on performing scientific studies. It is much better to implement the use of adequate pain scores already from scratch.

    RCN pain assessment

    Postoperative analgesia

    How to order postoperative analgesia in an effective and safe way?

    Another very important issue in the context of treating postoperative pain is the use of specific pain order sheets. These order sheets should be easy to use as well as provide complete clarity concerning the dosing of the drugs. It has been found valuable to have one specific order sheet for each individual treatment modality (e.g. epidurals, PCA, continuous morphine infusions etc).

    Each hospital may want to create their own order sheets that take into consideration the specific factors associated with their service. However, to use as a template or to get inspired by the Departments of Paediatric Anaethesia at Yorkhill Children’s Hospital in Glasgow and at Alder Hey Children’s Hospital in Liverpool, UK, have kindly volunteered their order sheets as excellent examples of how this can be accomplished.

    • Royal Liverpool Children’s Nhs Trust Pain Service Prescription Sheet
    • Epidural Prescription Chart Royal Hospital for Sick Children, Yorkhill, Glasgow
    • Best practice in the management of epidural analgesia in the hospital setting. Faculty of Pain Medicine
    • Neonatal & Infant Nurse Controlled Analgesia Prescription Chart Royal Hospital for Sick Children, Yorkhill, Glasgow
    • Nurse Controlled Analgesia Prescription Chart Royal Hospital for Sick Children, Yorkhill, Glasgow
    • Intravenous Ketamine Infusion Prescription Royal Hospital for Sick Children, Yorkhill, Glasgow
    • Intravenous Morphine Infusion Prescription Chart Royal Hospital for Sick Children, Yorkhill, Glasgow

     

    Well-functioning Pain Services

    Where can I go to observe how a well-functioning pain service can be provided?

    When thinking about starting a more structured approach to paediatic postoperative pain relief it can obviously be of great help to go and visit centres that already have a well-established pain service. Below are centres that generously accept visitors for this purpose:

    • Royal Hospital for Sick Children,
      Dalnair Street
      GLASGOW  G3 8SJ
      Graham Bell, Consultant Anaesthetist email
    • Sheffield Children’s NHS Foundation Trust,
      Western Bank,
      SHEFFIELD  S10 2TH
      Rebecca Reaney, Clinical Nurse Specialist
    • Alder Hey Children’s NHS Foundation Trust,
      LIVERPOOL  L12 2AP
      Jennie Craske, Clinical Nurse Specialist
    • Astrid Lindgrens Children’s Hospital/Karolinska University Hospital-Solna,
      171 76 Stockholm,
      Sweden
      Stefan Lundeberg, MD PhD, Consultant Anaesthetist

    US Regional Anaesthesia

    Introduction

    Dear Colleague,
    Bonjour , Welcome, Wilkommen ….. to the Ultrasound Regional Anaesthesia section of the ESPA Website.

    Regional anaesthesia is such an important and beneficial technique it should be considered for all appropriate cases, balancing the advantages against the potential risks. However, it can only be utilised by those with the correct anatomical knowledge, suitable training, equipment and assistance. We aim to provide paediatric anaesthetists with an up to date concise guide to ultrasound guided regional anaesthetic techniques in children.

    The format for each block will cover all aspects from indication through to complications of each technique. At the end of each section you will be able to access a self assessment section. We will not be covering every possible way of performing these blocks.

    We are keen for feedback so that we can improve the website, so please email us your suggestions to info@euroespa.com

    Best wishes,

    Steve Roberts, Chair UltraSound for Regional Anaesthesia Committee

    Disclaimer: The ESPA web site is intended for use by medical professionals, specifically those who perform invasive regional anaesthetic procedures. ESPA and those associated with it make no warranties as to the correctness, safety or appropriateness of any treatment, medications, dosage, techniques or any other aspects of medical practice or patient care and safety.  Nothing in this site should be interpreted to imply that anything but your clinical judgement is appropriate for making safe medical decisions and implementing therapies for your patients.

    Direct Epidural

    Author: Dr Wolfgang Klug

    Content

    An epidural anaesthesia (single shot technique, catheter technique) provides intraoperative and postoperative analgesia for thoracal, abdominal and lower limb surgery. This type of anaesthesia can be performed regardless of age and weight. Nevertheless, in small infants (weight < 1000g) a risk/benefit assessment should be considered. (skin <-> dura < 3mm resulting in a higher risk of perforation the dura mater). In that circumstances maybe a caudal blockade should be considered.

    Indications

    Specifically, it may be useful for the following operations:

    Thoracotomy/thoracoscopic interventions, e.g.

    • Pleural decortikation
    • Resection of a tumor, aspergilloma, lung sequestriation, emphysem bullae
    • Congenital cystic adenomatoid malformation of the lungs (CCAM)
    • Esophagial atresia
    • Funnel chest operation (NUSS)

    Laparotomy/laparoscopic interventions, e.g.

    • Wilms tumor
    • NEC
    • Hernia of the diaphragm

    And also lower limb surgery

    Operation Puncture siteNecessary analgesia
    ThoracotomyTh 6-7Th 2-8
    Thoraco-abdominal surgeryTh 7-8 / Th 8-9Th 4-12
    Upper abdominal surgeryTh 8-9 / Th 9-10Th 6-12
    Lower abdominal surgeryTh 10-11 / Th 11-12Th 8- lumbal 2
    Lower limb surgeryLumbal 3-4Th 12- sacral 1

    Specific contraindications

    • Patients/parents refusal
    • Coagulation disorder (Neonates do have an abnormal coagulation)
    • Infections on the puncture site
    • Neurological diseases e.g. high intracranial pressure
    • Immune compromised children

    Anatomy

    • The epidural space extends from the Foramen magnum to the Sacrococcygeum ligament between the dura mater spinalis and the outer part of the dura (periost)
    • The dorsal boundary is formed by the Lig. Flavum, lateral the epidural space has a connection to the paravertebral space through the intervertebral foramina
    • The ventral boundary is formed by the rear ribbon of the vertebral bodies
    • The epidural space has different withs: lumbal 5-6mm, thoracal 3-5mm, cervical approx.. 3mm in adults. In children it can be assumed, that the skin – epidural distance is 1mm per kg BW. (e.g. 3000g – 3mm)

    Structures inside the epidural space

    The epidural space contains adipose tissue (fat), connective tissue and numerous vessels (arteries, venes and lymphatic vessels) and the roots of the spinal nerves.

    Material

    Tuohy needlesizelengthcatheterBW
    20G5mm24G< 5kg
    19G5mm23G5-20kg
    18G5mm20G> 20kg

    LA

    RopivacaineSingle shot/punctureCatheter
    Lumbal0.5ml/kg Ropivacaine 0.37%1/3-1/2 of the initial dosage as a bolus every 60 min.
    Thoracal0.75ml/kg Ropivacaine 0.37%
    PostoperativeRopivacaine 0.2% – 0.25-0.4ml*kg h-1 switch to Ropivacaine 0.1% as soon as possible

    Technique

    • This type of anaesthesia has become very save in recent time, in particular when using an ultrasound for puncture. (Even in very small infants).
    • Place the patient in a left lateral position with hips and knees flexed.
    • The US machine should be positioned on the opposite side of the trolley, i.e. in direct line sight.
    • After skin disinfection and draping the puncture site, the assessment of the patients epidural anatomy should be performed by US, in particular the skin – epidural space distance. To know the skin – epidural distance prior to puncture is very helpful and may reduce the risk of an accidental dura perforation especially when using LOR technique.
    • The use of a XXX mm linear probe (even in small infants) allows more intervertebral levels to be viewed, thereby the spread of the LA and the position of the catheter can be monitored more suffiently.
    • The probe should be placed in Paravetrebral Longitudinal position close to the spinal processi. The probe should be slightly moved to an angle about 70-80 degrees (to skin area) until the epidural space (dura mater) gets visible. Fig.1
    • Measurement of the skin epidural distance Fig.2
    • Perform the puncture as you normally would.
    • When you have a LOR, verify the LA spread in the right compartment via US. V.1
    • V.1: Spread of the LA into the epidural space. Anterior movement of the dura mater can be identified.

    • Inert the catheter and fix it.
    • At least verify the right position of the catheter by injecting more LA. Fig.3
    • Fix the catheter

    Fig. 1
    epid.an.fig1

    Fig.1: <= Dura mater, * Epidural space, + Spinal cord

    Fig. 2
    epid.an.fig2

    Fig.2: <= Dura mater, Distance skin – epidural space

    Fig. 3
    epid.an.fig3

    Fig.3: => Tip of the catheter, * Epidural catheter

    Specific complications

    • Accidental perforation of the dura – blood patch
    • Epidural hematoma – MRT and surgery
    • Infection – removal of the catheter
    • Malfunction of anaesthesia – pull back the catheter and give one bolus again. Otherwise remove the catheter
    • Only one side anaesthesia – pull back the catheter 1cm, give one more bolus. Otherwise removal.
    • Perioperative coagulation disorder – do not remove the catheter until the coagulation has normal values

    V.2: Video-Tutorial of performing an epidural blockade

    Caudal block

    Dr Steve Roberts

    Content

    Indications
    Specific contraindications
    Anatomy
    Technique
    Volume of LA
    Specific complications
    Self-Assessment
    Bibliography

    Indications

    A caudal block provides intraoperative and postoperative analgesia for infraumbilical and lower limb surgery.

    In children older than 2 years of age cephalad spread is increasingly unreliable; in these circumstances alternative techniques e.g. truncal block or direct lumbar/thoracic epidural should be considered.

    Specifically, it may be useful for the following operations:

    • Circumcision
    • Hypospadias
    • Lower abdominal surgery e.g. ilioinguinal hernia repair
    • Lower limb surgery e.g. club foot correction

    Caudal catheters will be discussed in a separate section.

    Specific contraindications

    Spinal dysraphism (not cutaneous stigmata of spinal dysraphism, US allows screening of the spine).

    Anatomy

    • The caudal epidural space is the lowest section of the epidural space and is entered via the sacral hiatus.
    • The non-fusion of the laminae of S5 and/or S4 creates the sacral hiatus.
    • The sacral canal is a continuation of the lumbar spinal canal, which terminates at the sacral hiatus. 
    • The dural sac finishes at the L2 level (with a range of T10-L3) in term infants, and in preterm infants at L4.
    • US does not pass through bone.
    • With increasing age the spine becomes increasingly ossified, so diminishing the size of the echo windows (the view between the intervertebral spinous processes and laminae).
    • The more cephalad the smaller the echo windows are compared to the ossified sections of the spine; particularly as the spinous processes become more angulated.  

    ECHO window : Ossification

    Caudal2:1
    Lumbar1:1
    Thoracic1:2
    • In neonates and infants a midline sagittal probe position provides a good view; but with increasing age and lumbar/thoracic spine scanning a paramedian position increases the echo window size.
    • The dural sac is hyperechoic (white) and its’ termination is readily identified. Within the dural sac the CSF is anechoic (black), the cauda equina is seen within as multiple hyperechoic lines.
    • The thickest line within the cauda equina is the filum terminale, it should not be more than 2mm thick. Greater than 2 mm is an indication of spinal cord tethering.
    • A tethered cord also has the following features: pulseless, the cord is positioned more posteriorly within the spinal canal.

     

    Fig 1. Ultrasound Probe in Midline Transverse position over the coccyx.

    Fig 2. Ultrasound Probe in Midline Transverse position over the coccyx.

