• Katherine Z Isoardi, Lachlan Parker, Keith Harris, Stephen Rashford, and Geoffrey K Isbister.
• Clinical Toxicology Unit, Princess Alexandra, Hospital, Brisbane, Australia; Clinical Toxicology Research Group, University of Newcastle, Newcastle, Australia; Faculty of Medicine, University of Queensland, Brisbane, Australia. Electronic address: katherine.isoardi@health.qld.gov.au.
• Ann Emerg Med. 2022 Aug 1; 80 (2): 120-126.

Study ObjectiveLarge doses of intramuscular (IM) naloxone are commonly used in out-of-hospital settings to reverse opioid toxicity; however, they are used less commonly in hospitals because of concerns about opioid withdrawal, particularly agitation. We aimed to determine the frequency of severe agitation following a single 1.6 mg IM naloxone dose.MethodsWe undertook a prospective study of adult (>15 years) patients treated by an Australian state ambulance service with 1.6 mg IM administration of naloxone for respiratory depression (respiratory rate <11 breaths/min and/or oxygen saturation <93% in room air) caused by presumed opioid poisoning. The primary outcome was the proportion of presentations with severe agitation (Sedation Assessment Tool score >1) within 1 hour of naloxone administration. Secondary outcomes were the proportion of presentations with acute opioid withdrawal (tachycardia [pulse rate >100 beats/min], hypertension [systolic >140 mm Hg], vomiting, agitation, seizure, myocardial infarction, arrhythmia, or pulmonary edema), and reversal of respiratory depression (respiratory rate >10 breaths/min and saturation >92% or Glasgow Coma Scale score 15).ResultsFrom October 2019 to July 2021, there were 197 presentations in 171 patients, with a median age of 41 years (range, 18 to 80 years); of the total patients, 119 were men (70%). The most common opioids were heroin (131 [66%]), oxycodone (14 [7%]), and morphine (11 [6%]). Severe agitation occurred in 14 (7% [95% confidence interval {CI} 4% to 12%]) presentations. Opioid withdrawal occurred in 76 presentations (39% [95% CI 32% to 46%]), most commonly in the form of tachycardia (18%), mild agitation/anxiety (18%) and hypertension (14%). Three presentations (1.5%) received chemical sedation for severe agitation within 1 hour of naloxone administration. A single 1.6 mg dose of naloxone reversed respiratory depression in 192 (97% [95% CI: 94% to 99%]) presentations.ConclusionSevere agitation was uncommon following the administration of 1.6 mg IM naloxone and rarely required chemical sedation.Copyright © 2022 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.

31 keywords...

hide…