Ketamine for Acute Pain in the ED: Mechanisms, Protocols, and Safety Considerations

Document Type : Review Article

Authors

1 Department of Pain Medicine, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran.

2 Department of Anesthesiology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran.

3 Department of Emergency Medicine, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran.

Abstract
Background: Acute pain is one of the most frequent presenting complaints in emergency departments (EDs). In the context of the global opioid crisis, there is increasing interest in effective non-opioid and opioid-sparing analgesic strategies. Ketamine, at subanesthetic doses, has emerged as a valuable option for acute pain management due to its unique pharmacologic profile.
Objectives: This narrative review aims to synthesize current evidence on the mechanisms of analgesia, clinical efficacy, dosing protocols, and safety considerations of ketamine for acute pain management in adult ED patients.
Methods: A comprehensive narrative review of the literature was conducted using recent randomized controlled trials, systematic reviews, meta-analyses, and international guidelines focusing on ketamine use for acute pain in emergency settings. Studies from diverse geographic regions and healthcare systems were included to provide a global perspective.
Results: Evidence consistently demonstrates that subdissociative-dose ketamine provides analgesia comparable to opioids for acute pain in the ED. Typical intravenous doses of 0.1–0.35 mg/kg, administered as a bolus or infusion, achieve rapid pain relief while preserving respiratory drive and airway reflexes. Ketamine is associated with higher rates of transient neuropsychiatric effects, such as dizziness and emergence reactions, but lower risks of respiratory depression compared with opioids. Alternative routes of administration, including intranasal and subcutaneous, offer additional flexibility in selected patients.
Conclusion: Ketamine is a safe and effective alternative or adjunct to opioids for acute pain management in the emergency department when used at appropriate subanesthetic doses. With proper patient selection, monitoring, and adherence to established protocols, ketamine can play a central role in multimodal ED analgesia strategies aimed at improving pain control while reducing opioid exposure.

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