Developing a South African Helicopter Emergency Medical Service Activation Screen (SAHAS): A Delphi study

A Retrospective Geospatial Simulation Study of Helicopter Emergency Medical Services' Potential Time Benefit Over Ground Ambulance Transport in Northern South Africa

OBJECTIVE

One of the most important benefits of helicopter emergency medical services (HEMS) is a time benefit, either through expedited access to the casualty or a reduction in the transport time to definitive care. However, HEMS utilization does not come without risk to the public and crew or at an insignificant cost. Cost is an essential consideration for health policy decisions, especially in low- to middle-income countries, such as South Africa. The aim of this study was to determine whether there is a time benefit of HEMS dispatch in South Africa compared with simulated driving time. A secondary aim was to determine the distance from the incident site to the hospital at which a time benefit can be guaranteed.

METHODS

A retrospective study was undertaken by comparing the prehospital times of patients who underwent HEMS transportation with simulated ground emergency medical services (GEMS) transportation times. Handwritten patient records of actual flights were reviewed and analyzed. The actual flight times recorded were used to calculate the helicopter transport time, activation to scene time, scene time, and scene to hospital time. Times were assigned based on a nonsimultaneous dispatch model, as is used in South Africa. For each helicopter mission, Google Maps (Google Inc, Mountain View, CA) was used to simulate the fastest ground route from the same location of the incident to the same receiving hospital corrected for typical traffic trends. The actual HEMS and simulated GEMS times were compared using the paired t-test. Linear regression analysis was performed to determine a minimum driving distance at which HEMS provides a time benefit.

RESULTS

A total of 118 HEMS transports were analyzed, the majority of which were trauma related (n = 115, 97%). HEMS transport resulted in a mean time deficit of -15 minutes (95% confidence interval, -18 to -11; P < .05) compared with simulated GEMS drive times. After regression, HEMS transport provides a time benefit at a driving distance greater than 119 km.

CONCLUSION

The current study demonstrated that there was rarely a time benefit for actual primary emergency responses when HEMS was used compared with simulated driving time of GEMS transport. Using a nonsimultaneous dispatch model, a time benefit only occurs when the driving distance from the incident site to the hospital is greater than 119 km. There is an urgent need to critically evaluate HEMS utilization in the South African context.

A 12-month retrospective descriptive analysis of a single helicopter emergency medical service operator in four South African provinces

Introduction

Helicopter Emergency Medical Services (HEMS) is integrated into modern emergency medical services because of its suggested mortality benefit in certain patient populations, it is an expensive resource and appropriate use/feasibility in low- to middle income countries (LMIC) is highly debated. To maximise benefit, correct patient selection in HEMS is paramount. To achieve this, current practices first need to be described. The study aims to describe a population of patients utilising HEMS in South Africa, in terms of flight data, patient demographics, provisional diagnosis, as well as clinical characteristics and interventions.

Methods

A retrospective flight- and patient-chart review were conducted, extracting clinical and mission data of a single aeromedical operator in South Africa, over a 12-month period (July 2017 - June 2018) in Gauteng, Free State, Mpumalanga and North-West provinces.

Results

A total of 916 cases were included (203 primary cases, 713 interfacility transport (IFT) cases). Most patients transported were male (n=548, 59.8%) and suffered blunt trauma (n=379, 41.4%). Medical pathology (n=247, 27%) and neonatal transfers (n=184, 20.1%) follows. Flights occurred mainly in daylight hours (n=729, 79.6%) with median mission times of 1-hour 53 minutes (primary missions), and 3 hours 10 minutes (IFT missions). Median on-scene times were 26 minutes (primary missions) and 55 minutes (IFT missions). Almost half were transported with an endotracheal tube (n=428, 46.7%), with a large number receiving no respiratory support (n=414, 45.2%). No patients received fibrinolysis, defibrillation, cardioversion or cardiac pacing. Intravenous fluid therapy (n=867, 94.7%) was almost universal, with common administration of sedation (n=430, 46.9%) and analgesia (n=329, 35.9%).

Conclusion

Apart from the lack of universal call-out criteria and response to the high burden of trauma, HEMS seem to fulfil an important critical care transport role. It seems that cardiac pathologies are under-represented in this study and might have an important implication for crew training requirements.

Rescue Activity of a Civilian Helicopter Emergency Medical Service in the Western Cape, South Africa: A 5-Year Retrospective Review

INTRODUCTION

Helicopter search and rescue (SAR) in Africa is conducted primarily by military organizations. Since 2002, the Western Cape of South Africa has had a dedicated contracted civilian helicopter emergency medical service (HEMS) conducting air ambulance, terrestrial, and aquatic rescue. To our knowledge, this is the first description of the operations of an African helicopter rescue service.

METHODS

A 5-y retrospective review of the terrestrial and aquatic helicopter rescue activity of a civilian-operated HEMS in the Western Cape, South Africa, from January 1, 2012 through December 31, 2016, was conducted. Data were extracted from the organization's operational database, aviation documents, rescue reports, and patient care records. Patient demographics and activity at the time of rescue, temporal and geographical distribution, crewing compositions, patient injury, triage, clinical interventions, and rescue techniques were analyzed.

RESULTS

A total of 581 SAR missions were conducted, of which 451 were terrestrial and 130 were aquatic rescues. The highest volume of rescues was conducted within the urban Cape Peninsula. Hoisting using a rescue harness was the most common rescue technique used. A total of 644 patients were rescued, with no or minor injuries representing 79% of the sample. Trauma (33%, 196/644) was the most common medical reason for rescue, with lower limb trauma predominant (15%, 90/644). The most common clinical interventions performed were intravenous access (n=108, 24%), spinal immobilization (n=92, 21%), splinting (n=76, 17%), and analgesia administration (n=58, 13%).