    Fig 3. Ultrasound Probe in Midline Transverse position moved cephalad along sacrum.

    C – sacral cornu, white asterisk sacrococcygeal membrane.

    Fig 4. Ultrasound Probe in Midline Longitudinal position over sacrum.

    Fig 5. Ultrasound Probe in Midline Longitudinal Plane over sacrum.  D – dura, SCM –   sacrococcygeal membrane

    Fig 6. Ultrasound Probe in Midline Longitudinal position over the sacrum. CE = cauda equina. CSF = ceerbrospinal fluid (anechoic), PD = posterior dura (hyperechoic), SP = spinous process.

    Fig 7. Ultrasound Probe in Midline Transverse position over the sacrum. CE = cauda equina. CSF = ceerbrospinal fluid (anechoic), PD = posterior dura (hyperechoic), SP = spinous process.

    Technique
    • This block is easily performed without US, but assessment of correct cannula placement has remained an issue despite various tests being introduced. The serious complications of intravascular and intrathecal injection remain a concern.
    • Where the block is difficult (in the author’s opinion this is defined as being unable to place the cannula within 2 attempts) US can be used to guide the cannula/needle. An in plane needling technique is employed with the probe in the midline sagittal plane.
    • Place the patient in the standard left lateral position with hips and knees flexed.
    • The US machine should be positioned on the opposite side of the trolley to that where the operator is stood, i.e. in direct line of sight.
    • Prior to performing the caudal a ‘Mapping’ or ‘Scout’ scan is performed to assess the position of the dural sac in relation to the sacrococcygeal membrane. The angle of needle/cannula insertion can be observed. See Figs 1-7.
    • A large foot print linear probe (35mm) is ideal as it allows more intervertebral levels to be viewed, this is particularly useful when monitoring the spread of the LA or the migration of a caudal catheter.
    • The probe should be placed in a transverse plane over the sacral hiatus first, then rotate the probe into a midline sagittal plane (the left of the screen should be cephalad).
    • Perform the caudal as you normally would.
    • The author’s preferred technique is to insert the cannula at the very apex of the sacral hiatus perpendicular to the skin. Once resistance is felt re-angle the needle to approx. 30 degrees and insert a further 5mm, then slide the cannula off the needle (it should slide off easily).
    • Open the cannula to air and observe for blood or CSF.
    • Then aspirate with a 2ml syringe.
    • If the fluid is blood stained and not obviously in a vessel leave the cannula in position and wait to see what happens with the saline test bolus.
    • Position the probe in the midline sagittal plane again, the cannula/needle may be visible. See Fig 8 below.

     

    Fig 8. Ultrasound probe in Midline Longitudinal Plane, needle observed entering caudal space from right top hand corner of screen.

     

    • Inject <0.1ml/kg of normal saline (this avoids wasting valuable LA, and is harmless if injected intravasculalry). See Fig 9 and 10 below. Where the posterior dura can be observed moving anteriorly as the epidural space is expanded.

    Fig. 9 Patient in left lateral, cannula in situ with 2 ml syringe of saline attached. Note use of large footprint probe to give greater view of spine and observe for test injection.

    Fig 10. Ultrasound probe in Midline Longitudinal position, saline test bolus seen as anechoic area displacing the posterior dura anteriorly.

    • Correct cannula position will see the test bolus of saline expand the epidural space, displacing the posterior dura anteriorly.
    • If the saline test bolus is not seen then either the cannula/needle is in a vessel or the probe is not positioned correctly (check your probe position).
    • After a positive saline test bolus attach your LA.
    • The LA spread can be monitored to ensure it has spread high enough for the intended surgery. See Fig 11,12 and Video
    • In neonates the probe can stay in the midline sagittal position, in older children it will be necessary to use the paramedian sagittal views (left and right) as the echo windows are greatest between the laminae. The probe moves synchronously cephalad as the LA spreads higher.
    • Aspirate repeatedly during the block.
    • Ensure the syringe is tightly attached to the cannula/needle as it is easy to be distracted by the US images and for the cannula to become displaced by a lack of attention.

    VIDEO: Ultrasound of showing…

    Fig 11. Ultrasound Probe in Midline Longitudinal position over the lumbar spine. White * indicates local anaesthetic seen as anechoic area in posterior epidural space. CM = conus medullaris (anechoic with hyperechoic outline) with hyperechoic linear pattern of cauda equine attached.

    Fig 12. Ultrasound Probe in Midline Transverse position over the lumbar spine. White * indicates local anaesthetic seen as anechoic area in posterior epidural space.

     

    Volume of LA
    • The volume injected must not be greater than the maximum possible dose. Spread of local anaesthetic within the epidural space should be monitored with US to ensure the appropriate level is reached for the intended operation.
    • For neonates 0.125% levobupivacaine is effective and allows a greater volume to be injected should a mid thoracic level be desired (and an alternative technique e.g. direct thoracic epidural or caudal catheter is considered less appropriate).
    Specific complications
    • Intravascular injection.
    • Spinal injection.
    • Failure or inadequate block.
    Top tips
    • Use US to screen patients with cutaneous markers of spinal dysraphism.
    • Use a saline test dose (safe if injected intravascularly and does not waste precious LA).
    • If saline test dose not visible are you scanning in the wrong area or is the cannula intravascular?
    • In neonates use 0.125% levobupivacaine as this is equally effective and minimises dosage.
    Bibliography

    http://www.sonographycme.com/cfm/lectures/lect001001.cfm

    Park JH, Koo BN, Kim JY, Cho JE, Kim WO, Kil HK: Determination of the optimal angle for needle insertion during caudal block in children using ultrasound imaging. Anaesthesia 2006; 61: 946-9.

    Roberts S A, Guruswamy V, Galvez I. Caudal injectate can be reliably imaged using portable ultrasound–a preliminary study.  Paediatr Anaesth 2005; 15: 948-952.

    Lundblad M, Lonnqvist PA, Eksborg S, Marhofer P. Segmental distribution of cuadal anesthesia (1.5 ml kg−1) in neonates, infants and toddlers as assessed by ultrasonography. Paediatr Anaesth 2011;21:121–7.

    General considerations

    Steve Roberts

    The following considerations should be applied to the majority of blocks described hereafter.
    When performing these techniques it should always be remembered that a strong knowledge of anatomy is essential, that you need to be appropriately trained, and that the correct equipment and assistance must be available. Ultrasound is operator dependent.

    Pre-operative
    • Prior to meeting the patient, understand the extent of the surgery being planned and the consequent length of analgesia required.
    • Generally the more peripheral a block is – the better the risk-benefit balance. And thus more acceptable to the patient and parents/carers.
    • If prolonged analgesia is required due to the amount of surgical trauma, or to facilitate physiotherapy then a catheter technique should be considered;
    • If you are considering a catheter technique give thought to where the patient will be nursed, often catheter techniques can only be nursed on specific wards. Don’t offer something that cannot be delivered.
    History
    • In particular looking to identify potential contraindications to regional anaesthesia (local anaesthetic allergy, anticoagulation).
    • Identify pathology that may make a technique difficult or impossible e.g. spina bifida or scoliosis.
    • Discuss patient’s experiences with previous regional anaesthetic techniques.
    • A Pain history is important because some patients e.g. those with developmental delay may find it difficult to express their pain. How well do they cope with pain? How do they show their discomfort? A chronic pain history should highlight the possibilities of difficulties with post operative pain management; a catheter technique may be beneficial in these patients.
    • Drug history: analgesics, anticoagulants, baclofen.  Patients on baclofen undergoing orthopaedic procedures may be at increased risk of muscle spasm post operatively, consider a catheter technique.
    Examination
    • If possible check the proposed injection site.
    • If feasible assess and document neurology of patients with known neuromuscular conditions.
    • Make a note of patient’s weight so maximum local anaesthetic dose can be calculated.
    Consultation
    • At all times during the consultation a realistic description of success and post op course should be given. This should include what will happen should the original planned analgesia fail. Manage expectations.
    • Discuss with patient and carers options for analgesia covering both benefits and risks.
    • If possible explain to patient how their limb will feel post operatively, ‘like pins and needles when you fall asleep on your arm’. Children can become quite anxious in recovery as a consequence of the paraesthesiae.
    • In older children having minor surgery the operation may be done awake; have EMLA applied to the block injection site (you may wish to scan the patient on the ward prior to this). If a parent/carer is going to attend ensure they know what their job is in the anaesthetic room i.e. distracting their child during the proceedings. Ensure a nurse will be attending the procedure to support both the patient and the parent/carer.
    Anaesthetic Room
    • Full and appropriate monitoring is assumed throughout the website.
    • Intravenous access and airway both secured.
    • If prophylactic antibiotics indicated for surgery then administer it pre-block.
    • Position patient safely in block position.
    • Assess surface anatomy.
    • Position your ultrasound machine such that you can clearly see it without turning your head.

    ERGONOMICS IS IMPORTANT.
    Fig. Neonatal TAP block, operator, probe, patient and machine in alignment makes needling easier.

    • Choose an appropriate probe.
      Note that the majority of US probes are broadband arrays i.e. the frequency is chosen from within a given range.
      A typical linear probe has a 10-5MHz frequency range or better, as such they are suitable for the majority of blocks in children. More modern probes will have higher frequencies of up to 15MHz.
      The curvilinear probes are of lower frequency and are suited to deep needle placement e.g. a lumbar plexus or epidural scan in an adult.
      The second feature to consider when choosing a probe is the size of its footprint. This will depend on which block is being used and the size of the patient. Generally a hockey stick probe with a 25mm or less footprint is suited for blocks in children under 10kg or where access is limited e.g. the neck.
    • For single shot blocks – Wash hands and wear sterile gloves. Cover the probe directly with a transparent occlusive dressing such as an IV3000; you will need to pull the dressing taught over the probe so as not to allow any air to become trapped.

    • For continuous catheter techniques – all central techniques require a full aseptic technique (mask, gown, gloves); it is probably also advisable for paravertebral (due to proximity to epidural space) and psoas blocks (a deep block, also bacteraemia has been reported post block). For more peripheral blocks it is debatable whether a gown is necessary. The probe should be placed in a sheath for all catheter techniques.

