Helicopter EMS: Research Endpoints and Potential Benefits

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.

Use of Helicopter Emergency Medical Services in the Transport of Patients With Known or Suspected Coronavirus Disease 2019

OBJECTIVE

Limited information exists regarding the response of helicopter emergency medical services (HEMS) programs to patients with known or suspected coronavirus disease 2019 (COVID-19). The purpose of this study was to determine changes in flight operations during the early stages of the pandemic.

METHODS

A survey of the American College of Emergency Physicians Air Medical Section was conducted between May 13, 2020, and August 1, 2020. COVID-19 prevalence was defined as high versus low based on cases > 2,500 or ≤ 2,500.

RESULTS

Of the 48 respondents, the majority (89.6%) reported that their patient guidelines had changed because of COVID-19; 89.6% of programs reported transporting COVID-19-positive patients, whereas 91.5% reported transporting persons under investigation. The majority of respondents reported additional training in COVID-19 airway management (79.2%) and personal protective equipment use (93.6%). Permitted aerosol-generating procedures included bilevel positive airway pressure (40.4%) and high-flow nasal oxygen (66.0%). No difference in guideline changes, positive COVID-19/persons under investigation transport restrictions, or permitted aerosol-generating procedures were noted between high- and low-prevalence settings.

CONCLUSION

COVID-19 has resulted in changes to HEMS guidelines regardless of local disease prevalence. The pandemic has persisted sufficiently long that data regarding the effectiveness of guideline changes should be analyzed. In the absence of definitive data, national best practices should be developed to guide COVID-19 HEMS transport.

Rescue Operations Lead to Increased Cardiovascular Stress in HEMS Crew Members: A Prospective Pilot Study of a German HEMS Cohort

Helicopter emergency medical service (HEMS) is an essential part of prehospital emergency medicine. The working conditions lead to high physical stress, especially in rescue operations. The study aimed to determine the cardiovascular stress profile during rescue situations in HEMS crew members. Twenty-one HEMS crew members (male n = 20) participated in the prospective study. Heart rate, blood pressure and long-term ECG measurements were recorded during the whole operation day. The changes of measurements during rescue operation (52 operations in total) were compared to these of standby time. Rescue operations lead to increased load on the cardiovascular system, as expressed by significantly higher blood pressure, heart rate values and rate of cardiac events compared to standby time. Of special note, the difference in systolic blood pressure mean was 7.4 ± 9.0 mmHg (CI [5.1; 9.7], p < 0.001). Maximal heart rate was on average 33.7 bpm higher during rescue operation than in the standby time (CI [26.2; 40.8], p < 0.001). Cardiac events occurred significantly more frequently during the period of rescue operation than in standby time hours (p = 0.02). The results reported a significant load on the cardiovascular system during rescue operations in HEMS crew members. Therefore, it is necessary to carry out a risk stratification of the HEMS crew members to prevent cardiovascular risk and events.

Helicopter Neonatal Transport: First Golden Hour at Birth Is Useful Tool Guiding Activation of Appropriate Resources

OBJECTIVE

A lack of consensus exists about the appropriate criteria to activate a helicopter during neonatal transport. The aim of the present study was to explore the possible guiding criteria to justify helicopter activation for neonatal transport (NETS).

METHODS

This was a retrospective study of the Gaslini Genoa NETSs from February 1995 to December 2019. The flight and driving times and the reason for helicopter neonatal transport activation were obtained for every subject from the online NETS clinical database. Driving and flight data (mean and standard deviation [SD]) were compared using the Student t-test (P < .05).

RESULTS

Five thousand eight hundred sixty-six transported newborn infants were identified. A significant difference emerged between the overall ground (mean = 99.2 minutes [SD = 15.7 minutes]) and overall helicopter transport times (mean = 27.8 minutes [SD = 11.9 minutes], P < .0001). Considering the "golden hour," the chance to stabilize the patient within this time frame could have been possible for 4 of 5 neonatal care centers when using a helicopter.

CONCLUSION

On the basis of our observations, we suggest including the golden hour as 1 of the guiding criteria justifying helicopter activation, especially if applied to the reason of transport and the quality of assistance the newborn will receive while waiting for the NETS team.

The Impact of Air Transport for Acute Coronary Syndrome Patients

OBJECTIVE

For patients with acute coronary syndrome (ACS), percutaneous coronary intervention (PCI) within 120 minutes from onset is recommended. A helicopter emergency medical service (HEMS) is useful for transporting ACS patients. The purposes of this study were to investigate whether patients with ACS in the eastern part of Hokkaido could be transported to a PCI hospital by HEMS and undergo PCI within 120 minutes and to clarify the factors most related to delayed access to PCI.

