Ketamine and procedural success

There is a myth that increased muscular tone caused by ketamine leads to an increased failure rate of joint manipulations when this agent is used for procedural sedation in the ED. This is neither borne out by the published evidence nor our own experience of a series of cases, which have been presented by Louisa Chan at a former (UK) College of Emergency Medicine Conference. At the Australasian College of Emergency Medicine Annual Scientific Conference in Melbourne these data were presented by A/Professor Taylor’s team in Victoria, which provide evidence that procedural failure rate is in fact lower with ketamine than with other commonly used sedatives. Here is the abstract reproduced with the kind permission of A/Prof Taylor:
Failure to successfully complete a procedure following emergency department sedation
DMcD Taylor1,2 for the Emergency Department Sedation Study Investigators
1Austin Health; 2University of Melbourne, Melbourne, Australia
Aims: To determine the nature and incidence of, and factors contributing to, failure to successfully complete a procedure fol- lowing sedation in the ED
Methods: Eleven Australian ED enrolled consecutive adult and paediatric patients between January 2006 and December 2008. Patients were included if a sedative drug was administered for an ED procedure. Data collection was prospective and employed a specifically designed form.
Results: Two thousand six hundred and twenty three patients were enrolled (60.3% male, mean age 39.2 years). Failure to successfully complete the procedure occurred in 148 (5.6%) cases. Most failures occurred with attempted reductions of fractured/dislocated shoulders (35 cases), hips (32), ankles (21) and elbows (14). However, failure rates were highest among fractured/dislocated hips (18.5%), digits (13.7%), femurs (11.1%), mandibles (10.2%) and elbows (9.3%). Failure rates for residents/registrars (5.9%), consultants (5.6%) and nurse practitioners (5.9%) did not differ (P = 0.92). Overall, failure rates for the various drugs (used alone or in combina- tion) did not differ (P = 0.07). However, ketamine (used alone or in combination) was associated with a much lower failure rate (2.9%) than all other sedation drugs used (midazolam 5.8%, propofol 6.5%, fentanyl 6.9%, nitrous oxide 7.1%, and morphine 7.8%).
Conclusion: Procedural failure is uncommon although some pro- cedures are at higher risk, especially dislocated hip reduction. Failure rates do not appear to be affected by the designation of the operator or the sedative drug used. However, ketamine use is associated with lower failure rates. For those procedures at higher risk of failure, the provision of optimal conditions (spe- cialist unit assistance, venue, drug selection) may minimise failure rates.
Emergency Medicine Australasia 2010;22(S1):A52-3