Helicopter Emergency Medical Services Literature 2014 to 2016: Lessons and Perspectives, Part 2-Nontrauma Transports and General Issues

Establishing Outcome Parameters for Helicopter Emergency Medical Services Research in the Netherlands: Results of a Mixed-Methods Delphi Consensus Study

OBJECTIVES

Physician staffed Helicopter Emergency Medical Services (P-HEMS) care in the Netherlands has transitioned from predominantly trauma management to handling a variety of medical conditions. Relevant outcome parameters for Dutch P-HEMS research have not been previously defined. National consensus was sought to identify relevant long term patient outcome parameters, process outcome parameters and performance outcome parameters for Dutch P-HEMS care.

METHODS

This was a mixed methods Delphi consensus study. A list of potentially relevant outcome parameters was identified using a systematic literature review. These parameters were subsequently surveyed in a Delphi consensus study. Helicopter Emergency Medical Services physicians and relevant stakeholders were invited to participate in this Delphi survey, where they were allowed to suggest additional outcome parameters. Descriptive analysis was performed on all data sets.

RESULTS

Forty-nine potential outcome parameters for Dutch P-HEMS care were surveyed. Of 71 invited participants, 53 (75%), 40 (56%), and 20 (28%) participated in the first, second, and third round of the Delphi study, respectively. Consensus was reached on 25 (51%) of 49 outcome parameters as being important. These consisted of seven long term patient related outcome parameters, four short term patient related outcome parameters, five process outcome parameters and nine performance outcome parameters.

CONCLUSIONS

In conclusion, this study identified 25 outcome parameters relevant for Dutch physician staffed HEMS care. These parameters should be considered when designing future studies and should be routinely collected for each dispatch if possible.

Survival Benefit of Helicopter Scene Response for Patients with an Injury Severity Score of at Least Nine: A Systematic Review and Meta-Analysis

BACKGROUND AND AIM

Helicopter EMS (HEMS) is a well-established mode of rapid transportation for patients with need for time-sensitive interventions, especially in patients with significant traumatic injuries. Traditionally in the setting of trauma, HEMS is often considered appropriate when used for patients with "severe" injury as defined by Injury Severity Score (ISS) >15. This may be overly conservative, and patients with a lower ISS may benefit from HEMS-associated speed or care quality. Our objective was to perform a meta-analysis of trauma HEMS transports to evaluate for possible mortality benefit in injured cases defined by an ISS score >8, lower than the customary ISS cutoff of >15.

METHODS

A broad search of the literature was performed including PubMed, EMBASE, SCOPUS, Cochrane Central Register of Controlled Trials, and Google Scholar from the years 1970 to 2022. The gray literature and reference lists of included publications were also examined. We included studies with the outcome of mortality in HEMS vs control in trauma transports from scene of injury for patients (adult or pediatric) with ISS > 8.

RESULTS

Nine eligible studies were used in the final analysis: six in the primary analysis and three in sensitivity analysis due to patient overlap. All studies reported statistically significant survival benefit in HEMS compared to control group. The minimum survival odds ratio (OR) benefit observed was OR 1.15 (95% CI 1.06-1.25) and maximum was OR 2.04 (95% CI 1.18-3.57). Risk of bias tool (ROBINS-I) application yielded moderate to low risk of bias, mainly due to the observational nature of the studies included.

CONCLUSIONS

There was a statistically significant survival benefit in patients with ISS > 8 when HEMS was used over traditional ground ambulance transportation, although novel and more inclusive trauma triage criteria may be more appropriate in the future to guide HEMS utilization decision-making. Restricting HEMS to trauma patients with ISS >15 likely misses survival benefit that could be afforded to the subset of trauma patients with serious injury.

Helicopter Emergency Medical Services Literature 1972-2017: Characteristics and Trends

Since its inception in the latter part of the 20th century, the rapid expansion of helicopter emergency medical services (HEMS) has been accompanied by remarkable growth in the relevant evidence base. There are many review articles describing lessons contained within the various arenas of HEMS literature, but there is little or no characterization of the numbers and types of publications comprising the HEMS-related evidence base. This study analyzed all indexed publications mentioning HEMS (with abstract included) in the United States National Library of Medicine's PubMed collection. The aims of the analysis were to provide quantitative, qualitative, and longitudinal trend information regarding the 1972 to 2017 evidence base relevant to HEMS.