    • Prep and drape the patient. This can be allowed to dry whilst you prepare the rest of the equipment. Ensure a large enough area of the patient is prepped and visible so that the length of the nerve can be scanned if necessary.
    • For peripheral nerve blocks choose an appropriately long 18G regional anaesthetic needle. This depends on the expected depth of the target nerve (patient age and BMI), and whether an in plane or out of plane needling technique is deployed. The former entails inserting the needle 2-3 times further into the patient.
      You should have 2 lengths available to your department, a 40 or 50mm and an 80-100mm length needle. This should cover most eventualities. All neonatal blocks can be performed with a 40-50mm needle; do not use a longer needle than necessary.
    • Ensure all the kit is flushed through, so that no air is present. If a catheter is used ensure this is patent prior to insertion.
      If concerned about the amount of local anaesthetic available due to the small size of patient use saline for the flush.
    • Select which % local anaesthetic. Do not draw up more local anaesthetic than the maximum safe dose by weight.
      Usually 0.25% levobupivacaine, ropivacaine or bupivacaine is used.
      Use 0.125% levobupivacaine if there is concern regarding compartment syndrome or in neonates where there is concern regarding local anaesthetic toxicity. 
      Use 0.5% levobupivacaine, ropivacaine or bupivacaine for orthopaedic surgery where there is a high risk of muscle spasm post op e.g. multiple lower limb tendon transfers in cerebral palsy patient on baclofen.
    • Now set up the ultrasound machine.
      Choose the highest frequency appropriate for estimated depth of the block.
      Some machines allow you to opt for a ‘nerve’ setting thus optimising the image.
      Select a depth greater than you expect to find the target nerve.
      Ensure the gain is optimised. This is done by ensuring any vessels are black i.e. anechoic, and that the screen as a whole is a uniform grey.
    • It is useful for the needle to have an extension to connect it to the syringe.
    • Orientate probe and image; most manufacturers have a tag on the screen to indicate which side of the probe is which. Alternatively touch one end of the probe
    • Use adequate US gel to provide an air free interface
    • A mapping or scout scan is performed to assess the anatomy, whilst scanning part of your hand should maintain contact with the patient to prevent the probe sliding off.
    • To ensure correct orientation start scanning deeper than the expected target depth, then as the relevant bony and vascular landmarks are recognised decrease the depth until the target nerve of fascial layer is positioned in the middle of the screen.
    • For in plane techniques the target should be moved to the side of the screen opposite to the needle entry point. This allows more time for the needle to be guided towards the target. Generally the needle should be inserted in as shallow a trajectory as is practically possible as this creates the best needle image. The needle should initially be aimed at the 6 o’clock position i.e. behind the nerve. After aspiration local anaesthetic is injected, if the nerve does not look to be surrounded then it may be necessary to withdraw the needle and aim at the 12 O’clock position i.e.
    • For out of plane techniques the target should be in the middle of the screen, the needle is aimed at the 3 and/or 9 O’clock position i.e. either side of the nerve.
    • If you lose the needle, immediately stop and check your probe and needle orientation. Use your probe to find the needle do NOT try to move your needle into the ultrasound beam.
    • Some experts use PNS and US together. Whilst there is nothing inherently wrong with this beware of not identifying correct local anaesthetic spread and accepting a good motor response alone.
    • Always aspirate prior to injection. In small children (<10kg) especially when learning use saline instead of local anaesthetic for you initial injection as this stops local anaesthetic being wasted due to poor needle position.
    • The local anaesthetic should spread around the nerve – the ‘Doughnut sign’.
    Intra operative management of block
    • Ensure systemic analgesia given for procedures where the block does not cover visceral pain e.g. a rectus sheath block for pyloromyotomy.
    • Observe changes in HR, BP and RR to provide information to assess any deficiencies in the regional anaesthetic technique employed.
    • Consider avoiding anaesthetic agents that may obscure assessment of block success i.e. nitrous oxide and opiates. This is especially true when managing children with special needs as they can be very hard to assess in recovery.
    • Consider systemic analgesic adjuvants e.g. magnesium is useful to give to cerebral palsy children under going reconstructive lower limb surgery
      PACU / FIRST STAGE RECOVERY
    • It can be difficult to distinguish pain from emergence delirium or in fact just the displeasure of the paraesthesia. The help of an experienced recovery nurse and parent aids diagnosis.
    • If there are doubts regarding analgesia consider giving a small fast acting opiate e.g. 0.25mcg/kg of fentanyl or 0.2-0.3mg.kg ketamine. If the block is effective the child will immediately settle.
    • If doubts remain regarding the efficacy of your block it may be prudent (operation dependent) to prescribe a NCA/PCA just in case.
    • All patients should be written up for alternative systemic analgesics as rescue analgesia.
    COMMON ERRORS
    • Failure to recognize maldistribution of LA, particularly when using PNS
    • Orientation, every so often check your orientation, particularly during catherer insertions where the probe may have been put down and picked up again.
    • Poor choice of needle-insertion site and angle
    • Over insertion of needle due to poor needle visualisation, NEVER advance your needle if you don’t know where the tip is
      Top Tips

     

    • Generally it is best to teach yourself to scan with your non dominant hand
    • Practice scanning techniques on yourselves and staff FIRST
    • Practice needling techniques on phantoms FIRST
    • Start with simple and familiar blocks in teenagers e.g. fore arm nerves or femoral nerve blocks
    • If you can’t find the needle tip move the probe to find it – don’t move the needle.
    • Consider using a Peripheral Nerve Stimulator until you master US
    • Use the highest frequency available for the depth of target in tissues
    • For children less than 10kg consider using saline to assess initial spread and as such needle position. This avoids wasting limited local anaesthetic in the wrong place.

     

    • REMEMBER Ultrasound Guided Regional Anaesthesia is only as good as the operator

    Head and neck

    usra_10

    Superficial cervical plexusblock

    Superficial (and Intermediate) Cervical Plexus Block

    Dr David Stoeter

    Content

    Indications

    Specific Contraindications

    Anatomy

    Technique

    Volume of LA

    Specific complications

    Bibliography

    Please view the full article HERE.

    Indications:

    –Lymph node excision (within the anterior and posterior triangles of the neck)

    –Clavicular surgery or fractures (may require intermediate cervical plexus block and  its combination with interscalene block, see below)

    –Central Venous Catheters: Renal replacement therapy central venous catheters, tunnelled  central venous catheters and portacaths inserted into the subclavian or jugular veins (may require combination with ‘Pecs 1’ block for component of pain below the clavicle)

    –Tracheostomy (see below discussion on safety profile of performing bilateral blocks and risks of respiratory distress due to phrenic nerve or recurrent largyngeal nerve block)

    -More commonly in adults: thyroid (again, bilateral) and carotid surgery

    Upper limb

    usra_11

    Supraclavicular

    Author: Dr. Nuria Masip


    1. Indications

    Supraclavicular block provides intraoperative and postoperative analgesia for all procedures on the upper extremity not involving the shoulder (1).

    2. Specific contraindications

    • Local infection
    • Supraclavicular block should not be done bilaterally because of the potential respiratory problems originating from complications such as phrenic nerve block or pneumothorax (2).

    3. Anatomy


    The Brachial Plexus (3) is formed from the anterior primary rami of C5, C6, C7, C8 and T1. These nerve roots emerge from the intervertebral foramina between the anterior scalene and middle scalene muscles, being enclosed by a fascial sheath from these muscles.

    The nerve roots unite to form trunks:

    • C5 and C6 unite to form the superior trunk
    • C7 forms the middle trunk
    • C8 andT1 roots unite to form the lower trunk.

    These trunks continue distally towards the axilla, sandwiched between the anterior scalene muscle (anteromedially) and the middle scalene muscle (posterolaterally), running parallel and supero-posterior to the subclavian artery, which is also enclosed by the fascial sheath.

    As these trunks pass posterior to the clavicle, each trunk bifurcates into anterior and posterior divisions, which will reunite in the three cords of the brachial plexus:

    • The anterior divisions of the upper and middle trunk unite to form the lateral cord
    • The anterior division of the lower trunk forms the medial cord
    • The posterior divisions of the three trunks unite to form the posterior cord.

    These cords are named based on their relation to the axillary artery and divide into the nerves that supply the upper limb.

    • Lateral cord – Lateral root of median nerve, Musculocutaneous nerve
    • Medial cord – Medial root of median nerve, Ulnar nerve, Medial cutaneous nerves of arm and forearm
    • Posterior Cord – Axillary and Radial nerves

    4. Technique

    • Position the patient in a semi-sitting position (this reduces the venous pressure in the neck) and turn patient’s head slightly away from the block site. In very small patients, shoulders should be elevated.
    • Use a high frequency linear probe (> 10 MHz).
    • A small footprint 25 mm linear probe.is desirable with smaller patients <15kg.
    • The ultrasound machine is positioned on the far side of the patient, with the operator stood on the side to be blocked. The dominant hand manipulates the needle (which enters from lateral to medial).
    • Using the non-dominant hand place the probe over the supraclavicular fossa, parallel to the clavicle, looking down into the chest. See Fig.1

    1
    Fig 1.
    Patient and probe position, note the head ring and a shoulder support, this allows better needle access.

    • The probe should be angled/tilted till an optimal image is obtained where we can clearly identify these four structures: the subclavian artery, the first rib, the pleura and the brachial plexus.
    • The first structure to locate is the round pulsating hypoechoic subclavian artery (A), lying on top of the hyperechoic first rib (R). Use Doppler to assess for vessels. See Fig. 2.

    2
    Fig. 2.
    Bidirectional Doppler used here to highlight the subclavian artery.

    • The subclavian vein (V) is found more medially to the artery. The anterior scalene muscle inserts onto the first rib between these two vessels (A and V), but occasionally there are anatomical variations (4) where both vessels are together between the insertions of both the scalene muscles (anterior and middle ones).
    • Quite often the dorsal scapular artery is seen coming off the subclavian artery and passing through the brachial plexus. See Fig. 9.
    • A linear hyperechoic structure immediately deep and lateral to the A is the first rib with its bony shadow. However, in small children the cortical layer of ribs is thin enough that you can see both layers of the rib cortex and visualise lower down another bright line: the parietal and visceral pleura interface. See Fig. 3.
    • Identify also another linear hyperechoic structure, which will be the pleura. Note the air artefact (the “comet tail” sign) and the pleura sliding movement during respiration.

    3
    Fig. 3.
    Sonoanatomy of infant supraclavicular region. A – Subclavian artery. B – brachial plexus, P – pleura, R – first rib, V – subclavian vein

    • A mirror or reverberation artefact of the Subclavian Artery often occurs, mimicking a second Subclavian Artery beneath the rib. See Fig.

    4
    Fig.4
    . Mirror artefact of subclavian artery

    • Lateral and above the artery sit a bundle of round hypoechoic circles (“bunch of grapes” or “cluster of bubbles”) – the brachial plexus, at this level, the plexus will be configured as trunks and/or divisions.
    • It may be possible to identify the hypoechoic nodules surrounded by a hyper-reflective fascial sheath.
    • When the plexus is difficult to identify, it can be useful to follow it proximally in the neck (in the interscalene space).

    In plane technique:

    • VIDEO LINK
    • Introduce the needle from the lateral side of the probe advancing medially. See Fig. 5.

    5
    Fig. 5.
    Needle introduced from posterolateral to anteromedial, bevel up.

    • Position the needle within the sheath, often a “pop” is felt as the needle passes through the brachial plexus sheath.
    • Local anaesthetic (LA) should spread around the hypoechoic circles causing hydro dissection of the planes. (5) See 6. & 7.

    6
    Fig. 6.
    Initial injection of LA, note proximity to subclavian artery. Excellent needle control is required to safely perform this technique.

    7
    Fig. 7.
    Increasing spread of LAj

    • It may sometimes be necessary to reposition the needle to ensure an adequate distribution of the LA (the entire plexus is surrounded by LA). See Fig. 8.

    8
    Fig. 8.
    Needle withdrawn and re –directed over the superior aspect of the brachial plexus, LA deposited to surround brachial plexus.

    • Never inject against high resistance, this may be a sign of an intrafascicular injection.
    • Although, there will be slightly more resistance when initially injecting within the sheath than normally felt outside the sheath, but the resistance will ease quickly. The LA will then be distributed cephalad and caudally within the sheath.
    • If anaesthesia is intended for the distal upper limb, aim to spread LA in the corner bordered by the subclavian artery medially, the first rib inferiorly, and the divisions of the brachial plexus superior laterally (“the corner pocket”, and the ulnar nerve in this position would be “the 8-ball”) (6) (7).
    • The safety of positioning the needle tip within the brachial fascia sheath and spreading LA among the neural clusters is controversial:
      • In a 2009 observational study, Bigeleisen et al. (8) opined that positioning the needle tip inside a cluster equated to intraneural placement (and intraneural LA injection).
    • In contrast, in a further publication, Franco (9) argued “penetrating the prevertebral fascia during an interscalene or supraclavicular block, for example, does not constitute intraneural injection as has been erroneously postulated, unless the individual epineurium of the individual nerve structures (roots, trunks, or divisions) is penetrated.”
      • Regardless of whether LA is deposited inside the neural cluster amounts to true intraneural injection or not (10) (11), it seems to be safe and therefore is the approach described here.

