Audit of the safety and effectiveness of ketamine for procedural sedation in the emergency department.

AIM To examine the effectiveness and safety of the sedative agents used in the emergency department following the introduction of ketamine as an agent for procedural sedation METHODS A 2-year prospective audit of sedation practice was undertaken. This specifically examined the rationale behind a doctor's choice of sedative agent, the depth of sedation achieved, adverse events and the time taken to regain full orientation. RESULTS 210 patients were included of whom 85 (40%) were given ketamine, 107 (51%) midazolam and 18 (9%) propofol. The median time to full orientation was 25 min for ketamine, 30 min for midazolam and 10 min for propofol. Complications occurred in 15.9% of sedations overall (14.6% of those given ketamine, 15.8% given midazolam and 22.2% given propofol). Apnoea and hypoxia most often occurred with midazolam and propofol, while hypertension and hypertonicity were encountered more frequently with ketamine. In addition, 19.5% of patients given ketamine suffered the re-emergence phenomenon. The association between deep sedation with no response to pain and adverse events encountered with midazolam does not occur with ketamine. CONCLUSIONS Ketamine is both safe and effective and compares favourably with midazolam as an agent for procedural sedation in the emergency department. Although the re-emergence phenomenon occurred, no psychological sequelae were encountered after return to full orientation. Ketamine may be particularly useful in groups of patients at high risk of adverse effects with midazolam.