Ambient air carbon monoxide pre-hospital screening: a cohort study

Objectives The Carbon Monoxide Prehospital Screening Study sought to evidence whether carbon monoxide (CO) screening should be a routine observation within UK ambulance services. Methods Using ambient air CO monitors worn by ambulance clinicians in the East of England, this prospective cohort study aimed identified the number of patients exposed to CO (>5 parts per million) in an emergency ambulance population, to inform the social and clinical presentation of CO exposed patients, particularly following low-level exposure. Subsequently the experiences of CO exposed patients and ambulance clinician views about pre-hospital CO screening were sought. Results During October 2015 to September 2016 six CO monitor activations were recorded among 15,000 patient incidents. None were suspected CO incidents at the point of the ambulance call. The environments included homes, a multi-occupancy care home and the workplace. COPS findings indicated that ambulance clinicians were more frequently exposed to CO, apparently from vehicle exhaust fumes during their working day. No CO exposed patients consented to interview, but staff interviews revealed views about CO training, and CO monitor usage. Conclusion An incidence density of 4 patients per 10,000 incidents attended, were exposed to CO at levels which would not have been suspected at the point of the 999 ambulance call. Ambulance clinicians would appreciate greater awareness of CO, and supported the case for prehospital CO monitoring.