    5.    Volume of LA

    Generally 0.3-0.5ml/kg is used, but doses as low as 0.1–0.2 ml/kg of 0.25% Levobupivacaine can be used successfully.

    6.    Potential complications

    • Pneumothorax (12, 13) – careful when positioning needle in “the corner pocket”.
    • Phrenic nerve block (~50%, due to proximal spread of the LA within the sheath).
    • Horner’s syndrome (~1%)(14) (due to proximal spread of the LA within the sheath and blockage of sympathetic afferents).
    • Unintended vascular punctures (~0.4%)(14)
    • Intravascular injection with LA toxicity.
    • Neurological injury (15) (rare) – most are temporary rather than permanent.

    7.    Top tips

    Always use US in children when performing this block.

    Before performing the block, four structures must have been identified: the subclavian artery, the two linear hyperechoic structures (first rib and pleura) and the brachial plexus, all these structures should be kept in view.

    Hypoechoic vessels may be seen among the brachial plexus nerves (also round hypoechoic structures). Because they have similar appearance, it is important to differentiate them (colour Doppler MUST be used) (16). See Fig. 9.

    9
    Fig. 9.
    Doppler highlighting subclavian artery with dorsal scapular artery passing posteriorly through brachial plexus.

    When the plexus is difficult to identify, it can be useful to scan higher in the neck finding the nerve roots sandwiched by the scalene muscles and follow them down.

    If the block is performed for hand surgery, it is important to spread the local anaesthetic near the inferior trunk, this is situated in the most dangerous area (risk of pneumothorax) where the artery meets then rib/pleura (“the corner pocket”).

    When placing catheters an in plane technique can be used, by inserting the needle from a more posterior position the catheter can be self-tunnelled. When using a needle with a Huber tip it may be useful to aim the bevel caudad and lateral with a view to threading the catheter in the direction the brachial plexus is travelling. See Fig. 10.

    10
    Fig. 10.
    Longitudinal view of peripheral nerve catheter positioned beneath brachial plexus.

    8.    Bibliography

    1. Marhofer P, Lonnqvist PA. The use of ultrasound-guided regional anaesthetic techniques in neonates and young infants. Acta Anaesthesiol Scand. 2014;58:1049-1060.
    2. Gelpi B, Telang PR, Samuelson CG, Hamilton CS, Billiodeaux S. Bilateral ultrasound-guided supraclavicular block in a patient with severe electrocution injuries of the upper extremities. J La State Med Soc. 2014;166:60-62.
    3. Standring S. (ed.) 2008. Gray’s Anatomy: The Anatomical Basis of Clinical Practice. 40th Ed. Churchill Livingstone, Philadelphia. p 1–1576.
    4. Muhly WT, Orebaugh SL. Sonoanatomy of the vasculature at the supraclavicular and interscalene regions relevant for brachial plexus block. Acta Anaesthesiol Scand. 2011;55:1247-1253.
    5. Techasuk W, Gonzalez AP, Bernucci F, Cupido T, Finlayson RJ, Tran DQ. A randomized comparison between double-injection and targeted intracluster-injection ultrasound-guided supraclavicular brachial plexus block. Anesth Analg. 2014;118:1363-1369.
    6. Soares LG, Brull R, Lai J, Chan VW. Eight ball, corner pocket: the optimal needle position for ultrasound-guided supraclavicular block.[letter]. Reg Anesth Pain Med 2007;32(1):94-95.
    7. De Jose Maria B, Banus E, Navarro Egea M, Serrano S, Perello M, Mabrok M. Ultrasound-guided supraclavicular vs infraclavicular brachial plexus blocks in children. Paediatr Anaesth. 2008;18:838-844.
    8. Bigeleisen PE, Moayeri N, Groen GJ. Extraneural versus intraneural stimulation thresholds during ultrasound-guided supraclavicular block. Anesthesiology. 2009;110:1235-1243.
    9. Franco CD. Connective tissues associated with peripheral nerves. Reg Anesth Pain Med. 2012;37:363-365.
    10. Morfey D, Brull R. Ultrasound-guided supraclavicular block: What is intraneural? Anesthesiology. 2010;112:250-1; author reply 251.
    11. Jeng CL, Rosenblatt MA. Intraneural injections and regional anesthesia: the known and the unknown. Minerva Anestesiol. 2011;77:54-58.
    12. Abell DJ, Barrington MJ. Pneumothorax after ultrasound-guided supraclavicular block: presenting features, risk, and related training. Reg Anesth Pain Med. 2014;39:164-167.
    13. Kakazu C, Tokhner V, Li J, Ou R, Simmons E. In the new era of ultrasound guidance: is pneumothorax from supraclavicular block a rare complication of the past?[letter]. Br J Anaesth 2014;113(1):190-191.
    14. Hanumanthaiah D, Vaidiyanathan S, Garstka M, Szucs S, Iohom G. Ultrasound guided supraclavicular block. Med Ultrason. 2013;15:224-229.
    15. Liu SS, YaDeau JT, Shaw PM, Wilfred S, Shetty T, Gordon M. Incidence of unintentional intraneural injection and postoperative neurological complications with ultrasound-guided interscalene and supraclavicular nerve blocks. Anaesthesia. 2011;66:168-174.
    16. Hahn C, Nagdev A. Color Doppler Ultrasound-guided Supraclavicular Brachial Plexus Block to Prevent Vascular Injection. West J Emerg Med. 2014;15:703-705.

    Interscalene

    INTERSCALENE BLOCK
    Author: Valeria Mossetti

    1. Indications
    Interscalene block provides anaesthesia and analgesia for surgery on shoulder, distal
    clavicle and proximal humerus.

    2. Contraindications
    – Local infection
    – This block should not be performed bilaterally because of the potentially
    respiratory problems originating from the phrenic nerve block, almost always
    present with this technique even with the ultrasound guide.

    3. Anatomy
    The interscalene roots of the brachial plexus (C5, C6, C7) run in the interscalene
    groove between the anterior and middle scalene muscles, which are located at the
    lateral border of the clavicular origin of the sternocleidomastoid muscle.

    4. Technique
    The patient is in supine position, the head is slightly turned away from the side to be
    blocked.

    Please click here to review the full article.

    Infraclavicular

    INFRACLAVICULAR BLOCK
    Author: Valeria Mossetti

    1. Indications
    Infraclavicular block provides anaesthesia and analgesia for surgery on humerus,
    elbow, forearm and hand.

    2. Contraindications
    Local infection

    3. Anatomy
    In the infraclavicular plane the cords of the brachial plexus surround the axillary
    artery and lie medial to the coracoid process of the scapula; the lateral cord is
    cephalad and lateral to the artery, the posterior cord is posterior to the artery, and the
    middle cord posterior and medial to the artery. The axillary vein lies medial to the
    artery.

    4. Technique
    The patient lies supine with shoulders in neutral position and the arm first lying at
    the side, then abducted and flexed at the elbow.
    Use a linear high-frequency probe with 10-12 MHz. For smaller patients, if possible,
    use a small footprint linear probe (25 mm). If required, identify the nerves using the
    nerve stimulator: common response to neurostimulator is the forearm and hand
    contraction.

    Please review the full article here.

    Axillary

    AXILLARY BLOCK
    Author: Valeria Mossetti

    1. Indications
    Axillary block provides anesthesia and analgesia for surgery on forearm and hand.
    For extensive elbow surgery consider more proximal technique.

    2. Contraindications
    Local infection

    3. Anatomy
    In the axilla, the terminal branches of the brachial plexus (ulnar, median, and radial
    nerves) meet near the artery. The musculocutaneus nerve, however, branches off
    more proximally from the plexus cords and proceeds from there dorsally and
    cranially while remaining near the plexus in the axillary region.

    4. Technique
    The patient is positioned as for a classical axillary approach, i.e. supine with the arm
    abducted at 90°C and the forearm flexed.
    Use a linear high-frequency probe with 10 or 12 MHz. For smaller patients, if
    possible, use a small footprint linear probe (25 mm). If required, identify the nerves
    using the nerve stimulator: common response to neurostimulator is the hand and
    fingers contraction.
    Place the probe perpendicularly on the arm as close to the axilla as possible in the
    hollow formed between the biceps and the pectoralis muscle so that the plexus can
    be scanned transversely…

    Please click here for the full article.

    Forearm nerves

    FOREARM NERVES
    Author: Valeria Mossetti

    1. Indications
    Anesthesia and analgesia for sorgere on hand.

    2. Complications
    Local infection
    MEDIAN NERVE
    The median nerve is in the middle between the palmaris longus tendon and the flexor
    radialis carpi tendon. This nerve can be easily followed up to the elbow to find the best
    position for the block.
    The patient is in supine position, the arm abducted at an angle of 90°C with the palm
    of the hand facing upward.
    Use a linear high-frequency probe with 10 or 12 MHz.
    Place the probe on the interior side of the wrist in a tangential plane so that the nerve
    can be scanned transversely (the marker on the probe is directed towards the patient‘s
    head).
    The median nerve is depicted as a well defined, independent, round and hyperechoic
    structure. In correspondence with the nerve fascicles

    Please click here for the full article.

    Truncal blocks

    usra_12

    Transversus Abdominus Plane Block

    Dr Richard Craig

    Content
    • Indications
      Specific contraindications
      Anatomy
      Technique
      Volume of LA
      Specific complications
      Self-Assessment
      Bibliography
    Indications

    The Transversus Abdominis Plane (TAP) block provides intraoperative and postoperative analgesia for upper and lower abdominal incisions, where an epidural is contraindicated or considered too invasive for the minor nature of the surgery.  TAP block has been described in paediatric patients for the following operations:

    • Colorectal surgery e.g. colostomy formation
    • Iliac Crest bone harvest site
    • Inguinal hernia repair
    • Laparoscopic and open Appendicectomy
    • Laparoscopic cholecystectomy
    • Laparoscopic nephrectomy
    • Renal transplant recipients

    Catheter techniques have also been described in the paediatric population.

    Specific contraindications

    Local infection at the proposed needle insertion point

    Anatomy
    • The skin of the anterior abdominal wall is supplied by the ventral rami of the inferior six thoracic nerves. These are the continuation of the T7 to T11 intercostal nerves and the subcostal nerve (T12).
    • The ventral ramus divides into a lateral cutaneous nerve and an anterior cutaneous nerve. These innervate the skin of the anterior abdominal wall.
    • The ventral rami of T 7 to T12 run in the plane between the transversus abdominis muscle and the internal oblique muscle – the Transversus Abdominis Plane.

