Prehospital ketamine use by paramedics in the Australian Capital Territory: A 12 month retrospective analysis.

OBJECTIVE: The aim of this study was to describe prehospital use of ketamine by ACT Ambulance Service, and frequency of endotracheal intubation.

METHODS: This was a retrospective study of patients receiving prehospital ketamine between 1 January and 31 December 2013. Episodes were identified from the prehospital electronic patient care records, then linkage to ED records at two receiving hospitals. Demographics, dose, indication and occasions of intubation were analysed.

RESULTS: A total of 163 episodes were identified; 10 of these were excluded because of lack of identifying data or missing records (age 1-97 years [mean: 43, standard deviation: 21.7], 56% men). Median total dose was 60 mg (interquartile range 70; 5-400 mg) in three doses (interquartile range 3; 1-14 mg). For patients with a weight recorded (63%), median dose was 0.73 mg/kg. Indications were analgesia 68%, agitation/combative 25%, rapid sequence intubation 5% and others 2%. A total of 26 patients were endotracheally intubated, 11 prehospital (seven as an intended rapid sequence intubation and four combative patients with return of spontaneous circulation) and 15 in the ED. Of ED intubations, 10 were trauma patients and five were drug ingestion related. Patients receiving ketamine for combativeness were more likely to be intubated than those receiving it for analgesia (25 vs 7.2%; odds ratio: 3.46; 95% confidence interval: 1.12, 10.71). In those with a weight recorded, the mg/kg dose was not associated with subsequent intubation.

CONCLUSIONS: Median dose for analgesia was comparable with other studies; dose for sedation was less than reported elsewhere. Intubation rate for patients receiving prehospital ketamine was 17%. Further study is recommended to assess the ED course of the non-intubated group of patients, and consideration should be given to non-weight-based methods of dose selection.