The Administration of Prehospital Ketamine for Chemical Restraint Does Not Prolong On-Scene Times Compared to Haloperidol Based Sedation

Agitated patients who present a danger to themselves or emergency medical services (EMS) providers may require chemical restraints.  Haloperidol is employed for chemical restraint in many EMS services.  Recently, ketamine has been introduced as an alternate option for prehospital sedation.  On-scene time is a unique metric in prehospital medicine which has been linked to outcomes in multiple patient populations. When used for chemical restraint, the impact of ketamine relative to haloperidol on on-scene time is unknown. Objective: To evaluate whether the use of ketamine for chemical restraint was associated with a clinically significant (≥5 minute) increased on-scene time compared to a haloperidol based regimen. Methods Patients who received haloperidol or ketamine for chemical restraint were identified by retrospective chart review.  On-scene time was compared between groups using an unadjusted Student t-test powered to 80% to detect a ≥5 minute difference in on-scene time. Results 110 cases were abstracted (Haloperidol = 55; Ketamine = 55). Of the patients receiving haloperidol, 11/55 (20%) were co-administered a benzodiazepine, 4/55 (7%) received diphenhydramine and 34/55 (62%) received the three drugs in combination. There were no demographic differences between the haloperidol and ketamine groups.  On-scene time was not statistically different for patients receiving a haloperidol based regimen compared to ketamine (18.2 minutes, [95% CI 15.7-20.8] vs. 17.6 minutes, [95% CI 15.1-20.0]; p = 0.71). Conclusions The use of prehospital ketamine for chemical restraint was not associated with a clinically significant (≥5 minute) increased on-scene time compared to a haloperidol based regimen.