Anaesthesia: Central neuraxial block producing neurological injury

Regarding central neuraxial blocks, which one of the following is MOST likely to cause permanent neurological injury?

a) An epidural sited for obstetric indications

b) An epidural sited for adult general surgical indications

c) An epidural sited for paediatric general surgical indications

d) A spinal sited rather than an epidural

e) An epidural sited for chronic pain indications

Answer: b

In 2009, the ‘NAP3’ study was published on the website of the Royal College of

Anaesthetists. It is an impressive body of work that has given a numerator and denominator

for injury following central neuraxial blocks (CNB). To ascertain the denominator

they estimated the total number of CNB performed in a year by looking at a two-week

snapshot. All of the units using epidurals in the UK returned information for the snapshot

and a denominator figure of just over 700 000CNBs per year was found. Potential

cases of permanent neurological injury following CNB were reported and reviewed to

determine the likelihood of the injury being due to the CNB. This allowed the reporters

to attach an optimistic figure (in which only the highly likely to be due to the CNB

were included) and a pessimistic figure (in which some of the more tenuous associations

between CNB and injury were included). The findings showed that the risk was

generally lower than people had previously thought. Epidurals caused more harm

than spinals (6.1 vs. 2.2 cases per 100 000 for the ‘pessimistic’ interpretation) and the

highest risk group for epidurals was in adult general peri-operative care. This was

probably due to the high incidence of sicker patients having thoracic epidurals on a

background of pharmacological or pathological derangement of their clotting cascade.

Royal College of Anaesthetists. Major complications of central neuraxial block in the

United Kingdom. Report and findings of the 3rd National Audit Project of the Royal

College of Anaesthetists. London: RCA, 2009. Online at www.rcoa.ac.uk/docs/

NAP3_web-large.pdf (Accessed 30 October 2009)

Anaesthesia