CONCLUSIONS

The rescue techniques utilized are similar to those described in high-income settings. Uninjured patients comprised the majority of the patients rescued.

A descriptive study of trauma patients transported by helicopter emergency medical services to a level one trauma centre

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Helicopter Emergency Medical Service (HEMS) remains an important option in Africa to address long distance transfers.

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There is insufficient evidence to assess the impact of HEMS on outcomes in the setting of Trauma in a LMIC

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Further evidence-based research is needed to evaluate Helicopter Emergency Medical Service in a LMIC as far as its impact on significantly shortening the time of transfer to definitive care for patients with time-sensitive medical or surgical conditions.

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Evidence-based research should evaluate the impact of HEMS in a LMIC regarding its role in providing specialized medical expertise or equipment to patients before and/or during transport, especially patients who are in inaccessible or obscure environments.

Background

KwaZulu-Natal, the largest land mass province that is densely populated in SA has vast distances to referral centres and time to definitive treatment is key in trauma care. Helicopter Emergency Medical Service (HEMS) is still an invaluable prehospital asset for the transport of time sensitive trauma. This study reviews the impact of HEMS in the management of trauma at Inkosi Albert Luthuli hospital (IALCH) which is the only public accredited level one trauma centre in the province.

Methods

A retrospective descriptive study of polytrauma patients transported by HEMS in KZN to IALCH over a three-year period from 01 January 2014 to 31 December 2016. Data was collected around patient demographics, transfer details and patient outcomes.

Results

Over the three-year period, 117 HEMS transfers were reviewed, with the majority being male (90.6%). Just 26% of HEMS transfers were direct from the scene, with the balance being interhospital transfers largely from distant regional hospitals around the province. Some 60% of injuries were caused by vehicle crashes, and 31% by intentional injury. Mortality was 30% which is reflective of the high severity of injury of the cohort. The injury severity scores (ISS) (median 26 overall) of those who died was higher (median 38) (P-= .0002), and there were more interventions before and during transfer such as thoracostomy, ventilation and immobilization. Overall, 88% required admission to ICU at IACLH.

Conclusions

HEMS in the KwaZulu Natal province was mainly used for long-distance transfer of major trauma patients which is an appropriate use of this essential service, given the single major trauma centre in the province. The majority of patients that were transported by HEMS had severe injury, which was also associated with increased mortality outcomes. Rational use of this essential but expensive resource will require clear policy around the role of HEMS and call out criteria in each setting.

Improving ambulance dispatch triage to trauma: A scoping review using the framework of development and evaluation of clinical prediction rules

OBJECTIVE

Ambulance dispatch algorithms should function as clinical prediction rules, identifying high acuity patients for advanced life support, and low acuity patients for non-urgent transport. Systematic reviews of dispatch algorithms are rare and focus on study types specific to the final phases of rule development, such as impact studies, and may miss the complete value-added evidence chain. We sought to summarise the literature for studies seeking to improve dispatch in trauma by performing a scoping review according to standard frameworks for developing and evaluating clinical prediction rules.

METHODS

We performed a scoping review searching MEDLINE, EMBASE, CINAHL, the CENTRAL trials registry, and grey literature from January 2005 to October 2021. We included all study types investigating dispatch triage to injured patients in the English language. We reported the clinical prediction rule phase (derivation, validation, impact analysis, or user acceptance) and the performance and outcomes measured for high and low acuity trauma patients.

RESULTS

Of 2067 papers screened, we identified 12 low and 30 high acuity studies. Derivation studies were most common (52%) and rule-based computer-aided dispatch was the most frequently investigated (23 studies). Impact studies rarely reported a prior validation phase, and few validation studies had their impact investigated. Common outcome measures in each phase were infrequent (0 to 27%), making a comparison between protocols difficult. A series of papers for low acuity patients and another for pediatric trauma followed clinical prediction rule development. Some low acuity Medical Priority Dispatch System codes are associated with the infrequent requirement for advanced life support and clinician review of computer-aided dispatch may enhance dispatch triage accuracy in studies of helicopter emergency medical services.

CONCLUSIONS

Few derivation and validation studies were followed by an impact study, indicating important gaps in the value-added evidence chain. While impact studies suggest clinician oversight may enhance dispatch, the opportunity exists to standardize outcomes, identify trauma-specific low acuity codes, and develop intelligent dispatch systems.

Helicopter Emergency Medical Services in Trauma Does Not Influence Mortality in South Africa

OBJECTIVE

Sub-Saharan Africa carries a large trauma burden. Helicopter emergency medical services (HEMS) have been suggested to reduce prehospital time and mortality. It is not clear whether HEMS infers a mortality benefit over ground transport in South Africa. This study aimed to determine whether HEMS improved 30-day mortality over ground emergency medical services (GEMS).

METHODS

A retrospective, case-control study was undertaken for major trauma patients transported to a private trauma center in Johannesburg. A 1-year cohort of HEMS patients was extracted and matched to GEMS patients based on mechanism, injury severity or percentage of the total body surface area burned, age, sex, and comorbidities. The odds ratio (OR) for 30-day mortality was calculated to determine the risk of death.

RESULTS

A total of 822 cases (HEMS: 272 [33%], GEMS: 550 [67%]) were reviewed. We included 410 patients in the matched cohort with equal distribution between transportation modes. The OR for mortality in the total cohort was 2.69 (95% confidence interval, 1.6-4.6; P = .003) for HEMS patients, whereas in the matched cohort the OR was 1.35 (95% confidence interval, 0.5-3.4; P = .503) for patients transported by HEMS.

CONCLUSION

In a matched cohort of major trauma patients, HEMS does not seem to improve mortality over GEMS. These results might reflect the South African HEMS dispatch model.