Canadian paramedic experience with intramuscular ketamine for extreme agitation: A quality improvement initiative


excited delirium
emergency medical services

How to Cite

Helmer J, Acker J, Deakin J, Johnston T. Canadian paramedic experience with intramuscular ketamine for extreme agitation: A quality improvement initiative. Australasian Journal of Paramedicine [Internet]. 2020Apr.27 [cited 2023Jan.31];17. Available from:



There are no published reports in Canada examining paramedic use of ketamine for highly agitated patients or excited delirium syndrome. We employed a Plan, Do, Study, Act (PDSA) quality improvement approach to evaluate the safety and effectiveness of advanced care paramedic administered intramuscular (IM) ketamine for patients with extreme agitation in the out-of-hospital setting.


Data were prospectively collected from July 2018 to January 2019 when advanced care paramedics with specific training administered IM ketamine as an alternative to midazolam. Paramedics used a clinical audit form to document the ketamine dose, patient response on the Richmond Agitation Sedation Scale (RASS) at time intervals, adverse effects, and any airway management interventions they performed.


Thirty-three patients received either 4 mg/kg or 5 mg/kg of ketamine. Combining data for both doses, the median change in RASS score at 5 minutes post-ketamine was 3 (range 0 to 8) and statistically significant for each dose. There were seven cases (21%) with reported adverse effects including SpO2 <90% (3/7), hypersalivation (3/7), trismus or teeth grinding (2/7), muscular rigidity (1/7) and laryngospasm (1/7). Statistical analysis confirmed that the incidence of adverse events was not dose dependent. Basic airway management was performed in one-third of all cases.


We piloted the implementation of ketamine for sedation in our paramedic system by employing a PDSA cycle. Ketamine 5 mg/kg IM provided effective control of acutely agitated patients with adequate sedation at 5 minutes post-delivery. Any adverse events that occurred as a result of IM ketamine were readily managed with basic airway management interventions.


Cole J, Driver B, Klein L, et al. In reply: Ketamine is an important therapy for prehospital agitation. Its exact role and side effect profile are still undefined. Am J Emerg Med 2018;36:502-3.

Cole JB, Moore JC, Nystrom PC, et al. A prospective study of ketamine versus haloperidol for severe prehospital agitation. Clin Toxicol 2016;54:556-62.

Gonin P, Beysard N, Yersin B, Carron PN. Excited delirium: a systematic review. Acad Emerg Med 2018;25:552-65.

Scaggs TR, Glass DM, Hutchcraft MG, Weir WB. Prehospital ketamine is a safe and effective treatment for excited delirium in a community hospital based EMS system. Prehosp Disaster Med 2016;31:563-9.

Vilke GM, Debard ML, Chan TC, et al. Excited Delirium Syndrome (ExDS): defining based on a review of the literature. J Emerg Med 2012;43:897-905.

Campeau AG. The space-control theory of paramedic scene-management. Symb Interact 2008;31:285-302.

Maguire BJ, O’ Meara PF, Brightwell RF, O’ Neill BJ, Fitzgerald GJ. Occupational injury risk among Australian paramedics: an analysis of national data. Med J Aust 2014;200:477-80.

British Columbia Emergency Health Services. (2019). BCEHS Treatment Guidelines. Available at:

Hall RI, Sandham D, Cardinal P, et al. Propofol vs midazolam for ICU sedation. Chest 2001;119:1151-9.

Pfizer. Product Monograph. Midazolam Injection USP 2020. Available at:

Riddell J, Tran A, Bengiamin R, Hendey GW, Armenian P. Ketamine as a first-line treatment for severely agitated emergency department patients. Am J Emerg Med 2017;35:1000-4.

Chan EW, Taylor DM, Knott JC, et al. Intravenous droperidol or olanzapine as an adjunct to midazolam for the acutely agitated patient: a multicenter, randomized, double-blind, placebo-controlled clinical trial. Ann Emerg Med 2013;61:72.

Knott JC, Taylor DM, Castle DJ. Randomized clinical trial comparing intravenous midazolam and droperidol for sedation of the acutely agitated patient in the emergency department. ibid. 2006;47:61-7.

