Ketamine for Rapid Sedation of Agitated Patients in the Prehospital and Emergency Department Settings: A Systematic Review and Proportional Meta-Analysis

Abstract

Background: Rapid tranquilization of agitated patients can prevent injuries and expedite care. Whereas antipsychotics and benzodiazepines are commonly used for this purpose, ketamine has been suggested as an alternative.

Objective: The aim of this systematic review is to determine the safety and effectiveness of ketamine to sedate prehospital and emergency department (ED) patients with undifferentiated agitation.

Methods: Studies and case series of patients receiving ketamine for agitation were included. Studies were excluded if ketamine was used for analgesia, procedural sedation, asthma, or induction. Information sources included traditional and gray literature.

Results: The initial search yielded 1176 results from 14 databases. After review of titles and abstracts, 32 studies were reviewed and 18 were included in the analysis, representing 650 patient encounters. The mean dose of ketamine was 315 mg (SD 52) given intramuscularly, with adequate sedation achieved in 7.2 min (SD 6.2, range 2-500). Intubation occurred in 30.5% of patients (95% confidence interval [CI] 27.0-34.1%). In the majority of those patients, ketamine was administered by paramedics during ground transport and the patient was intubated on ED arrival. When ketamine was administered in the ED, the intubation rate was 1.8% (95% CI 0.0-4.4%); in air medical transport, the rate was 4.9% (95% CI 0.0-10.3%). Other reported side effects included: vomiting, 5.2% (2.3-8.1%); hypertension, 12.1% (5.7-18.6%); emergence reactions, 3.5% (1.4-5.6%); transient hypoxia, 1.8% (0.1-3.6%) and laryngospasm, 1.3% (0.3-2.3%).

Conclusions: Ketamine provides rapid sedation for undifferentiated agitated patients and is associated with higher intubation rates when used by ground Emergency Medical Services paramedics, compared with ED or air medical transport patients. Other side effects are common but usually self-limiting.

Keywords: acute behavioral disturbance (ABD); agitated; emergency department; excited delirium syndrome (ExDS); intubation; ketamine; laryngospasm; sedation.