METHODS

This was a retrospective cohort study that analyzed 513 patients diagnosed with ACS at our institution, an HEMS base/PCI hospital. We investigated transport modes for each patient and identified the processes by which access to PCI was delayed.

RESULTS

HEMS reduced transport time compared with ground emergency medical services but did not contribute to access to PCI within 120 minutes. The most important factor was transport directly to a PCI hospital (P < .01).

CONCLUSION

HEMS did not achieve a total transport time of patients to a PCI hospital within 120 minutes from onset. Transport using HEMS is insufficient to access early PCI; patient condition must also be considered to determine whether to go through a non-PCI hospital.

Clinical Interventions Account for Scene Time in a Helicopter Emergency Medical Service in South Africa

INTRODUCTION

Helicopter emergency medical services (HEMS) have been associated with a prolonged scene time, compromising the time benefit in an urban setting. Therefore, the clinical benefit offered through additional equipment, skills, and experience of HEMS crews must be investigated to propose the value of HEMS. This study aimed at establishing whether HEMS scene time was associated with the number of clinical interventions performed and improved patient stability.

METHOD

This retrospective, cross-sectional chart review included all primary HEMS cases from June 1, 2013, to May 31, 2015, from a South African helicopter service and extracted the number of clinical interventions and patient stability using the Mainz Emergency Evaluation Score (MEES). We correlated this with scene time using analysis of variance.

RESULTS

Five hundred fourteen clinical interventions were performed on 204 patients. A median of 2 clinical interventions per patient was performed on scene. Performing 1 additional clinical intervention was associated with an approximate 4-minute increase in on-scene time. Some improvement in patient stability was shown by a mean change in the MEES of 0.65 after on-scene intervention, but this did not reach MEES clinical cutoff measures.

CONCLUSION

The number of clinical interventions performed by helicopter crews can account for scene time in a South African HEMS. The clinical interventions performed by helicopter crews tend to have a positive effect on patient stability.

Helicopter EMS and rapid transport for ST-elevation myocardial infarction: The HEARTS study

Background: Helicopter emergency medical services (HEMS) and ground EMS (GEMS) are both integral parts of out-of-hospital transport systems for patients with ST-elevation myocardial infarction (STEMI) undergoing emergency transport for primary percutaneous coronary intervention (PPCI). There are firm data linking time savings for PPCI transports with improved outcome. A previous pilot analysis generated preliminary estimates for potential HEMS-associated time savings for PPCI transports. Methods: This non-interventional multicenter study conducted over the period 2012–2014 at six centers in the USA and in the State of Qatar assessed a consecutive series of HEMS transports for PPCI; at one center consecutive GEMS transports of at least 15 miles were also assessed if they came from sites that also used HEMS (dual-mode referring hospitals). The study assessed time from ground or air EMS dispatch to transport a patient to a cardiac center, through to the time of patient arrival at the receiving cardiac unit, to determine proportions of patients arriving within accepted 90- and 120-minute time windows for PPCI. Actual times were compared to “route-mapping” GEMS times generated using geographical information software. HEMS' potential time savings were calculated using program-specific aircraft characteristics, and the potential time savings for HEMS was translated into estimated mortality benefit. Results: The study included 257 HEMS and 27 GEMS cases. HEMS cases had a high rate of overall transport time (from dispatch to receiving cardiac unit arrival) that fell within the predefined windows of 90 minutes (67.7% of HEMS cases) and 120 minutes (91.1% of HEMS cases). As compared to the calculated GEMS times, HEMS was estimated to accrue a median time saving of 32 minutes (interquartile range, 17–46). The number needed to transport for HEMS to get one additional case to PPCI within 90 minutes was 3. In the varied contexts of this multicenter study, the number of lives saved by HEMS, solely through time savings, was calculated as 1.34 per 100 HEMS PPCI transports. Conclusions: In this multicenter study, HEMS PPCI transport was found to be appropriate as defined by meeting predefined time windows. The overall estimate for lives saved through time savings alone was consistent with previous pilot data and was also generally consistent with favorable cost-effectiveness. Further research is necessary to confirm these findings, but judicious HEMS deployment for PPCI transports is justified by these data.

A retrospective comparison of helicopter transport versus ground transport in patients with severe sepsis and septic shock

Background

Helicopter emergency medical services (HEMS) extend the reach of a tertiary care center significantly. However, its role in septic patients is unclear. Our study was performed to clarify the role of HEMS in severe sepsis and septic shock.

