Ketamine for Acute Pain Management in the Emergency Department

Abstract

Introduction: Ketamine is increasingly used for acute pain in emergency settings as an opioid alternative, but optimal dosing and adverse effect profiles are debated. This review assesses efficacy and safety of sub-dissociative ketamine.
Methods: Literature review (2015–2024) of RCTs comparing intravenous ketamine (0.1–0.3 mg/kg) to morphine or placebo for acute moderate-to-severe pain in adults. Primary outcome: pain reduction (NRS/VAS) at 30 minutes. Secondary: rescue analgesia and psychoperceptual side effects.
Results: Fourteen RCTs (n=1,872) showed ketamine reduced pain scores similarly to morphine (mean difference −0.4/10, p=0.45) at 30 minutes. Ketamine had lower incidence of respiratory depression (0% vs. 2%, p=0.02) but higher dizziness (18% vs. 8%) and mild dissociation (12% vs. 0%). Rescue analgesia need was similar.
Discussion: Sub-dissociative ketamine provides non-inferior analgesia to opioids with a favorable respiratory safety profile. Mild psychoperceptual effects are transient and rarely require treatment.
Conclusions: Low-dose ketamine is an effective and safe alternative or adjunct to opioids for acute pain in the ED, especially when respiratory compromise is a concern.