MedWire News: A major audit of central neuraxial block (CNB) use in the UK’s National Health Service (NHS) has revealed a low incidence of major complications, two-thirds of which resolve within 6 months.
The audit, the results of which are published in the British Journal of Anaesthesia, was conducted by the Royal College of Anaesthetists, and covered a 2-week period at the end of September 2006. Participation in the audit was voluntary, but Tim Cook (Royal United Hospital, Bath, UK) and team report that all 309 NHS hospitals participated.
The researchers scaled up the data for the 2-week audit period to arrive at an annual total of 707,455 CNB procedures. Of these, 46% were subarachnoid blocks, 41% were epidurals, 6% were combined spinal–epidurals, and 7% were caudals. Most procedures were performed for obstetric (45%) or peri-operative (44%) purposes.
The hospitals reported 84 major complications over a 1-year period. Of all complications that were not immediately fatal, 41 caused initial neurologic impairment, but 61% of these patients had major improvement within 6 months. The team further analyzed 52 cases that within the audit time and potentially arising from CNB performed in an NHS hospital.
Twenty-two of these patients recovered completely within 6 months of injury. These patients had complications including epidural abscesses, nerve or spinal cord injuries, cardiovascular collapse, meningitis, and vertebral canal hematoma.
Thirty patients had “permanent” disabling injuries, defined as lasting for more 6 months, giving a rate of 4.2 per 100,000 CNB procedures. Permanent disability was not linked to CNB type, but 83% occurred in a peri-operative setting.
In 16 cases, however, the patients were either considered likely to make a good recovery or their condition was only tenuously linked to CNB. This gave an “optimistic” permanent disability rate of 2.0 per 100,000 procedures.
The pessimistic and optimistic rates of death or paraplegia were 1.8 and 0.7 per 100,000 procedures, respectively.
“By some distance, this is the largest reported prospective audit of complications occurring from CNB,” said Donal Buggy (Mater University Hospital, Dublin, Ireland) in an accompanying editorial.
“It provides a new, reliable resource which anesthesia doctors and patients can use to inform clinical decision-making and consent where CNB is involved, in the context of individual risk–benefit analysis.”
He added: “Although reassuring, it emphasizes the importance of an accessible, confidential reporting system for the serious adverse outcomes which may, extremely rarely, be associated with CNB, and the ongoing need for vigilance in peri-operative monitoring of these powerful techniques.”
