HEMS dispatch: A systematic review

Introduction Helicopter emergency medical services dispatch is a contentious issue in modern prehospital services. Whilst the link between helicopter emergency medical services and improved patient outcome is well evidenced, allocation to the most appropriate incidents remains problematic. It is unclear which model of deployment is the most efficient at targeting major trauma and whether this can be improved with a change in dispatch process. The objective of this study was to have an overview of the evidence for dispatch models of helicopter emergency medical services to critically ill or injured patients. Methods This systematic review was conducted in accordance with a protocol developed from the PRISMA guidelines. MEDLINE, Embase, CINAHL and the Cochrane library were searched focusing on keywords involving dispatch of helicopter emergency medical services resources. Results Ninety-seven articles were screened and 14 articles were eligible for inclusion. Most were of low quality, with three of moderate quality. Heterogeneity in the methodology of included articles precluded meta-analysis, so a narrative review was performed. Conclusions This review demonstrates the lack of evidence surrounding helicopter emergency medical services dispatch models. Whilst it is not possible to identify a method of dispatch that will optimize helicopter emergency medical services allocation, common themes within the literature indicate that helicopter emergency medical services use is region specific and dispatch criteria should be designed to match specific systems. Additionally, mechanism of injury as well as physiological data from scene was shown to be the most accurate indicator for helicopter emergency medical services attendance.