Prehospital analgesia in adults using inhaled methoxyflurane: a feasibility study

Protocol compliance was high (95%) (92/97), and post-treatment pain scores were documented in 90% (83/92) of cases. Median pain decreased from 8/10 pre-treatment to 5/10 post-treatment. Side effects occurred in 23% of patients, were mostly mild, and no serious methoxyflurane-related adverse events were observed.</p> <p>The results of this feasibility study were used to inform the deployment of an ongoing prospective stepped-wedge open-label, cluster randomized trial to inform clinical care in the real world.</p> <p><a target="_blank" href="clinicaltrials.gov">www.clinicaltrials.gov</a> identifier is NCT04287803</p> <p><b>Why was this study done?</b></p> <p>Pain is a common reason people call an ambulance, but providing fast and effective pain relief in the prehospital setting can be challenging.

Methoxyflurane is a self-administered inhaled pain medication that has been used internationally for many years, but its use within Canadian paramedic systems had not previously been evaluated.</p> <p><b>What did we do?</b></p> <p>We conducted a feasibility study with a Canadian paramedic service to determine whether a larger clinical trial of methoxyflurane could be successfully carried out. We examined how long it took to obtain approvals, how well paramedics followed the study protocol, and how completely important study data were collected.

We also described pain score documentation and monitored patients for side effects and adverse events.</p> <p><b>What did we find?</b></p> <p>A total of 92 patients with traumatic injuries received methoxyflurane. Paramedics followed study procedures in most cases, and post-treatment pain scores were documented for over 90% of patients. The most common side effects were dizziness, headache, and drowsiness.

No serious methoxyflurane-related adverse events were identified during the study. Although some operational and regulatory challenges delayed implementation, these challenges provided important lessons for future research.</p> <p><b>What do these findings mean?</b></p> <p>This study demonstrated that conducting a larger trial of methoxyflurane in Canadian paramedic services is feasible. The findings helped improve study procedures, training, and operational planning and directly informed the design and launch of an ongoing multicentre trial evaluating methoxyflurane for the treatment of traumatic pain in the prehospital setting.</p>