Background Continuous positive airway pressure (CPAP) is not in widespread use in UK ambulance services, but could benefit patients with acute respiratory failure (ARF). As a new treatment in this context, clinician acceptability is an important factor in the feasibility of conducting definitive research in the prehospital arena.

Methods As part of a pilot randomised controlled trial (the ACUTE study), nine trial-trained paramedics took part in three semi-structured focus groups. 204 trained staff had been given the opportunity to take part. The sample included six staff who had recruited to the trial, one who had not, and two who had withdrawn from it. Audio-recordings were transcribed and analysed thematically.

Results Participants described facilitators to trial participation including: clear eligibility criteria and patient documentation, access to demonstration equipment, training away from the work environment, and repeated patient recruitment. Barriers to taking part included: the lack of protected time for training, inadequate workplace facilities for the electronic learning package used, adverse responses by receiving hospital staff, and infrequent patient exposure. Both paramedics who withdrew cited the inconvenience of carrying packs each shift. Some participants described anxiety and distress when opening packs to find a standard-care mask, and reported patients having similar reactions.

Conclusions Future researchers could promote improved workplace computing facilities and increased provision of face-to-face training days, which were praised by participants in these focus groups, but limited to a single event distant from some staff. Greater stakeholder engagement by researchers could reduce the difficulties at hospital handover reported by some ambulance staff. Where blinding is not possible, the perceptions of clinicians and patients should be considered carefully, as this study shows both may have adverse emotional responses to being treated with standard care, particularly when prospective consent discussions describe the trial intervention as potentially beneficial.