Ketamine versus benzodiazepines for severely agitated emergency department patients

Date First Published:
February 6, 2020
Last Updated:
August 27, 2020
Report by:
Kyle Saikaley, Resident Physician (McMaster University )
Search checked by:
Christine King, Casey MacKenzie , McMaster University
Three-Part Question:
In [severely agitated adult emergency department patients], does [ketamine] or [midazolam or lorazepam] [have a shorter time to sedation]?
Clinical Scenario:
A 25 year old male is brought into the emergency department by police profoundly agitated. You wonder whether ketamine will work faster than lorazepam or midazolam to treat the agitation.
Search Strategy:
Medline using the OVID interface.

(emergency department.mp. or Emergency Service, Hospital/ OR emergency room.mp. or Emergency Service, Hospital/ OR (accident and emergency).mp) AND (ketamine.mp. or Ketamine/ OR ketalar.mp. or Ketamine/) AND (benzodiazepines.mp. or Benzodiazepines/ OR versed.mp or Midazolam OR midazolam.mp. or Midazolam/ OR ativan.mp. or Lorazepam/ OR lorazepam.mp. or Lorazepam/)
Outcome:
165 papers found of which 163 irrelevant and 1 relevant that has not yet published results. The remaining paper is discussed below.
Relevant Paper(s):
Study Title Patient Group Study type (level of evidence) Outcomes Key results Study Weaknesses
Ketamine as a first-line treatment for severely agitated emergency department patients. Riddell J; Tran A; Bengiamin R; Hendey GW; Armenian P. 2017 USA 98 acutely agitated patients who required chemical sedation for acute agitation in ER. Ketamine (24) vs. Midazolam (17) vs. Lorazepam (33) vs. Haloperidol (14) vs. Combo (10) Prospective, observational study Time to adequate sedation Ketamine 6.57 mins vs. Midazolam 14.95 mins vs. Lorazepam 17.73 mins vs. Haloperidol 13.43 mins vs. Combo 23.30 mins (p<0.107) Single centre study, high proportion of methamphetamine abusers, not possible to randomize, physicians not blinded to
medications received, dosing was not uniform, small sample size
Author Commentary:
There are an abundance of pre-hospital studies that cover the use of ketamine as a treatment for severe agitation, but a paucity of studies covering it’s use in the emergency department. The only current study available that compares ketamine to benzodiazepines in the emergency department is non-randomized. There is an RCT currently in progress, with results not yet published.
Bottom Line:
There is insufficient robust evidence to recommend ketamine over midazolam or lorazepam for faster time to sedation in severely agitated emergency department patients. Further research on the topic is required before recommendations can be made.
References:
  1. Riddell J; Tran A; Bengiamin R; Hendey GW; Armenian P.. Ketamine as a first-line treatment for severely agitated emergency department patients.