A prospective study of ketamine as primary therapy for prehospital profound agitation

Abstract Objective We investigated the effectiveness of ketamine as a primary therapy for prehospital profound agitation. Methods This was a prospective observational study of patients receiving 5 mg/kg of intramuscular ketamine for profound agitation, defined as a score of + 4 on the Altered Mental Status Scale (AMSS), a validated ordinal scale of agitation from − 4 (unresponsive) to + 4 (most agitated). The primary outcome was time to adequate sedation (AMSS  Results Forty-nine patients were enrolled. Median age was 29 years (range 18–66); 76% (37/49) were male. Median time to adequate sedation was 4.2 min (95% CI: 2.5–5.9, range 1–25 min) and 90% (44/49) had adequate sedation prehospital. Seven patients (14%) received a second sedative prehospital. Intubation occurred in 57% (28/49) of patients. Mechanical ventilation lasted Conclusions In patients with prehospital profound agitation, ketamine provides rapid effective sedation when used as a primary therapy. Intubation was common but accompanied by a short duration of mechanical ventilation and appears to have been subject to individual physician practice variation.