Methods

This is a single-center retrospective cohort study. This study was performed at Mayo Clinic, Rochester, MN, in years 2007–2009. This study included a total of 181 consecutive adult patients admitted to the medical intensive care unit meeting criteria for severe sepsis or septic shock within 24 h of admission and transported from an acute care facility by a helicopter or ground ambulance. The primary predictive variable was the mode of transport. Multiple demographic, clinical, and treatment variables were collected and analyzed with univariate analysis followed by multivariate analysis.

Results

The patients transported by HEMS had a significantly faster median transport time (1.3 versus 1.7 h, p < 0.01), faster time to meeting criteria for severe sepsis or septic shock (1.2 versus 2.9 h, p < 0.01), a higher SOFA score (9 versus 7, p < 0.01), higher incidence of acute respiratory distress syndrome (38 versus 18 %, p = 0.013), higher need for invasive mechanical ventilation (60 versus 41 % p = 0.014), higher ICU mortality (13.3 versus 4.1 %, p = 0.024), and an increased hospital mortality (17 versus 30 %, p = 0.04) when compared to those transported by ground. Distance traveled was not an independent predictor of hospital mortality on multivariate analysis.

Conclusions

HEMS transport is associated with faster transport time, carries sicker patients, and is associated with higher hospital mortality compared with ground ambulance services for patients with severe sepsis or septic shock.

Spinal Cord Injuries and Helicopter Emergency Medical Services, 6,929 Patients: A Multicenter Analysis

OBJECTIVE

Traumatic spinal cord injury (SCI) impacts quality of life for patients and caregivers, generating lifetime costs in the millions. Previous studies show delayed treatment of SCI patients at specialized centers is linked to complicated outcomes and extended hospitalizations. This study characterizes helicopter emergency medical service (HEMS) use in SCI and develops a methodology to study large volumes of HEMS electronic medical record data from multiple providers.

METHODS

This descriptive study used deidentified data of HEMS providers that use Golden Hour Data Systems, Inc (San Diego, CA) software service from 34 states in the United States from 2004 to 2011. Demographic and logistical data underwent a deidentification protocol developed specifically for this study before analysis.

RESULTS

Six thousand nine hundred twenty-nine SCI patients were transported. HEMS use increased but decreased relative to total transports from 2004 to 2011. The average patient was 39 ± 21 years old, male, and had a 63-minute total transport time. The largest age bracket was 15 to 25 years.

CONCLUSION

HEMS improved access for SCI patients to all localities and generally took under 2 hours. SCI patients are mostly young adult males, thus supporting the loss of years of productivity and also supporting the high lifetime cost for care for SCI. This study created a methodology for future multicenter aggregate data studies.

Long-term follow-up of trauma patients before and after implementation of a physician-staffed helicopter: A prospective observational study

INTRODUCTION

The first Danish Helicopter Emergency Medical Service (HEMS) was introduced May 1st 2010. The implementation was associated with lower 30-day mortality in severely injured patients. The aim of this study was to assess the long-term effects of HEMS on labour market affiliation and mortality of trauma patients.

METHODS

Prospective, observational study with a maximum follow-up time of 4.5 years. Trauma patients from a 5-month period prior to the implementation of HEMS (pre-HEMS) were compared with patients from the first 12 months after implementation (post-HEMS). All analyses were adjusted for sex, age and Injury Severity Score.

RESULTS

Of the total 1994 patients, 1790 were eligible for mortality analyses and 1172 (n=297 pre-HEMS and n=875 post-HEMS) for labour market analyses. Incidence rates of involuntary early retirement or death were 2.40 per 100 person-years pre-HEMS and 2.00 post-HEMS; corresponding to a hazard ratio (HR) of 0.72 (95% confidence interval (CI) 0.44-1.17; p=0.18). The HR of involuntary early retirement was 0.79 (95% CI 0.44-1.43; p=0.43). The prevalence of reduced work ability after three years were 21.4% vs. 17.7%, odds ratio (OR)=0.78 (CI 0.53-1.14; p=0.20). The proportions of patients on social transfer payments at least half the time during the three-year period were 30.5% vs. 23.4%, OR=0.68 (CI 0.49-0.96; p=0.03). HR for mortality was 0.92 (CI 0.62-1.35; p=0.66).

CONCLUSIONS

The implementation of HEMS was associated with a significant reduction in time on social transfer payments. No significant differences were found in involuntary early retirement rate, long-term mortality, or work ability.

