Prehospital Ketamine Administration for Excited Delirium with Illicit Substance Co-Ingestion and Subsequent Intubation in the Emergency Department.
Joshua J Solano, Lisa M Clayton, Daniel J Parks, Shayne E Polley, Patrick G Hughes, Charles H Hennekens, Richard D Shih, Scott M Alter
Prehospital and disaster medicine December 2021 DOI: 10.1017/s1049023x21000935 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Retrospective observational cohort study Peer reviewed |
|---|---|
| Sample size | 86 |
| Population | Patients aged 18 years or older who received prehospital intramuscular ketamine for excited delirium at two large community hospitals |
| Intervention | Ketamine |
| Duration | 28 months |
| Topics | Ketamine Esketamine |
| Keywords | Cocaine Excited delirium Intratracheal Intubation |
| Key findings | Patients treated with prehospital intramuscular ketamine for excited delirium who also had cocaine intoxication had a 5.75-fold higher rate of subsequent emergency department intubation (33% vs 8%; OR 5.75, 95% CI 1.57 to 21.05) than those without cocaine intoxication. No other substance tested showed a similar association with intubation. |
Abstract
Excited delirium, which has been defined as combativeness, agitation, and altered sensorium, requires immediate treatment in prehospital or emergency department (ED) settings for the safety of both patients and caregivers. Prehospital ketamine use is prevalent, although the evidence on safety and efficacy is limited. Many patients with excited delirium are intoxicated with illicit substances. This investigation explores whether patients treated with prehospital ketamine for excited delirium with concomitant substance intoxication have higher rates of subsequent intubation in the ED compared to those without confirmed substance usage. Over 28 months at two large community hospitals, all medical records were retrospectively searched for all patients age 18 years or greater with prehospital ketamine intramuscular (IM) administration for excited delirium and identified illicit and prescription substance co-ingestions. Trained abstractors collected demographic characteristics, history of present illness (HPI), urine drug screens (UDS), alcohol levels, and noted additional sedative administrations. Substance intoxication was determined by UDS and alcohol positivity or negativity, as well as physician HPI. Patients without toxicological testing or documentation of substance intoxication, or who may have tested positive due to ED sedation, were excluded from relevant analyses. Subsequent ED intubation was the primary pre-specified outcome. Odds ratios (OR) and 95% confidence intervals (CI) were calculated to compare variables. Among 86 patients given prehospital ketamine IM for excited delirium, baseline characteristics including age, ketamine dose, and body mass index were similar between those who did or did not undergo intubation. Men had higher intubation rates. Patients testing positive for alcohol, amphetamines, barbiturates, benzodiazepines, ecstasy, marijuana, opiates, and synthetic cathinones, both bath salts and flakka, had similar rates of intubation compared to those negative for these substances. Of 27 patients with excited delirium and concomitant cocaine intoxication, nine (33%) were intubated compared with four of 50 (8%) without cocaine intoxication, yielding a 5.75 OR (95%, CI 1.57 to 21.05; P = .009). Patients treated with ketamine IM for excited delirium with concomitant cocaine intoxication had a statistically significant 5.75-fold increased rate of subsequent intubation in the ED. Amongst other substances, no other trends with intubation were noted, but further study is warranted.
Comparable studies
Other observational and cohort studies on ketamine, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Taming the Ketamine Tiger Volunteers from a prison population | 2010 | Observational study | n = 20 |
| Increased spontaneous MEG signal diversity for psychoactive doses of ketamine, LSD and psilocybin Humans | 2017 | Observational study | |
| Disruption of Frontal–Parietal Communication by Ketamine, Propofol, and Sevoflurane Surgical patients undergoing induction of anesthesia with intravenous ketamine | 2013 | Observational cohort | n = 30 |
| Do the dissociative side effects of ketamine mediate its antidepressant effects? Treatment-resistant inpatients with major depressive disorder or bipolar disorder | 2014 | Observational cohort | n = 108 |
| Concomitant BDNF and sleep slow wave changes indicate ketamine-induced plasticity in major depressive disorder Patients with treatment-resistant major depressive disorder | 2012 | Observational cohort | n = 30 |
Citations in the library
Cited by 5
- Systematic review of parenteral ketamine for managing acute agitation in emergency settings. Asian Journal of Psychiatry 2025
- Ketamine: An emerging agent in the management of neuropsychiatric disorders. Asian Journal of Psychiatry April 1, 2025
- A Comparison of Ketamine to Midazolam for the Management of Acute Behavioral Disturbance in the Out-of-Hospital Setting. Annals of emergency medicine May 1, 2025
- Trends in new psychoactive substance poisonings in the Netherlands: A 14-year retrospective analysis (2012-2025). Addiction July 7, 2026
- Promises and Pitfalls of NMDA Receptor Antagonists in Treating Violent Aggression. Frontiers in Behavioral Neuroscience June 21, 2022