Isenberg D, Jacobs D. Prehospital agitation and sedation trial (PhAST): a randomized control trial of intramuscular haloperidol versus intramuscular midazolam for the sedation of the agitated or violent patient in the prehospital environment. Prehosp Disaster Med 2015;30:491-5.

Horton C. Prehospital use of ketamine for agitated patients. NEJM Journal Watch Emergency Medicine 2014. Available at:

Scheppke KA, Braghiroli J, Shalaby M, Chait R. Prehospital use of IM ketamine for sedation of violent and agitated patients. West J Emerg Med 2014;15:736-41.

Olives T, Nystrom P, Cole J, Dodd K, Ho J. Intubation of profoundly agitated patients treated with prehospital ketamine. Prehosp Disaster Med 2016;31:593-602.

Sibley A, Mackenzie M, Bawden J, et al. A prospective review of the use of ketamine to facilitate endotracheal intubation in the helicopter emergency medical services (HEMS) setting. Emerg Med J 2011;28:521.

Linder LM, Ross CA, Weant KA. Ketamine for the acute management of excited delirium and agitation in the prehospital setting. Pharmacotherapy 2018;38:138-51.

McKay WP. Intravenous analgesia for out-of-hospital traumatic pain in adults: Ketamine gives a greater reduction in pain than morphine but causes more adverse effects. Evid Based Nurs 2013;16:58.

Andolfatto G, Innes K, Dick W, et al. Prehospital analgesia with intranasal ketamine (PAIN-K): a randomized double-blind trial in adults. Ann Emerg Med 2019;74:241-50.

Buckland D, Crowe R, Cash R, et al. Ketamine in the prehospital environment: a national survey of paramedics in the United States. Prehosp Disaster Med 2018;33:23-8.

Mankowitz SL, Regenberg P, Kaldan J, Cole JB. Ketamine for rapid sedation of agitated patients in the prehospital and emergency separtment settings: a systematic review and proportional meta-analysis. J Emerg Med 2018;55:670-81.

Gangathimmaiah V, Le Cong M, Wilson M, et al. Ketamine sedation for patients with acute behavioral disturbance during aeromedical retrieval: a retrospective chart review. Air Med J 2017;36:311-4.

Hollis GJ, Keene TM, Ardlie RM, Caldicott DG, Stapleton SG. Prehospital ketamine use by paramedics in the Australian Capital Territory: a 12 month retrospective analysis. Emerg Med Australas 2017;29:89-95.

New South Wales Ambulance Service. NSWAS Protocol and Pharmacology Sydney, Australia 2019. Available at:

Ambulance Victoria. Clinical Practice Guidelines 2020. Available at:

Keseg D, Cortez E, Rund D, Caterino J. The use of prehospital ketamine for control of agitation in a metropolitan firefighter-based EMS system. Prehosp Emerg Care 2015;19:110-5.

Speroff TT, Oʼconnor TG. Study designs for PDSA quality improvement research. Qual Manag Health Care 2004;13:17-32.

BC Emergency Health Services. (2019). Fact Sheets and FAQs. Available at:

Sessler CN, Gosnell MS, Grap MJ, et al. The Richmond Agitation-Sedation Scale. Am J Respir Crit Care Med 2002;166:1338-44.

Kovacs G, Law A. Airway Intervention and Management in Emergencies (AIME) 2019. Available at:

Williams B, Boyle M, O’Meara P. Can undergraduate paramedic and nursing students accurately estimate patient age and weight? Prehosp Disaster Med 2010;25:171-7.

Lieb N, Gluckman WA. Accuracy of adult patient weight estimation by EMS providers. Prehosp Emerg Care 2004;8:96-7.

Martin DR, Soria DM, Brown CG, et al. Agreement between paramedic-estimated weights and subsequent hospital measurements in adults with out-of-hospital cardiac arrest. Prehosp Disaster Med 1994;9:54.

Burnett AM, Salzman JG, Griffith KR, Kroeger B, Frascone RJ. The emergency department experience with prehospital ketamine: a case Series of 13 patients. Prehosp Emerg Care 2012;16:553-9.