What clinical crew competencies and qualifications are required for helicopter emergency medical services? A review of the literature

A search strategy was devised with the assistance of a research librarian and a search of the literature was conducted from 1 January 2009 to 30 August 2019. The search included all peer-reviewed articles in MEDLINE, including quantitative and qualitative studies, and literature reviews. Conference abstracts/proceedings, grey literature, and articles that were written in a language other than English were excluded. A similar search was performed in both Web of Science and EMBASE. The review question was constructed according to the patients, interventions, comparator and outcome (PICO) strategy recommended by the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols (PRISMA-P) 2015 Checklist [1]:

“In the population of patients who are acutely injured or unwell and attended by a Helicopter Emergency Medical Service, what combination of competencies and qualifications of the clinical crew are required to provide the appropriate level of care?”

Three search terms were built using the ‘Title/Abstract’ and ‘MeSH’ descriptors in MEDLINE; ‘qualifications’; ‘competencies’; and ‘helicopter emergency service’ (see Supplementary file A). A separate search was performed in the Cochrane Database of Systematic Reviews, using only the MeSH descriptor of ‘air ambulances’. All article citations were imported into Endnote Desktop Version X9.2 (Bld 13,018) and duplicate articles were identified and removed using the ‘find duplicates’ function in Endnote. A description of the search strategy is provided in the Supplementary Files.

The review protocol was registered with the international prospective register of systematic reviews PROSPERO (Registration number: CRD42020151104).

Broad search terms were used in order to ensure comprehensive capture of relevant articles. Two reviewers performed the selection of articles based on the review question, initially identifying all articles where the title and/or abstract made specific mention of ‘staffing’, ‘configuration’, ‘competencies’ and/or ‘qualifications’. Case reviews were excluded due to the limited ability to generalise the data from such studies. For studies published using data from the same cohort of patients over the same timeframe and using similar outcome measures, the most recent publication only was included. Instances of disagreement were discussed to meet consensus. Articles that described inter-facility care only were also excluded in order to ensure the primary focus of the review was on emergency care provision. Full-text articles were then downloaded and comprehensively assessed for eligibility (see Fig. 1).

Full-text articles were reviewed and data was extracted under the following headings:

The quality of the randomised controlled trial (RCT), the systematic review and cohort studies, were assessed using critical appraisals checklists as guides (https://​casp-uk.​net/​casp-tools-checklists/​). Questionnaire/survey type studies were assessed using the Critical Appraisal of a Cross-Sectional Study (Survey) from the Centre for Evidence-based Management (https://​www.​cebma.​org/​wp-content/​uploads/​Critical-Appraisal-Questions-for-a-Survey.​pdf) (see Supplementary Tables 1, 2, 3 and 4).

Following a quality review of each full-text article for which data was extracted, data from the remaining articles was tabulated and a narrative synthesis describing commonly identified competencies was produced. This analysis was used to develop conclusions and recommendations about the type of clinical crew needed for HEMS and to identify requirements for further research and analysis. As described in the introduction, because of the degree of heterogeneity in HEMS models internationally, there was also heterogeneity in patient outcomes published. This meant that meta-analysis based on patient outcomes was not performed.

In jurisdictions where HEMS were either solely or primarily doctor-staffed, there was a difference in medical specialties needed to operate as a HEMS doctor. It should be noted that the specialties of emergency medicine and prehospital emergency medicine are not established in all countries where HEMS models were operational, which may in part explain the emphasis on in-hospital acute care specialties. There was also a vast difference in the competencies of nurses and paramedics employed on HEMS. The range of clinical crew models described in the literature is summarised in Table 1.