    • The transversus abdominis muscle is the innermost of the flat muscles of the abdomen. It arises from the lateral third of the inguinal ligament, the anterior three-quarters of the iliac crest, the inner surfaces of the costal cartilages of the lower six ribs, and from the lumbodorsal fascia. Its insertion is the xiphoid process, the pubic crest and pectineal line (forms the conjoint tendon along with the internal oblique muscle aponeurosis) , and the linea alba (above the arcuate line it fuses with the posterior layer of the internal oblique aponeurosis to form the posterior wall of the rectus sheath, below the arcuate line the aponeurosis  of transversus abdominis lies anterior to the rectus abdominis muscle.
    • The transversalis fascia and the peritoneum are deep to the transversus abdominis muscle.
    • The quadratus lumborum muscle arises from the iliolumbar ligament and the adjacent portion of the iliac crest, and is inserted into the lower border of the 12th rib, and by four small tendons into the apices of the transverse processes of the L1 to L5 lumbar vertebrae.
    • The lumbar triangle of Petit is used to determine the needle insertion point in the landmark-based technique of performing a TAP block. The posterior border of the triangle is the latissimus dorsi muscle, the anterior border is the external oblique muscle, and the base is the iliac crest (Fig 3)

     

    Technique

    The following techniques have been described:

    • Ultrasound-guided mid-axillary approach
    • Ultrasound-guided anterior subcostal approach
    Ultrasound-guided mid-axillary approach
    • Position the patient supine.
    • Select a linear probe
    • The ultrasound machine is positioned on the far side of the patient, with the operator stood on the side to be blocked. For bilateral blocks less experienced operators will find the far side block harder to maintain needle visualisation.

    • Place the ultrasound probe in a transverse plane between the iliac crest and the costal margin.

    • Left-right probe orientation is easier if you start scanning over the linea alba in the midline and then move the probe laterally until it is between the iliac crest and the costal margin.
    • Identify the peritoneum and then the lateral abdominal muscles from deep to superficial (transversus abdominis, internal oblique, and external oblique).

    • In obese children fascial planes can appear within the subcutaneous adipose tissue, this can lead to confusion and misidentification of the muscle layers if the layers are identified from superficial to deep.
    • The target is the fascial plane between the transversus abdominis and the internal oblique muscles.
    • Use an in-plane needling technique . Choose a needle insertion point such that the needle is as perpendicular to the ultrasound beam as possible; this will result in the best possible image of the needle.
    • Advance the needle in an antero-posterior direction.
    • Aim to puncture the fascia on the deep aspect of the internal oblique muscle to have the needle tip on the transversus abdominis side of the fascial layer (a slight give or pop is often felt).

    Figure 5 Ultrasound image of lateral abdominal wall of infant, needle inserted from anterior to posterior using an in plane needling technique. A 10MHz linear probe is positioned in the transverse plane midway between the iliac crest and costal margin.

     

    • In neonates you should see a neat lens-shaped deposit of local anaesthetic forming between the transversus abdominis muscle and the fascia separating the internal oblique muscle and transversus abdominis (Fig 6). In older children strands can be seen stretching between the two muscles.
    • Aim to deposit the injectate at the posterior part of the TAP; at or posterior to the mid-axillary line. There is potential to miss the L1 nerve branches should the injection be made too posterior as the nerve may not have passed into the TAP yet.

    Figure 6 Ultrasound image of lateral abdominal wall of infant, needle inserted from anterior to posterior using an in plane needling technique. Note the spread of local anaesthetic between the inner most muscles. In small children it is common for the local anaesthetic to back track along the needle path as is seen here by the ‘fluffing’ of the interior oblique muscle.

     

    • If you see local anaesthetic spreading within the internal oblique muscle superficial to the fascia between internal oblique and transversus abdominis, reposition the needle tip deep to the fascia.
    • It can prove difficult to enter the TAP, if so; place the needle in the transversus abdominis muscle. As you withdraw the needle have an assistant inject, as the needle tip passes into the TAP space
    Ultrasound guided anterior subcostal approach
    • The patient is placed supine.
    • The ultrasound probe is placed over the subcostal area in an oblique transverse plane, parallel to the subcostal margin. lateral to the rectus sheath.
    • Identify the medial border of the external oblique, internal oblique and transversus abdominis muscles. Identify the TAP. Insert the block needle at the lateral edge of rectus abdominis. Advance the needle in-plane away from the midline and parallel to the costal margin. Hydro-dissect the plane.

    Volume of LA

    0.3-0.5ml/kg/side of 0.25% levobupivacaine.

    Top Tip

    Always use an in plane needling technique
    Always identify the abdominal muscle from deep to superficial.
    In larger patients (where a steeper angle of needle trajectory is required) needle enhancing software may improve the view.
    If you are finding difficulty entering the TAP plane carefully enter the transversus abdmonis muscle with your needle. On withdrawing the needle have your assistant inject, as the bevel withdraws into the plane you will see a splitting of the muscle layers.

    Specific complications
    • Peritoneal perforation
    • Organ perforation (in neonates the liver and spleen are particularly prominent)
    Self-Assessment
    1. Unilateral TAP block is indicated for
      a) Laparotomy
      b) Cholecystectomy
      c) Laparoscopic appendicectomy
      d) Pyloromyotomy
      e) Inguinal Herniorrhaphy
    2. Label the image below
      A anterior
      B posterior
      C Transversus Abdominis muscle
      D Internal Oblique muscle
      E External Oblique muscle
      F Peritoneum

    Bibliography
    • Carney J, Finnerty O, Rau J, Curley G, et al. Ipsilateral transversus abdominis plane block provides effective analgesia after appendicectomy in children: a randomised controlled trial. Anesthesia & Analgesia. 2010. Vol. 111, 4, pp. 998-1003.
    • Carney J, Finnerty O, Rauf J, et al. Studies on the spread of local anaesthetic solution in transversus abdominis plane blocks. Anaesthesia. 2011. Vol. 66, pp. 1023-1030.

    Rectus sheath

    Dr Richard Craig

    Content
    • Indications
      Specific contraindications
      Anatomy
      Technique
      Volume of LA
      Specific complications
      Self-Assessment
      Bibliography
    Indications

    A rectus sheath block provides intraoperative and postoperative analgesia for mid-line abdominal incisions. Specifically, it may be useful for the following operations:

    • Umbilical hernia repair
    • Paraumbilical hernia repair
    • Epigastric hernia repair
    • Pyloromyotomy
    • Laparoscopic surgery
    • Abdominoplasty
    • Excision of urachal remnants
    • Duodenal atresia repair

    Rectus sheath catheters have been used for upper abdominal surgery (1). The rectus sheath block has also been used for chronic pain management for patients with abdominal cutaneous nerve entrapment, myofascial pain syndrome, and iatrogenic nerve injury. (2)

    Specific contraindications

    Local infection

    Anatomy
    • The skin of the anterior abdominal wall is supplied by the ventral rami of the inferior six thoracic nerves. These are the continuation of the T7 to T11 intercostal nerves and the subcostal nerve (T12). The anterior cutaneous branch of the ventral rami passes through the posterior of the rectus sheath. The rectus abdominis muscle originates from the pubic symphysis and pubic crest, and inserts into the xiphoid process and 5th to 7th costal cartilages. It is innervated by the ventral rami of the inferior six thoracic nerves.
    • The two rectus muscles are separated by the linea alba. The lateral border of the rectus muscle and its sheath form the linea semilunaris.

    • The rectus sheath encloses the rectus abdominis muscles and is formed by the aponeuroses of the three flat abdominal muscles; the external oblique, internal oblique and the transversus abdominis muscles. The external oblique aponeurosis and the anterior layer of the internal oblique aponeurosis form the anterior wall of the rectus sheath. The transversus abdominis aponeurosis and the posterior layer of the internal oblique aponeurosis form the posterior wall of the sheath. The fibres of the anterior and posterior walls of the sheath interlace in the mid-line to form the linea alba.

    • The inferior quarter of the posterior wall of the rectus sheath is deficient; the arcuate line forms the inferior border of the posterior wall of the rectus sheath. The arcuate line is midway between the umbilicus and the pubic crest.
    • The anterior layer of the rectus sheath is firmly attached to the rectus abdominis muscle at three tendinous intersections. These are usually located at the level of the xiphoid process, the umbilicus and half-way in between. The tendinous intersections do not extend through the whole rectus abdominis muscle to the posterior sheath; It is because of this local anaesthetic can spread caudad and cephalad in the plane between the rectus muscle and the posterior rectus sheath.
    • The superior and inferior epigastric vessels and the terminal parts of the inferior five intercostal and subcostal vessels and nerves are located within the rectus sheath. The inferior epigastric artery is a branch of the external iliac artery. It runs superiorly in the transversalis fascia to enter the rectus sheath at the arcuate line. The superior epigastric artery is a branch of the internal thoracic artery (internal mammary artery) and it enters the rectus sheath just inferior to the 7th costal cartilage.
    US technique
    • The patient is placed supine.
    • Ensure yourself and the ultrasound machine are placed ergonomically.
    • Select the estimated ultrasound depth. In neonates this will usually be 2cm, infants 3cm, thereafter 4cm depth is usually an appropriate starting scanning depth.
    • A linear probe is placed transverse on the abdomen, just above the umbilicus.

    ULTRASOUND OF NEONATAL ABDOMEN IN TRANSVERSE PLANE. A – AORTA, L – LINEA ALBA, R – RECTUS MUSCLE

    • Select highest appropriate frequency for the initial scanning depth.
    • The initial image will have the linea alba in the midline with a rectus abdominis muscle either side.

    ULTRASOUND OF INFANT ABDOMEN IN TRANSVERSE PLANE. WHITE ARROW – BOWEL, BLUE ARROW FASCIA TRANSVERSALIS AND PERITONEUM, RED ARROW POSTERIOR FASCIA,L – LINEA ALBA, R – RECTUS MUSCLE.

    • Move the probe laterally and scan the rectus abdominis muscle in the transverse plane. As the probe is moved laterally the semilunaris (lateral border) is visualised.

    • Just lateral to the semilunaris the 3 lateral muscles are seen to come together.
    • Note in neonates the muscle will only be a couple of millimetres thick.
    • In larger children it is possible to identify the epigastric vessels with Doppler. Ensure the probe pressure is minimal.
    • Deep to the rectus sheath is a continuous hyperechoic line that is the peritoneum, it crosses the midline.
    • Insert the block needle in-plane, the puncture point should be suitably lateral that the needle will have a shallow trajectory.

    ULTRASOUND OF NEONATAL ABDOMEN IN TRANSVERSE PLANE. NEEDLE HAS A SHALLOW TRAJECTORY COMING FROM LATERAL TO MEDIAL, AND THE BEVEL IS UPPERMOST. THE ANTERIOR  SHEATH IS TENTED. THIS CHILD HAS HEPATOMEGALY SECONDARY TO HEART FAILURE, NOTE THE LIVER DIRECTLY BENEATH THE RECTUS MUSCLE. L – LINEA ALBA (MIDLINE), R – RECTUS MUSCLE (NOTE HOW THIN THE MUSCLE IS IN THE NEONATE, APPROXIMATELY 2MM THICK)

    • Note it can be difficult to puncture the skin, either lift the skin and push the needle through or make a knick in the skin using a sharp bevelled needle.
    • Aim to position the tip of the needle between the rectus abdominis muscle and the posterior rectus sheath.
    • Stop the needle tip just superficial to the first white line (the posterior sheath) as a ‘pop’ is not felt or seen in all patients.
    • Aspirate and inject 0.25-0.5mls, if the tip is in the correct plane the muscle is peeled off the posterior sheath. If the needle tip remains too superficial then an intramuscular injection occurs; then the needle is carefully advanced.

