Litigation related to drug errors in anaesthesia: an analysis of claims against the NHS in England 1995-2007.

Ninety-three claims (total cost 4,915,450 pounds) filed under 'anaesthesia' in the NHS Litigation Authority database between 1995 and 2007, alleging patient harm directly by drug administration error or by an allergic reaction, were analysed. Alleged errors were categorised using systems employed by the National Coordinating Council for Medication Error Reporting and Prevention, the American Society of Anesthesiologists Closed Claims Project and the UK Health and Safety Executive. The severity of outcome in each claim was categorised using adapted National Patient Safety Agency definitions. Sixty-two claims involved alleged drug administration errors (total cost 4,283,677 pounds) and 15 resulted in severe harm or death. Half alleged the administration of the wrong drug, in most (16) a neuromuscular blocker. Of the claims alleging the wrong dose had been given (25), nine alleged opioid overdose including by neuraxial routes. The most frequently recorded adverse outcomes were awake paralysis (19 claims; total cost 182,347 pounds) and respiratory depression requiring intensive care treatment (13 claims; total cost 2,752,853 pounds). Thirty-one claims involved allergic reactions (total cost 631,773 pounds). In 20 claims, the patient allegedly received a drug to which they were known to be allergic (total cost 130,794 pounds). All claims in which it was possible to categorise the nature of the error involved human error. Fewer than half the claims appeared likely to have been preventable by an 'ideal double checking process'.