Andrew and colleagues described advanced procedures carried out by Intensive Care Flight Paramedics (ICFPs) in Victoria and highlighted the successful application of pain reduction, rapid sequence induction (RSI) and administration of red blood cell products [3]. Von Volpelius-Feldt et al. identified a range of additional competencies brought by critical care paramedics and HEMS doctors, but highlighted the value of doctor-CCP team working in facilitating critical care paramedic practice [12]. This theme of combined competencies was continued by Van der Eng and colleagues, who used a Delphi process to devise three indicators of quality in the management of patients with poly-trauma, i.e. education, exposure and experience [15]. In a sample of 442 patients, they estimated that 220 patients were treated by a fully competent team i.e. fulfilled the three indicators of competency. Van Schuppen and Bierens initially identified the additional skills that a doctor added to HEMS, [29] and in a later study identified that doctors added qualitative skills that were less tangible such as clinical judgement and impact on decision-making [11]. However, while the studies described enhanced competencies provided by different types of HEMS clinical crews, they did not estimate the impact of these additional competencies on patient outcomes. Competencies identified in the literature are presented in Table 2.

As stated above, studies comparing HEMS to ground-based EMS suggested better patient outcomes, although it should be remembered that the studies reviewed had an observational design. In studies where the HEMS and ground-based EMS had similar qualifications, for patients suffering severe trauma, HEMS intervention was almost invariably associated with better patient outcomes. For example, in Germany, where both HEMS and ground-based EMS are doctor-staffed and have similar clinical competencies, two studies showed that HEMS was associated with an adjusted decrease in in-hospital mortality [18, 20]. In a French study, where doctor-staffed mobile intensive care units (MICUs) were deployed to patients with severe blunt trauma either by road or helicopter, adjusted mortality was lower for patients attended by helicopter-based MICU compared with those attended by a road-based unit [19]. In two US studies using data from the National Trauma bank, paramedic/nurse-staffed HEMS was associated with improved patient outcomes when compared to paramedic-staffed ground-based EMS [17, 31]. Similarly, a further US study suggested that while HEMS patients tended to be sicker, HEMS provision enabled better adherence to sepsis guidelines due to shorter transport times [30].

In HEMS models where the qualifications of the HEMS crew were more advanced than those of the ground-based EMS crew, studies also suggested that HEMS improved patient outcomes. In New South Wales where HEMS was doctor-staffed, it was estimated that the adjusted odds of dying in hospital was three to four times higher for ground-transported adult patients who suffered major trauma when compared to HEMS-treated patients [23]. Also in New South Wales, when the identification and triaging of paediatric drowning patients by HEMS doctors was discontinued, this resulted in incorrect transport of paediatric patients to adult facilities [33]. While statistical significance was not reached due to small numbers, prehospital rapid sequence induction (RSI) intubation by ICFPs in Victoria was associated with a shorter hospital stay and more favourable six-month functional outcome, when compared with usual care by ground crews who did not perform intubation [14]. In a propensity-matched analysis of data from the Japan Trauma Bank, doctor-staffed HEMS were associated with improved odds of survival, [16] as was also the case in South Korea [32]. In the Netherlands, where advanced medical procedures are restricted to doctor-staffed HEMS, Ringburg and colleagues estimated that HEMS was both cost-effective and responsible for saving an additional 29 lives following severe trauma over a four-year period (2003–2006) [22]. A later Dutch study in a single centre confirmed these findings [21]. Finally, the PHANTOM study in the UK concluded that HEMS that were staffed by an enhanced care team (ECT) of doctors and critical care paramedics (CCPs) had a statistically significant benefit in adjusted survival rates for severe trauma patients when compared to patients solely treated by a ground-based paramedic [28].

The literature identified in this review contained very limited data comparing different crew qualifications and competencies. This means that while descriptions of the clinical crew composition and competencies were provided, the association between the clinical crew type and patient outcome is unclear. Additionally, there was probable publication bias towards doctor-staffed HEMS models as evidenced by the low number of US and Canadian models represented in the search results. Studies included were primarily of low grade, with only two studies describing trial results. Additionally, while the review provides descriptions of practice in Australia and Europe, there appears to be limited availability of published academic literature from the United States, Canada, and other international jurisdictions. In summary, due to the fact that literature on this subject is limited in availability and poorly indexed, it is exceedingly difficult to come to definitive conclusions about the type of clinical crew qualifications and competencies will best serve HEMS patients.