Combination of ketamine and propofol versus either agent alone for procedural sedation in the emergency department

Purpose. The safety of using ketamine- propofol combinations as an alternative to using either agent alone for procedural sedation is discussed. Drs. Thomas, Jennett-Reznek, and Patanwala are members of the Section Advisory Group on Emergency Medicine for the American Society of Health-System Pharmacists Section of Clinical Specialists and Scientists. Summary. A total of 10 trials comparing the combination of ketamine and propofol with either agent alone for procedural sedation in the emergency department were examined. The evidence reviewed suggests that combining these agents may help to minimize adverse effects such as hypotension and respiratory depression. Ketamine is not commonly used as a single agent in adults because of the risk for emergence reactions; however, when combined with propofol, no significant increase in this adverse effect was found compared with propofol monotherapy. Administering ketamine and propofol can be accomplished by using a two-syringe technique or combining both medications into a single syringe. When two syringes are used, a ketamine 0.3-0.5-mg/kg i.v. bolus dose is administered, followed by a propofol 0.4-1-mg/kg i.v. bolus dose. Sedation is maintained with intermittent i.v. boluses of propofol 0.1-0.5 mg/kg. A 1:1 ratio of ketamine and propofol can also be combined into a single syringe by using the same concentration (10 mg/mL) and equal volumes of each drug, yielding a final concentration of 5 mg/mL for each component. Conclusion. The combined use of ketamine and propofol is a reasonable alternative to propofol alone for procedural sedation in patients at higher risk for respiratory depression or hypotension. Use of the combination requires the development of standardized protocols for drug preparation and dosage to minimize the potential for errors.