Objectives: The objective was to compare the occurrence of respiratory depression, adverse events, and recovery duration of propofol versus ketamine for use in procedural sedation in the emergency department (ED).
Methods: This was a randomized nonblinded prospective clinical trial of adult patients undergoing procedural sedation for painful procedures in the ED. Patients with pain before the procedure were treated with intravenous (IV) morphine sulfate until their pain was adequately treated at least 20 minutes before starting the procedure. Patients were randomized to receive either propofol 1 mg/kg IV followed by 0.5 mg/kg every 3 minutes as needed or ketamine 1.0 mg/kg IV followed by 0.5 mg/kg every 3 minutes as needed. Doses, vital signs, nasal end-tidal CO2 (ETCO2), and pulse oximetry were recorded. Subclinical respiratory depression was defined as a change in ETCO2 of >10 mm Hg, an oxygen saturation of <92% at any time, or an absent ETCO2 waveform at any time. Clinical interventions related to respiratory depression were noted during the procedure, including the addition of or increase in the flow rate of supplemental oxygen, the use of a bag-valve mask apparatus, airway repositioning, or stimulation to induce breathing. After the procedure, patients were asked if they experienced pain during the procedure and had recall of the procedure. Physicians were asked to describe any adverse events or the occurrence of recovery agitation.
Results: One-hundred patients were enrolled; 97 underwent sedation and were included in the analysis. Fifty patients received propofol and 47 received ketamine. Subclinical respiratory depression was seen in 20 of 50 patients in the propofol group and 30 of 47 patients in the ketamine group (p = 0.019, effect size 22.8%; 95% CI = 4.0% to 43.6%). Clinical interventions related to respiratory depression were used in 26 of 50 propofol patients and 19 of 47 ketamine patients (p = 0.253, effect size = −13.7%; 95% CI = −33.8% to 6.4%). The median times of the procedures were 11 minutes (range = 4 to 33 minutes) for the ketamine group versus 10 minutes (range = 5 to 33 minutes) for the propofol group (p = 0.256). The median time to return to baseline mental status after the procedure was completed was 14 minutes (range = 2 to 47 minutes) for the ketamine group and 5 minutes (range = 1 to 32 minutes) for the propofol group (p < 0.001). Pain during the procedure was reported by 3 of 50 patients in the propofol group and 1 of 47 patients in the ketamine group (effect size = −3.9%, 95% confidence interval [CI] = −11.9 to 4.1). Recall of some part of the procedure was reported by 4 of 50 patients in the propofol group and 6 of 47 patients in the ketamine group (effect size = 4.8%, 95% CI = −7.6% to 17.1%). Forty-eight of 50 procedures were successful in the propofol group and 43 of 47 in the ketamine group (p = 0.357, effect size = 0.3%; 95% CI = −7.8% to 8.4%). Recovery agitation was reported in 4 of 50 in the propofol group and 17 of 47 in the ketamine group (effect size = 28.2%, 95% CI = 12.4% to 43.9%).
Conclusions: This study detected a higher rate of subclinical respiratory depression in patients in the ketamine group than the propofol group. There was no difference in the rate of clinical interventions related to respiratory depression, pain, or recall of the procedure between the groups. Recovery agitation was seen more frequently in patients receiving ketamine than in those receiving propofol. The time to regain baseline mental status was longer in the ketamine group than the propofol group. This study suggests that the use of either ketamine or propofol is safe and effective for procedural sedation in the ED.
ACADEMIC EMERGENCY MEDICINE 2010; 17:604–611 © 2010 by the Society for Academic Emergency Medicine