    ULTRASOUND OF NEONATAL ABDOMEN IN THRANSVERSE PLANE. THE LOCAL ANAESTHETIC (LA) PEELS THE POSTERIOR SHEATH OFF THE RECTUS MUSCLE.

    • The tissues are often quite tough even in a neonate; therefore a steady pressure may be required.
    • A ‘pop’ is not always present and it may be necessary to repeat the test injection of local anaesthetic.
    • In neonates prevent waste of precious local anaesthetic by using saline to detect the correct plane.
    • Deposit local anaesthetic in the potential space between the rectus abdominis muscle and the posterior aspect of the sheath.
    • After injection spread can be assessed by turning the probe in the paramedian longitudinal plane, local anaesthetic will be seen to spread beneath the tendinous intersections.

    ULTRASOUND OF NEONATAL ABDOMEN IN PARAMEDIAN LONGITUDINAL PLANE. WHITE ARROW – SEMIRENTNDINOUS INTERSECTION (NOTE THAT IT IS NOT FIRMLY ATTACHED POSTERIORLY).

    (Insert still ultrasound images and video of block.)

    Volume of LA
    • A volume of 0.1 ml/kg/side of 0.25% levobupivacaine has been shown to be adequate for umbilical hernia repair (3).
    • For neonates 0.125% levobupivacaine is effective.
    • A larger volume will potentially spread from the xiphoid to the pubis; Up to a total of 0.8 ml/kg 0.25% levobupivacaine may be used.
    • The absorption kinetics of ropivacaine are slower after a rectus sheath block than after other compartment blocks (4).
    Specific complications
    • Peritoneal puncture
    • Perforation of the bowel
    • Visceral puncture
    • Major vessel puncture
    • Mesenteric vessel puncture
    • Inferior epigastric vessel puncture
    • Retroperitoneal haematoma.
    Top tips
    • Ensure a shallow trajectory
    • Not every patient has a ‘pop’ on entering the correct plane
    • In neonates use 0.125% levobupivacaine
    Self-assessment questions
    Bibliography
    1. Comish P, Deacon A. Rectus sheath catheters for continuous analgesia after upper abdominal surgery. ANZ Journal of Surgery. 2007. Vol. 77, p. 84.
    2. Skinner AV, Lauder GR. Rectus sheath block: successful use in the chronic pain managment of pediatric abdominal wall pain. Paediatric Anaesthesia. 2007. Vol. 17, 12, pp. 1203-11.
    3. Willschke H, Bosenberg A, Marhofer P, Johnston S, Kettner SC, Wanzel O, Kapral S. Ultrasonography-guided rectus sheath block in paediatric anaesthesia – a new approach to an old technique. British Journal of Anaesthesia. 2006. Vol. 97, 2, pp. 244-9.
    4. Wada M, Kitayama M, Hashimoto H, Kudo T, Kudo M, Takada N, Hirota K. Brief reports: plasma ropicacaine concentrations after ultrasound guided rectus sheath block in patients undergoing lower abdominal surgery. Anesthesia & Analgesia. 2012. Vol. 114, 1, pp. 230-2.

    Ilioinguinal/iliohypogastric block

    Dr Richard Craig

    Content
    • Introduction
      Indications
      Specific contraindications
      Anatomy
      Technique
      Volume of LA
      Specific complications
      Bibliography
    Indications

    The ilioinguinal-iliohypogastric nerve block provides intraoperative and postoperative analgesia for inguinal surgery.
    It may be useful for providing analgesia for:

    • Inguinal hernia repair
    • Orchidopexy
    • Hydrocoele repair
    • Varicocoele surgery

    It has also been used, in combination with T11 and T12 intercostal nerve blocks, to provide post-operative pain relief after renal transplant. (1)
    Its use in adult patients undergoing laparotomy via a Pfannenstiel incision did not result in a reduction in pain score, length of hospital stay, or postoperative morphine consumption. (2)

    The block is also used in chronic pain management for patients with persistent inguinal post-herniorrhaphy pain, however, a recent study concluded that the block was not useful for either the diagnosis or management of this condition. (3)

    Specific contraindications

    Local infection

    Anatomy
    • The ilioinguinal and iliohypogastric nerves form part of the lumbar plexus.
    • They are branches of the primary ventral ramus of L1 and receive a branch from the 12th spinal nerve.
    • The L1 primary ventral ramus enters the upper part of psoas major where it branches into the ilioinguinal and iliohypogastric nerves.
    • The nerves emerge at the lateral border of psoas major and pass anterior to quadratus lumborum. They pierce the lumbar fascia at the lateral border of quadratus lumborum and run in the plane between the internal oblique muscle and transversus abdominis muscles.
    • The iliohypogastric nerve runs superior to the ilioinguinal nerve.
    • The iliohypogastric nerve divides into a lateral cutaneous branch and a medial (or anterior) cutaneous branch at the level of the iliac crest. The lateral cutaneous branch pierces the internal and external oblique muscles immediately above the iliac crest to supply skin of the gluteal region. The medial cutaneous branch pierces the internal oblique muscle and external oblique aponeurosis to supply the skin above the inguinal ligament and the suprapubic region (i.e. the hypogastric region).
    • The ilioinguinal nerve pierces the internal and external oblique muscle to reach the lower border of the spermatic cord or round ligament of the uterus and enters the inguinal canal. It supplies sensation to the skin of upper medial thigh and the upper part of the scrotum and root of the penis or the skin over labium majus and the mons pubis.
    • A study of 25 neonatal cadavers measured the distance from the anterior superior iliac spine (ASIS) to the ilioinguinal and iliohypogastric nerves on a line connecting the ASIS to the umbilicus. (4) The left and right ilioinguinal nerves were 1.9 ± 0.9 mm (mean ± SD) and 2.0 ± 0.7 mm (mean ± SD) from the ASIS. The left and right iliohypogastric nerves were 3.3 ± 0.8 mm and 3.9 ± 1.0 mm from the ASIS.
    • An ultrasound study involving 50 patients with a mean age of 40 months and a mean weight of 13 kg, reported a mean distance from the ASIS to the ilioinguinal nerve of 6.7 (SD2.9)mm,  and a mean distance from the ilioinguinal nerve to the peritoneum of 3.3 (SD1.3) mm. (5)
    • The fascial plane between the transversus abdominis muscle and the transversalis fascia is in continuity with the space around the femoral nerve.

     

    Technique

    Ultrasound-guided

    Position the patient supine.
    Use a high frequency linear probe (10Mhz or greater).
    Place the probe on the anterior abdominal wall along the line joining the anterior superior iliac spine (ASIS) and the umbilicus.

    Position the probe such that the bony shadow from the ASIS is visible on one side of the image on the screen. Identify the peritoneum, transversus abdominis muscle, and internal oblique muscle. The external oblique muscle may not be visible as a distinct muscle layer at this level.
    Sliding the probe in a cephalad direction up over the iliac crest, whilst maintaining the orientation of the probe along a line to the umbilicus, will bring all three muscles into view as three distinct layers. This may be useful if there is any doubt about the anatomy and the relevant planes. Always identify the deepest structures first (i.e. the peritoneum) and work toward the superficial structures to identify each layer.

    The ilioinguinal and iliohypogastric nerves are seen in close proximity to one another as two small round hypoechoic structures with a hyperechoic border. They lie in the plane between the internal oblique muscle and the transversus abdominis muscle close to the ASIS (in a study involving 50 children of mean age 40 months the mean distance from the ilioinguinal nerve to the ASIS was 6.7 mm). (5)

    REMEMBER TO ALWAYS IDENTIFY THE MUSCLE LAYERS FROM THE INSIDE OUT.

    Perform a dynamic scan, adjusting probe angle, the gain, and the depth to obtain the best possible image of the nerves and surrounding structures.
    Note that it may not always be easy to visualise the nerves due to the variability of nerve anatomy distal to the midaxillary line, if in doubt place the local anaesthetic in the transversus abdominis plane.
    Insert the block needle in plane from medial to lateral and ensure that there is a good image of the needle tip at all times as the needle is advanced. Deposit local anaesthetic around the nerves in the transversus abdominis plane.

    Landmark technique

    This block has a high failure rate and complications such as femoral nerve block and peritoneal puncture are more likely than with the ultrasound guided block (5). In a study of 50 children of mean age 40 months the mean distance from the ilioinguinal nerve to the peritoneum was 3.3 mm (5).
    The needle insertion point should be approximately 2.5 mm (range 1.0 – 4.9mm) medial to the ASIS on a line drawn between the ASIS and the umbilicus (4). Use a short bevelled needle. Insert the needle just through the skin into the subcutaneous tissues and then advance the needle slowly until a fascial click or loss of resistance is felt. This occurs as the external aponeurosis is pierced. Inject the local anaesthetic at this depth, between the external and internal oblique.

    Volume of LA

    In expert hands as little as 0.075 ml/kg of 0.25% levobupivacaine for ultrasound guided blocks (6).
    0.3 ml/kg of 0.25% levobupivacaine for the landmark technique (5).

    Specific Complications

    Block failure (up to 30% is some series using the landmark technique (5))
    Colon puncture, small bowel puncture, pelvic retroperitoneal haematoma, bowel haematoma,
    Transient femoral nerve palsy with transient quadriceps paresis. The latter complication has an incidence of up to 6% with the landmark technique (7). The quadriceps paresis resolves within hours.

    Bibliography

    1. Shoeibi G, Babakhani B, Mohammadi SS. The efficacy of ilioinguinal-iliohypogastric and intercostal nerve co-blockade for postoperative pain relief in kidney recipients. Anesthesia & Analgesia. 2009. Vol. 108, 1, pp. 330-3.
    2. Wehbe SA, Ghulmiyyah LM, Dominique el-KH, Hosford SL, Ehleben CM, Saltzman SL, Sillis ES. Prospective randomized trial of iliohypogastric-ilioinguinal nerve block on post-operative morphine use after inpatient surgery of the female reproductive tract. Journal of Negative Results in Biomedicine. 2008. Vol. 7, 11, p. 1477.
    3. Bischoff JM, Koscielniak-Nielsen ZJ, Kehlet H, Werner MU. Ultrasound-guided ilioinguinal/iliohypogastric nerve blocks for persistent inguinal postherniorrhaphy pain: a randomized, double-blind, placebo-controlled trail. Anesthesia & Analgesia. 2012. Vol. 114, 6, pp. 1323-9.
    4. van Schoor AN, Boon JM, Bosenberg AT, Abrahams PH, Meiring JH. Anatomical considerations of the pediatric ilioinguinal/ iliohypogastric nerve block. Pediatric Anesthesia. 2005. Vol. 15, pp. 371-7.
    5. Willschke H, Marhofer P, Bosenberg A, Johnston s, Wanzel O, Cox SG, Sitzwohl C, Kapral S. Ultrasonography for ilioinguinal/ iliohypogastric nerve blocks in children. British Journal of Anaesthesia. 2005. Vol. 95, 2, pp. 226-30.

    Thoracic Paravertebral Block

    Dr Naveen Raj

    Content
    • Introduction
    • Indications
    • Specific contraindications
    • Anatomy
    • Technique
    • Volume of LA
    • Specific complication
    • Bibliography
    Introduction

    Paravertebral block is a technique where local anaesthetic is injected into the space adjacent to the vertebrae to block the spinal nerves as they emerge from the intervertebral foramen. Here the spinal nerves are devoid of covering fascia making them sensitive to the action of local anaesthetics. The block is of high quality and sufficient to provide analgesia for major surgery at various sites. A single site injection can provide blocks of 4-6 dermatomes. It can be performed at the Cervical, Thoracic or Lumbar level; however only the Thoracic Paravertebral block will be discussed here.

