Paediatric Regional Anaesthesia: Updates in Central Neuraxial Techniques and Thoracic and Abdominal Blocks
Highlights
- The conus medularis will extend to L4 in premature infants, L3 in a term neonate, but by 1 yr of age, it will be nearer its adult location of L1 (View Highlight)
- dural sac extends lower in premature babies and neonates (to around S4), whereas by age 2 yrs it has developed to its adult location at S2 (View Highlight)
- The absence of thoracic kyphosis in infants means greater cephalad spread of injected drugs, extending the dermatomal coverage of a central neuraxial block (View Highlight)
- The neonatal cerebrospinal fluid volume (4 ml kg−1) is twice that of adults (2 ml kg−1) (View Highlight)
- The vascularity of the pia mater combined with greater cardiac output leads to faster local anaesthetic (LA) reabsorption, and thus, shorter block duration (View Highlight)
- The immaturity of the sympathetic autonomic nervous system in infants means that the chemical sympathectomy of central neuraxial anaesthesia does not result in the vasoplegia, hypotension, or cardiovascular instability sometimes seen in adults. (View Highlight)
- Caudal blocks represent the most common form of regional anaesthesia in children with a low failure rate (1%); low complication rate (1.9%); and excellent safety profile consisting of cardiovascular or central nervous toxicity of 0.02% (View Highlight)
- The ASRA/ESRA recommends ropivacaine (0.2%) or levobupivacaine/bupivacaine (0.25%) in volumes not exceeding 1 ml kg−1 (View Highlight)
- The classic Armitage regimen of caudal dosing of bupivacaine 0.25% at 0.5 ml kg−1 for sacro-lumbar block, 1 ml kg−1 for abdominal block, and 1.2 ml kg−1 for mid-thoracic block is poorly predictive for cranial extension of LA (View Highlight)
- Pudendal-nerve-block success rates are reported >85% amongst consultants and non-consultants; however, this compares poorly to caudal success rates of 99% (View Highlight)