Prehospital Helicopter Air Ambulances Part 1: Access, Protocols, and Utilization

OBJECTIVE

In the prehospital setting, helicopter air ambulances (HAAs) are used to bring advanced care to patients and reduce time to definitive care. Research related to emergency medical service (EMS) professionals' access to medical helicopters, protocols for HAA use, and prevalence of HAA transport for different patient types is sparse. Our first objective was to describe EMS professionals' access to HAA and the prevalence of written protocols regarding their use. Next, we looked at HAA use for specific patient types (trauma, nontraumatic chest pain, stroke, and pediatric).

METHODS

We conducted a census survey of nationally certified EMS professionals. Descriptive analyses were performed.

RESULTS

There were 15,366 responses. Over 90% of nationally certified EMS professionals had access to at least 1 HAA service. Of these, 86% had the authority to request a medical helicopter, and two thirds reported having written HAA protocols. Although HAAs were used mostly for trauma patients, EMS professionals also used these resources for nontrauma transports of patients with time-sensitive conditions.

CONCLUSION

Most nationally certified EMS professionals had access to a medical helicopter service and used these resources mainly for trauma patients. About one third reported they did not have or were unsure if their agency had written protocols for HAA use.

Prehospital Helicopter Air Ambulances Part 2: Utilization Criteria and Training

OBJECTIVES

The decision to request a helicopter air ambulance (HAA) is critical and complex. Emergency medical service (EMS) professionals must know how to appropriately and safely use HAA resources. We sought to describe important criteria for using HAA and the prevalence of HAA-related training among EMS professionals. Then, we identified characteristics associated with receiving training.

METHODS

We sent an electronic questionnaire to all nationally certified EMS professionals. We performed descriptive analyses and multivariable logistic regression modeling.

RESULTS

We received 15,366 responses. Nearly all respondents reported that time to nearest trauma center and mechanism of injury were important in their last decision to use a HAA. About two thirds received HAA safety training (66.7%), whereas 69.0% received HAA utilization training within the past 24 months. Nearly three fourths (74.2%) received training in at least 1 HAA-related topic. Providers working at advanced life support levels, fire-based services, agencies providing 911 response, or in rural communities had greater odds of having received HAA training, whereas women, members of minority ethic/racial groups, and those with higher weekly call volumes had decreased odds.

CONCLUSION

Although their decision-making criteria appear to include the major factors recommended within current evidence-based guidelines, many nationally certified EMS professionals had not received recent HAA training.

Helicopter patient transportation service on the Ulleung Island, South Korea

INTRODUCTION

Despite numerous studies of helicopter emergency medical services, few reports have examined the outcomes of patients transported by helicopter across the sea from isolated islands. We analyzed helicopter transportation from the isolated Ulleung Island, which lies to the east of the South Korean mainland.

METHODS

This study included 284 patients transported from the Ulleung Island to mainland hospitals between January 2007 and March 2013. Emergency Severity Index and Injury Severity Score were calculated. Hospital stay time and flight duration was measured. Data were analyzed using Student's t-test.

RESULTS

The mean age of the patients was 53.5 years. Of the transported patients, 19.0% were visitors to the island and 29.6% were traumatically injured. The mortality rate after transportation was 11.6% (33 patients).

CONCLUSION

Helicopter transportation has been very beneficial for the treatment of emergency patients on Ulleung Island. A national level of interest and investment is required to improve this service.

Cross-sectional investigation of HEMS activities in Europe: a feasibility study

Objectives. To gather information on helicopter emergency medical services (HEMSs) activities across Europe. Methods. Cross-sectional data-collection on daily (15 November 2013) activities of a sample of European HEMSs. A web-based questionnaire with both open and closed questions was used, developed by experts of the European Prehospital Research Alliance (EUPHOREA). Results. We invited 143 bases from 11 countries; 85 (60%) reported base characteristics only and 73 (51%) sample-day data too. The variety of base characteristics was enormous; that is, the target population ranged from 94.000 to 4.500.000. Of 158 requested primary missions, 62 (0.82 per base) resulted in landing. Cardiac aetiology (36%) and trauma (36%) prevailed, mostly of life-threatening severity (43%, 0.64 per mission). Had HEMS been not dispatched, patients would have been attended by another physician in 67% of cases, by paramedics in 24%, and by nurses in 9%. On-board physicians estimated to have caused a major decrease of death risk in 47% of missions, possible decrease in 22%, minor benefit in 17%, no benefit in 11%, and damage in 3%. Earlier treatment and faster transport to hospital were the main reasons for benefit. The most frequent therapeutic procedure was drug administration (78% of missions); endotracheal intubation occurred in 25% of missions and was an option hardly offered by ground crews. Conclusions. The study proved feasible, establishing an embryonic network of European HEMS. The participation rate was low and limits the generalizability of the results. Fortunately, because of its cross-sectional characteristics and the handy availability of the web platform, the study is easily repeatable with an enhanced network.

