Psychiatric Outcomes of Patients with Severe Agitation Following Administration of Prehospital Ketamine
Article Identification
- Title: “Psychiatric Outcomes of Patients With Severe Agitation Following Administration of Prehospital Ketamine”
- Authors: Jacob A. Lebin, MD, Arvin R. Akhavan, MD, et al.
- Journal: Academic Emergency Medicine
- Year: 2019
- Volume: 26
- Issue: 8
- Pages: 889-896
Quick Reference Summary
- In this retrospective cohort study of 141 encounters (59 receiving ketamine, 82 receiving benzodiazepines) for prehospital severe agitation, ketamine was not associated with a statistically significant increase in psychiatric inpatient admissions (p=0.23) or need for ED psychiatric evaluation.
- In patients with schizophrenia, ketamine did not significantly increase psychiatric admissions, suggesting no clinically meaningful exacerbation of underlying psychiatric disease compared to benzodiazepines during the emergency encounter.
Core Clinical Question
In adults requiring rapid sedation for severe prehospital agitation, does ketamine (intramuscular or intravenous) result in higher rates of psychiatric deterioration than benzodiazepine sedation?
Background
- Disease/Condition Overview: Acute severe agitation poses risks to both patients and clinicians in the prehospital and emergency setting. Rapid, safe sedation is often necessary.
- Prior Data on the Topic:
- Benzodiazepines and antipsychotics are traditional sedatives for agitation but can have delayed onset or respiratory side effects.
- Ketamine is a rapid-onset agent with some concerns regarding potential exacerbation of psychotic symptoms in patients with schizophrenia.
- Current Standard of Care: Most EMS protocols use benzodiazepines and/or antipsychotics to control agitation; ketamine is increasingly added for severe agitation or "excited delirium".
- Knowledge Gaps Addressed by Study:
- Potential effects of ketamine on psychiatric outcomes.
- Comparison of psychiatric outcomes between ketamine and established therapies.
Methods Summary
- Study Design: Retrospective cohort study.
- Setting and Time Period: Two urban academic medical centers, Jan 2014 - Jun 2016.
- Population Characteristics: Adults (≥18 years) with prehospital severe agitation requiring sedation.
- Exclusion Criteria: Sedation for other reasons, missing data, or non-participating hospital transport.
- Intervention Details: Ketamine administered intramuscularly or intravenously.
- Control/Comparison: Benzodiazepines, administered via various routes.
- Primary Outcome: Psychiatric inpatient admission.
- Statistical Analysis: Generalized estimating equations and Fisher’s exact tests.
Detailed Results
- Participant Flow: 173 encounters reviewed; 141 met eligibility (59 ketamine, 82 benzodiazepine).
- Primary Outcome: Psychiatric admission for ketamine group was 6.8%, benzodiazepine group was 2.4% (p=0.23).
- Secondary Outcomes: No significant increase in ED psychiatric evaluation or nonpsychiatric admissions with ketamine.
Results Table
| Outcome | Ketamine | Benzodiazepine | Difference (95% CI) | p-value |
|---|---|---|---|---|
| Psychiatric Admission | 6.8% | 2.4% | 4.3% | 0.23 |
| Nonpsychiatric Admission | 44.1% | 32.9% | 11.1% | 0.21 |
Authors' Conclusions
- Ketamine for severe prehospital agitation did not significantly increase psychiatric admissions or evaluations compared with benzodiazepines.
Critical Analysis
Strengths
- Large cohort size for evaluating psychiatric outcomes.
Limitations
- Retrospective design with possible selection bias.
Clinical Application
- Ketamine is a viable option for rapid sedation without the significant risk of psychiatric deterioration.
How To Use This Info In Practice
Consider using ketamine for severe agitation when rapid sedation is required, monitoring for any exacerbation of psychiatric conditions.