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

Fig. 3
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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