Impact of Ketamine Use on Adjunctive Analgesic and Sedative Medications in Critically Ill Trauma Patients

BACKGROUND Ketamine may be used to manage pain and agitation that is refractory to what are usually considered traditional agents such as fentanyl, propofol, benzodiazepines, and dexmedetomidine; however, literature describing the use of ketamine continuous infusions for this purpose in critically ill trauma patients is limited. OBJECTIVES The primary objective of this study was to determine the impact of the initiation of a ketamine continuous infusion on sedative and analgesic use in critically ill trauma patients. Secondary objectives were to identify the patient population in which ketamine was initiated, assess the proportion of time patients were at their goal level of sedation, and determine the dosing patterns of adjunctive sedative agents. METHODS This single-center retrospective chart review over a 19-month period included critically ill mechanically ventilated adult trauma patients in whom a ketamine continuous infusion was initiated for management of sedation and agitation. Patients who received ketamine for other indications or by the acute pain management service were not included in this evaluation. RESULTS Thirty-six patients were included in the study. Patients in whom ketamine was initiated tended to be white men with blunt trauma. Overall, the initiation of ketamine was associated with a decrease in the amount of opioids and propofol used and an increase in the amount of ziprasidone and dexmedetomidine needed to achieve the goal Richmond Agitation Sedation Score. When compared with the time period before ketamine initiation, the proportion of time that patients achieved goal sedation was not significantly different after the addition of ketamine. CONCLUSIONS Although the use of ketamine in critically ill mechanically ventilated adult trauma patients was associated with decreased opioid use, it was also associated with increased use of dexmedetomidine and ziprasidone to achieve and maintain sedation. Further examination of clinical outcomes associated with these differences in drug use in a larger population of trauma patients is warranted before routine use of ketamine for analgesia and sedation can be recommended.