Background Adequate pain relief in prehospital care is a major challenge in all acute traumas, especially for those with hip fractures, whose injuries are difficult to immobilise and whose long term outcomes may be adversely affected by administration of opiate analgesics. Fascia Iliaca Compartment Block (FICB) is routinely undertaken by clinicians in the emergency department for patients with hip fracture, but has not been fully evaluated for use by paramedics in prehospital care.

We aimed to test whether FICB for hip fracture pain relief carried out by paramedics in prehospital care was feasible, safe and acceptable, and whether trial Methods were viable, so that we could decide whether to proceed to a fully-powered RCT to evaluate clinical and cost effectiveness.

Methods Nineteen paramedics were trained to administer FICB. They randomly allocated eligible patients to FICB or usual care using audited scratchcards. Patients were followed up to assess availability of key outcomes including quality of life, length of hospital stay, pain scores, and adverse events. Findings were analysed against pre-specified feasibility criteria to determine whether it was appropriate to progress to a fully-powered trial.

Results Seventy-one patients were randomised by paramedics between 28/6/16 and 31/7/17; 57 of these patients consented to follow up. The only outcome which reached a statistically significant difference between groups was the proportion of participants who received morphine (38% difference between groups 95% CI −61.88 to −15.79). There was a difference of approximately nine days in the length of stay between trial arms (mean difference 9.12 (95% CI −20.51 to 2.27).

Conclusions RAPID met its pre-specified progression criteria; a funding application for a fully-powered RCT will therefore be submitted. We will consider the use of length of stay as the primary outcome measure, as feasibility study findings indicated that there was a difference between groups without reaching statistical significance.