    Thoracic paravertebral block confers several advantages over epidural block:

    • Comparable pain relief with reduced side effects.
    • Better pulmonary function and fewer pulmonary complications
    • Contraindications to thoracic epidural block do not preclude thoracic paravertebral block e.g.  systemic sepsis, deranged coagulation
    Indications

    Both single shot unilateral or bilateral Paravertebral blocks and continuous infusions via placement of catheter into the site of block can be used to provide perioperative analgesia for various surgical procedures of the chest wall, thorax and abdomen (* indicates bilateral block).

    • Thoracotomy
    • Sternotomy * including cardiac and chest wall correction  surgery
    • Breast surgery
    • Renal and Ureteric surgery
    • Cholecystectomy
    • Orchidopexy
    • Fundoplication
    • Appendicectomy
    • Hernia repair
    • Laparascopic procedures
    • Major  abdominal surgery

    It also can be used in nonsurgical acute and chronic pain management:

    • Fractured ribs
    • Lung contusions
    • Benign and malignant neuralgia
    • Complex regional pain syndromes
    Specific Contraindications
    • Tumour in the paravertebral space
    • Empyema
    • Infection at site of block
    • Caution in those with previous thoracotomy and chest deformities including kyphoscoliois
    Anatomy

    The Thoracic paravertebral space is a wedge shaped space adjacent to the Thoracic vertebral column. The boundaries of the space are:

    • Medial – the vertebral body and intervertebral foramen.
    • Antero-lateral – Pleura.
    • Posterior – Costo-transverse ligament and the internal intercostal membrane laterally. These two structures are continuous with one another.

    Fig 1. Boundaries of the paravertebral space

    Contents of the space include:

    • Adipose tissue
    • Anterior ramus of Spinal (Intercostal) nerves
    • Posterior ramus of Spinal (Intercostal) nerves
    • Sympathetic chain
    • Rami communicantes

    Thoracic paravertebral space communicates with:

    • Medially – Epidural space
    • Laterally – Intercostal space
    • Superiorly – Cervical paravertebral space
    • Inferiorly –limited spread due to the origins of the Psoas Major muscle

    Eleven Intercostal nerves (T1-T11) and one Subcostal Nerve (T12) arise from spinal cord and exit the intervertebral foramen on both sides of the vertebral column to divide immediately into an anterior and posterior division.

    • The posterior division – divides into medial and lateral branches and supplies the muscles and skin of the posterior part of the chest.
    • The anterior divisions initially lie between the pleura and the posterior intercostal membrane and then continue between the innermost and inner intercostal muscles to terminate as the anterior cutaneous branch of the thorax. A lateral branch is given off midway between the vertebral body and the sternum approximately at the mid axillary line which in turn divides into anterior and posterior branches.

    Fig 2. Course of the thoracic intercostal nerves

    • The anterior divisions of T2 -6 are limited to the thorax and are called thoracic intercostals nerves.
    • The anterior divisons of T7-T11 in addition continues into the abdomen to run between the Internal Oblique and Transverse Abdominis to supply skin and muscles of the anterior abdomen and hence are called thoracoabdominal intercostals nerves. They pierce the rectus sheath to terminate as the anterior cutaneous branches of the abdomen
    • The anterior division of T12 runs along the lower border of the 12th rib and then into the abdomen similar to the lower intercostals nerves. The lateral branch does not divide into anterior and posterior division. It pierces the external oblique muscles and descends over the iliac crest to supply the skin over the front part of the gluteal region as far as the level of greater trochanter

    Technique
    • In our current practice the anaesthetised child is placed in the lateral position with the side to be blocked uppermost (fig 4A&B)). The block can also be done in the prone position and in those who are awake it is best done sitting up, leaning forward.
    • Position the ultrasound machine appropriately, generally on the opposite side of the patient to the operator.

    Fig 4A

    Fig. 4B

    • Level of the block:
      o T4 for Sternotomy
      o T6 for Thoracotomy
      o T10 for Abdominal procedures
    • Equipment: Standard block needle, 40-50mm length for small children and smaller, longer needles will be required for older children depending on needling technique used.
    • If inserting a catheter then appropriate kit needs to be selected.
    • Sterility: As there is epidural spread of the injectate all measures to maintain sterility should be taken. For single shot blocks we use a sterile non touch technique with gloves, drapes and US cover and sterile gel. When inserting catheters then full aseptic precautions are taken.
    • Identify and mark the spinous process at the appropriate level where the block is to be done.
    • There are 2 main approaches –
      o A) Probe in transverse plane Fig 5
      o B) Probe in sagittal plane   Fig 6

    Fig. 5

     

    Fig. 6

    A) Probe Transverse – Needle In-Plane Approach

    • Select an appropriate sized US probe. For neonates and infants a 25mm linear probe, for older children a larger probe of approx. 35mm. is chosen.
    • Place the probe in  transverse plane over the midline at the chosen vertebral level
    • Probe orientation preferred by the author – orientation mark is on medial side.
    • Identify the spinous process (SP) of the thoracic vertebrae
    • Move the probe laterally in this plane and view the lamina and lateral to this the hyperechoic transverse process (TP) with acoustic shadow beneath (Fig 7,8)

    Fig 7. Transverse Plane Mid-Thoracic level. PVS – paravertebral space, SP – spinous process, TP – start of transverse process.

    Fig 8. Transverse Plane Mid-Thoracic level. PSM – paraspinal muscles, PVS – paravertebral space, SP – spinous process, TP –transverse process.

    • Identify the rib and intercostal muscles lateral to the transverse process (Fig 9).

    Fig 9. Transverse Plane Mid-Thoracic level. PSM – paraspinal muscles, TP – tip of transverse process

    • Identify the pleura beneath (Fig 10). For the best view and a successful block you should ensure the pleura is visible as a bright white solid line with characteristic appearance of intercostal muscles above.

    Fig 10. Transverse Plane Mid-Thoracic level. ICM – internal intercostal membrane, PSM – paraspinal muscles, PVS – paravertebral space, TP – tip of transverse process. Note the internal intercostal membrane is continuous with the costotransverse membrane.

    • The transverse process with its acoustic shadow should be close to one end of the screen and opposite to the side of needle insertion.
    • The needle should be inserted in-plane from the lateral to medial direction aiming for the junction of the pleura and the acoustic shadow underneath the transverse process (Fig 11).

    Fig 11. Probe –needle position.

    • The needle should pass through the intercostals muscle (Fig 12) and the needle tip should end in a hypoechoic triangular space formed by the acoustic shadow underneath the transverse process medically, pleural antero-laterally and the lower border of the intercostals muscles posteriorly. A subjective subtle “give” may be felt as the lateral costo-transverse ligament or internal costal membrane is pierced prior to entering the space.

    Fig 12. Transverse Plane Mid-Thoracic level showing in plane technique needle travelling lateral to medial. ICM – internal intercostal membrane, PSM – paraspinal muscles, PVS – paravertebral space, TP – tip of transverse process.

    • Correct placement of the needle in the thoracic Paravertebral space should be confirmed by the anterior displacement of pleural upon injection of a small bolus of saline or local anaesthetic (Fig 13-16).
    • Once confirmed the required volume of local anaesthetic should be injected.
    • Watch the VIDEO of the paravertebral block in a 2kg neonate by clicking on the clipframe below

    Fig 13.

    Fig 14. Paravertebral space entered by needle, pleura displaced anteriorly by local anaesthetic.

    Fig 15. Paravertebral space entered by needle, pleura displaced anteriorly by local anaesthetic. TP –transverse process. Local anaesthetic spread marked in light blue

    Fig 16. Paravertebral space filled by local anaesthetic. TP –transverse process.

    • In cases where an appropriate size US probe is unavailable (35mm probe and infant combination) or in those situations where the rib or scapula comes in the way of completing the transverse intercostal in-plane approach as described above; then a  Transverse Probe – Needle Out of plane approach can be implemented
    • The needle is inserted at mid point of the probe and is directed in a perpendicular manner to the tissue planes to enter the paravertebral space. The needle is only visible as a white dot and tissue plane movement or injection of small volume of saline assists in ascertaining the position of the needle tip.

    B) Probe Sagittal – Out of Plane Needle Approach

    • Place an appropriate size US probe in sagittal plane over the midline. The spinous processes will be observed. Slide the probe laterally so that it is positioned parallel to the vertebral column.
    • The level of the intended block should be in the middle of the probe.
    • Move the probe laterally in the same plane to visualise the acoustic window between the transverse processes (Fig 17). The Paravertebral space is usually not clearly visible in this plane. Occasionally the costo-transverse ligaments can be identified. The pleura with lung beneath is clearly visible more anteriorly.
    • Kamarkar et al have demonstrated that the ligaments and pleura are visualised better if the probe is tilted slightly lateral.

    Fig 17. Probe – needle orientation for out of plane technique.

    • Probe orientation preferred by the author – orientation mark is directed cranially.
    • Identify the hyperechoic round transverse process with its anechoic shadow beneath (Fig 18).

    Fig 18. Parasagittal plane at mid-thoracic level. CTL – costotransverse ligament, PVS – paravertebral space, TP – transverse process.

    • The needle should be introduced near the middle of the probe at the level of the lower transverse process. The needle should be aimed for the junction of shadow between the caudal part of the upper transverse process and the pleura.
    • The needle will only be visible as a white dot; tissue plane movement or injection of a small volume of saline assists in ascertaining the position of the needle tip (Fig 19-20). Needle position is confirmed by the anterior displacement of pleura and widening of the Paravertebral space on injection.Fig 19A and 19B. Parasagittal plane at mid-thoracic level showing initial injection of saline to assess needle tip position, note the anterior displacement of the pleura. TP – transverse process.

    Fig 19A

    Fig 19B

    Fig 20A and 20B. Parasagittal plane at mid-thoracic level showing spread of local anaesthetic to adjacent paravertebral levels. TP – transverse process.