Geographic information software programs' accuracy for interfacility air transport distances and time

INTRODUCTION

This study aimed to evaluate consistency/predictability of interfacility flight times (IFFTs) and accuracy of geographical information system (GIS) software packages for estimating IFFT.

METHODS

This retrospective study conducted by a program using a Bell 206 assessed the first 1000 IF transports occurring on 137 "runs" (ie, referring-receiving hospital pairings) made at least twice. GIS IFFT estimates using Google Earth™ (GE) and ArcGIS™ (AG) were compared against actual IFFT using linear regression; univariate analysis included assessment of medians with 95% binomial exact confidence intervals (CIs). Interrater agreement for GIS was assessed with κ.

RESULTS

GE and AG estimates fell, respectively, within 1 mile of actual in 136/137 runs (99%, 95% CI 96%-100%) and 130/137 runs (95%, 95% CI 90%-98%). GE- and AG-predicted IFFT strongly (P < .001) correlated with, underestimating by about 2 minutes, actual IFFT (GE: r2 0.93, coefficient 0.98, 95% CI .97-1.00; AG: r2 0.93; coefficient 0.98, 95% CI .96-1.0). GE and AG had statistically equivalent (κ > .8), "almost-perfect," interrater agreement.

CONCLUSION

IFFTs for same-run helicopter EMS transports in our rural state setting are characterized by little variability. GIS is highly accurate in predicting IF logistics, with public-domain GE performing as well as more expensive AG.

Impact of a physician-staffed helicopter on a regional trauma system: a prospective, controlled, observational study

INTRODUCTION

This study aims to compare the trauma system before and after implementing a physician-staffed helicopter emergency medical service (PS-HEMS). Our hypothesis was that PS-HEMS would reduce time from injury to definitive care for severely injured patients.

METHODS

This was a prospective, controlled, observational study, involving seven local hospitals and one level I trauma centre using a before and after design. All patients treated by a trauma team within a 5-month period (1 December 2009-30 April 2010) prior to and a 12-month period (1 May 2010-30 April 2011) after implementing a PS-HEMS were included. We compared time from dispatch of the first ground ambulance to arrival in the trauma centre for patients with Injury Severity Score (ISS) > 15. Secondary end points were the proportion of secondary transfers and 30-day mortality.

RESULTS

We included 1788 patients, of which 204 had an ISS > 15. The PS-HEMS transported 44 severely injured directly to the trauma centre resulting in a reduction of secondary transfers from 50% before to 34% after implementation (P = 0.04). Median delay for definitive care for severely injured patients was 218 min before and 90 min after implementation (P < 0.01). The 30-day mortality was reduced from 29% (16/56) before to 14% (21/147) after PS-HEMS (P = 0.02). Logistic regression showed PS-HEMS had an odds ratio (OR) for survival of 6.9 compared with ground transport.

CONCLUSIONS

Implementation of a PS-HEMS was associated with significant reduction in time to the trauma centre for severely injured patients. We also observed significantly reduced proportions of secondary transfers and 30-day mortality.

Helicopter emergency medical services crew administration of antibiotics for open fractures

This study had 3 major aims: (1) to ascertain the degree to which helicopter emergency medical services (HEMS) administration of antibiotics (Abx) can streamline the time to Abx in open fracture patients, (2) to determine whether any clinical outcome improvements were associated with HEMS Abx therapy, and (3) to calculate the cost-effectiveness of prehospital HEMS Abx. The design of the study was a prospective, nonrandomized, nonintervention, natural study of timing and clinical outcomes for patients with suspected open extremity fracture. There were 138 scene trauma cases transported by 8 participating HEMS programs from July 2009 to June 2010. The participating HEMS programs were both urban and rural. The diagnosis of an open fracture by the HEMS crews had an accuracy rate of 97.8% (95% confidence interval, 90.8%-98.4%). The time from the incident to Abx was 30 minutes shorter (P = .0001) when Abx were administered by HEMS crews. There was no statistical significance (P = 1.0) regarding the endpoint of infection or nonunion development in HEMS- versus hospital-administered Abx. In conclusion, the administration of Abx by HEMS crews to patients diagnosed with open extremity fractures is feasible, it may decrease the time to Abx by 30 minutes, and the effect magnitude (40.3% relative risk reduction) was promising.