The study, the largest of its kind, looked at 19 228 transported adult patients in Ontario, Canada, and sought to identify factors that are associated with in-transit adverse events.
Female sex, traumatic injuries, cardiovascular disease, assisted ventilation or blood pressure instability and on-scene treatment were all associated with in transit critical events. Transport characteristics also varied with geography, with transports in northern Ontario having more surgical and medical cases with longer transport distances, while in southern Ontario helicopter calls for trauma patients were common.
Regarding women being more at risk of adverse events, "this observation may be attributable to differences in disease presentations, differential treatment or differences in referral patterns and transport requests between men and women," write Dr. Jeff Singh, University Health Network, Toronto and coauthors.
Many critical events were related to airway management and may have been avoided through preparation before transport.
They suggest their findings may help in refining protocols for air transport of patients at high-risk of in-transit resuscitation. It may also help in training paramedic transport crews and in preparing patients by hospital staff before transport.
"This data may provide insight for medical crew training regarding likely in-flight medical management scenarios, or markers for more robust stabilization of patients by hospital staff preparing patients for transport" writes Dr. Alex Isakov, Department of Emergency Medicine, Emory University in Atlanta, USA in a related commentary . "It may also help in the development of evidence-based criteria for dispatch."