     Fig 20A

    • After careful aspiration local anaesthetic is injected.
    • Spread can be assessed with ultrasound, in neonates spread into the epidural space may be observed.
    • A catheter can then be inserted into the space so that the tip lies 2-3 cm beyond the tip of the needle. Catheter insertion is not easy and will require some needle manipulation.
    • An In-plane approach is possible in bigger children and adults; the needle being introduced in plane from a caudal to cranial direction.
    Local Anaesthetic and dosage
    • Depends on availability and preference of the operator.
    • L-Bupivacaine & Ropivacaine are commonly used.
    • In our current practice we use 0.25% L-Bupivacaine, 0.3-0.5 ml-1 kg per side
    • Adjunct drugs:
      Clonidine or Fentanyl 1 to 2 micrograms-1 ml may be useful. With the spread of the local anaesthetic into the epidural space these adjuncts are useful in improving the quality and duration of the block. Clonidine can be associated with hypotension and bradycardia.
    Side effects/complications
    • Sympathetic blockade leading to hypotension and fall in heart rate.
    • Epidural spread of local anaesthetic.
    • Pneumothorax.
    • Bleeding.
    • Epidural/Intrathecal spread.
    • Hypotension.
    • Infection.
    • Nerve injury.
    Bibliography
    • Manoj Kamarkar. Thoracic Paravertebral block. Anesthesiology 2001; 95:771-80
    • Manoj Kamarkar. Ultrasound guided Thoracic Paravertebral block. Techniques in regional anesthesia and pain management 2009; 13: 142-9
    • JE Chelly. Paravertebral blocks. Anesthesiology Clinics 2012; 30: 75-90
    • J Richardson, PA Lonnqvist and Z Naja. Bilateral Thoracic Paravertebral Block: potential and practice. British Journal of Anaesthesia 2011; 106: 164-71
    • Prema Thavaneswaran, Glenda Rudkin, Rodney Cooter, et al. Paravertebral block for anesthesia: a systematic review. Anesthesia and Analgesia 2010: 110: 1740-4
    • A Schnabel, SU Reichl, P Kranke, et al. Efficacy and safety of paravertebral blocks in breast surgery: a meta-analysis of randomised controlled trials. British Journal of Anaesthesia 2010; 105: 842-52
    • Bhatnagar S, MishraS, Madhurima S, et al. Clonidine as an analgesic adjuvant to continuous paravertebral bupivacaine for post-thoracotomy pain. Anaesthesia and Intensive care 2006; 34: 586-91
    • M Scarci, A Joshi, R Attia. In patients undergoing thoracic surgeryis paravertebral block as effective as epidural analgesia for pain management? Interactive Cardiothoracic and Vascular Surgery 2010; 10: 92-96
    • MJ Eason and R Wyatt. Paravertebral block- a reappraisal. Anaesthesia 1979; 34: 634-42
    • DJ Daly and PS Myles. Update on the role of paravertebral blocks for thoracic surgery: are they worth it? Current Opinion in Anesthesiology 2009; 22: 38-43

    Lower Limb

    usra_63

    Femoral Nerve Block

    By Dr Jacinth Tan

    • Fast, safe and effective procedure.
    • In patients undergoing surgery: Reduces the amount of general anaesthetic and opioid analgesics needed intraoperatively1, reduces post-operative pain and analgesic consumption1, 2, and may even reduce the length of hospital stay2.
    • In patients not undergoing surgery: Reduces the pain from hip fractures, provides longer duration of analgesia, reduces the analgesic doses needed and reduces the number of nursing interventions3.

    Indications:

    Surgical procedures to:

    • Hip joint.
    • Femur (e.g. femoral fractures)4.
    • Knee (e.g. knee arthroscopies, ACL reconstructions, patella ligament realignment)4:
      • For anterior knee procedures: A femoral nerve block alone may suffice4
      • For coverage of the medial aspect of the knee: Obturator nerve block should be added4
      • For coverage of the lateral aspect of the knee: Lateral femoral cutaneous nerve block should be added4
      • For coverage of the posterior aspect of the knee: Sciatic nerve block should be added4
    • Anterior thigh (e.g. skin graft from the anterior aspect of the thigh) 5.
    • Medial aspect of the leg (by blocking the saphenous nerve—a terminal cutaneous branch of the femoral nerve).
    • In combination with a popliteal block, analgesia can be provided for any procedure on the lower leg and foot5.
    • In combination with a high sciatic block and an obturator nerve block, analgesia can be provided for the entire lower extremity5.

    Contraindications:

    • Local infection at the proposed needle insertion point.
    • Situations where dense sensory block may mask the onset of lower extremity compartment syndrome (especially if combined with a sciatic block). E.g. Fresh fractures of the tibia/ fibula, or extensive and traumatic elective orthopaedic procedures to the tibia and fibula. Best practice will be to consult with one’s surgical colleagues as to the likelihood of compartment syndrome.6

    Anatomy:

    • The femoral nerve is the largest nerve that arises from the lumbar plexus, which forms within the body of the psoas major muscle.
    • It is derived from the anterior rami of nerve roots L2-4.
    • It emerges from the lower lateral border of the psoas muscle, descends between the psoas major and iliacus muscles, and then enters the thigh lateral to the femoral artery under the inguinal ligament.
    • At the femoral crease, the nerve lies on the surface of the iliacus muscle and is covered by the fascia lata and fascia iliaca. It lies outside of the femoral sheath that contains the femoral vessels.


    Figure 1: The femoral nerve and its relations in the inguinal region

    • Within the femoral triangle, it divides into the anterior and posterior divisions:
    • Anterior division
      • Sensory: Intermediate & medial cutaneous nerves of the thigh
      • Motor: Pectineus & sartorius
    • Posterior division
      • Sensory: Saphenous nerve
      • Motor: Quadriceps femoris
      • Articular branches to the hip and knee
    Dermatomal innervation5:

    Antero-medial thigh ((femoral nerve), knee (femoral nerve), medial aspect of the leg below the knee down to the foot (saphenous)

    Myotomal innervation5:

    Sartorius, Quadriceps Femoris (rectus femoris, vastus lateralis, intermedius and medialis), Pectineus, Iliopsoas

    Osteotomal innervation5:

    Anterior wall of hip joint, anterior aspect of femur, anteromedial walls of knee joint

    Sonocharacteristics of the femoral nerve:

    • Usually fairly superficial.
    • Under the fascia lata (most superficial) and fascia iliaca (immediately adjacent to the nerve & separates the nerve from the artery).
    • Lateral to the femoral artery and vein.
    • Triangular shaped or oval/ flattened as the nerve fans out into multiple branches.
    • Speckled and hyperechoic.
    • Becomes less obvious as it branches out caudally.


    Figure 2: Sonoanatomy of the femoral nerve

    Practical conduct of the block:

    • Position the patient supine with mild abduction of the ipsilateral leg.
    • Attention should be paid to ergonomics to facilitate successful block placement. Position the ultrasound machine so that visualisation of the screen, ultrasound probe and the operator’s hands can be done without needing to turn one’s head. This may be achieved by placing yourself on the side to be blocked and the machine on the far side of the patient.
    • Choose a high frequency linear probe (the femoral nerve is fairly superficial).
    • Place the probe along the line of the inguinal crease.
    • Begin by identifying the circular, anechoic and pulsating femoral artery at the level of the inguinal crease. If this is not immediately visible:
      • Slide the transducer medially or laterally
      • Check the depth setting
      • Use colour flow Doppler to help identify the vessels.
      • If 2 arteries are seen, move your probe cephalad.4
    • The nerve usually appears as a hyperechoic speckled triangular or oval shaped structure lateral to the artery.
    • Follow the nerve along its course to locate where it divides (note this can start above the inguinal ligament in some subjects)—aim to block the nerve proximal to this so as to ensure that both the anterior and posterior divisions are blocked. It is also important to follow the nerve proximally and distally to ensure that it is not a lymph node.4 Inguinal lymph nodes also appear hyperechoic and so can be confused with the nerve in short axis view. A nerve is a continuous structure and can be traced while a lymph node is not and can be seen only in a discrete location.5
    • Move your probe up and down and left to right, identifying the surrounding structures and their relationships.
    • Prepare the skin and assemble your needle/ syringe/ local anaesthetic. A 22g 50mm needle is usually adequate.
    • STOP BEFORE YOU BLOCK.
    • An In Plane, lateral to medial approach is preferred.
    • Advantages:7
      • Able to see the length of the needle and the needle tip during advancement.
      • As the nerve is lateral to other structures, it can usually be reached without accidental vascular puncture.
    • Disadvantages:7
      • Longer course through tissues, so a longer needle may be needed.
      • Less convenient for threading a catheter.
    • Pierce the needle through the skin on the lateral side of the probe and advance forward towards the femoral nerve. As the needle pierces the fascia iliaca, a “pop” sensation may be felt.
    • Aim to place the needle tip immediately adjacent to the lateral aspect of the femoral nerve, into the wedge-shaped tissue space lateral to the femoral artery.


    Figure 3. Needle placed into the wedge-shaped tissue space lateral to the femoral artery, lateral to the femoral nerve

    • Aspirate before injection. Inject the local anaesthetic in small aliquots with intermittent aspiration, observing the image for local anaesthetic spread and the patient for signs of discomfort (if awake) or toxicity.
    • Never inject against a high resistance—this may indicate intraneural needle placement.
    • Spread should be visualised below the fascia iliaca and ideally surrounding and highlighting the nerve (“doughnut sign”).


    Figure 4: Needle repositioned above the nerve, aiming to surround the femoral nerve with a “doughnut” of local anaesthetic

    • Due to contrast enhancement, the hyperechoic nerve often becomes more prominent after injection of hypoechoic local anaesthetic.

    Complications:

    • Infection
    • Vascular puncture and intravascular injection
    • Haematoma
    • Nerve injury, including intraneural injections

     

    References:

    1.    Marinković D, Simin J, Drasković B, Kvrgić I, Pandurov M. Efficiency of ultrasound guided lower limb peripheral nerve blocks in perioperative pain management for knee arthroscopy in children. A randomized study. Med Pregl. 2016;69(1-2):5-10.
    2.    Schloss BBhalla TKlingele KPhillips DPrestwich B, Tobias J. A retrospective review of femoral nerve block for postoperative analgesia after knee surgery in the pediatric population. J Pediatr Orthop. 2014;34(4):459-61
    3.    Turner A, Stevenson M, Cross K. Impact of ultrasound-guided femoral nerve blocks in the pediatric emergency department. Pediatr Emerg Care. 2014;30(4):227-9
    4.    Flack SAnderson C. Ultrasound guided lower extremity blocks. Paediatr Anaesth. 2012;22(1):72-80.
    5.    Szucs S, Morau D, Iohom G. Femoral nerve blockade. Med Ultrason. 2010;12(2):139-44.
    6.    Murray J, Derbyshire S, Shields M. Lower limb blocks. Anaesthesia. 2010;65(Suppl 1):57-66
    1. Jeyaraj S, Pepall T. Ultrasound guided femoral nerve block. Anaesthesia tutorial of the week 284. Available from: https://www.aagbi.org/sites/default/files/284%20Ultrasound%20Guided%20Femoral%20Nerve%20Block.pdf (accessed 10 May 2017)

     

    Subsartorial femoral

    Subsartorial (Adductor Canal Block)

    Dr Sanjay Desai

    Content

    Indications

    Anatomy

    Technique

    Volume of LA

    Specific Complications

    References

     

    Indications

    The subsartorial block is a largely motor sparing block, anaesthetising the femoral nerve after most of the motor branches to quadriceps have already exited, providing anaesthesia and analgesia intraoperatively and postoperatively for:

    Surgery to the anterior part of the knee e.g. Knee arthroscopy, Patellar surgery, ACL, MCL Reconstruction, Superficial surgery to the medial side of the leg.

    In conjunction with a popliteal block for all surgery below the site of insertion on the lower limb.

    Anatomy

    The femoral nerve passes through the femoral canal to lie beneath the sartorius muscle, entering an aponeurotic intermuscular tunnel in the middle third of the medial side of the thigh called the Subsartorial canal, Adductor canal or Hunter’s canal.

    The Adductor canal is bounded anterolaterally by vastus medialis, anteromedially by sartorius and posteriorly by adductor magnus.

    The Adductor canal contains the femoral artery, femoral vein, saphenous nerve, nerve to vastus medialis and the posterior branch of the obturator nerve (see Image 1).

    You can view the full article HERE.

    Image library

    usra_64

    Clinical training opportunities

    USGRA PAEDIATRIC INSTITUTIONS:

    Jackson Rees Department of Anaesthesia, Alder Hey Children’s NHS Foundation Trust Hospital, Liverpool, UK
    Self Funded

    1-12 month placements available

    Contact
    Dr Rishi Diwan
    Rishi.diwan@alderhey.nhs.uk