Ketamine has been rarely described for use in critically ill patients. We describe our institutional experience using continuous infusion ketamine for sedation. This was a retrospective chart review of patients admitted to the medical intensive care units (MICUs). An informatics query of patients who received continuous infusion ketamine between 1/1/2010 and 7/1/2012 was conducted. Mechanically ventilated patients in the MICU who received continuous infusion ketamine were included. Twelve patients met criteria. Mean age was 41; 60% were Caucasian and 60% were female. Six patients were admitted for pneumonia, three for asthma exacerbation. Median duration of ketamine therapy was 1.57 days. Median minimum and maximum rates were 0.24mg/kg/hr and 0.83mg/kg/hr. The maximum documented dose used was 2.8mg/kg/hr. The ketamine infusion was discontinued secondary to tachycardia or hypertension in two patients. No patient who received concomitant benzodiazepines experienced hemodynamic changes prompting ketamine cessation. Median maximum SBP, DBP, and HR while on ketamine were 154, 96 and 121, respectively. No further adverse events were identified. Five of the patients had decreases in concomitant sedative and analgesic doses while five had increases. Continuous infusion ketamine can safely be used for adjunctive sedation/analgesia in mechanically ventilated MICU patients. Larger trials are needed to further define optimal dosing and confirm safety.
Author(s): Craig B. Whitman, PharmD, Heather M. Rhodes, PharmD, Bethany R. Tellor, PharmD, and Nicholas B. Hampton, PharmD