Prehospital Use of Ketamine in Mountain Rescue: A Survey of Emergency Physicians of a Single-Center Alpine Helicopter-Based Emergency Service

Abstract

Although ketamine use in emergency medicine is widespread, studies investigating prehospital use are scarce. Our goal was to assess the self-reported modalities of ketamine use, knowledge of contraindications, and occurrence of adverse events associated with its use by physicians through a prospective online survey. The survey was administered to physicians working for Air-Glaciers, a Swiss alpine helicopter-based emergency service, and was available between September 24 and November 23, 2018. We enrolled 39 participants (participation rate of 87%) in our study and collected data regarding their characteristics, methods of ketamine use, knowledge of contraindications, and encountered side effects linked to the administration of ketamine. We also included a clinical scenario to investigate an analgesic strategy. Ketamine was considered safe and judged irreplaceable by most physicians. The main reason for ketamine use was acute analgesia during painful procedures, such as manipulation of femur fractures. The doses of ketamine administered with or without fentanyl ranged from 0.2 to 0.7 mg·kg-1 intravenously. Most physicians reported using fentanyl and midazolam along with ketamine. The median dose of midazolam was 2 (interquartile range 1-2) mg for a 70-kg adult. Monitoring and oxygen administration were used infrequently. Hallucinations were the most common adverse events. Knowledge of ketamine contraindications was poor. Ketamine use was reported by mountain rescue physicians to be safe and useful for acute analgesia. Most physicians use fentanyl and midazolam along with ketamine. Adverse neuropsychiatric events were rare. Knowledge regarding contraindications to the administration of ketamine should be improved.