Utilization Of Helicopter Emergency Medical Services Research Articles

Association of Geographic Distance and Hospital Characteristics With Use of Interhospital Transfer by Air: A Multicenter Retrospective Study

ObjectiveInterhospital transfer by air (IHTA) represents the majority of helicopter air ambulance transports in the United States, but the evaluation of what factors are associated with utilization has been limited. We aimed to assess the association of geographic distance and hospital characteristics (including patient volume) with the use of IHTA. MethodsThis was a multicenter, retrospective study of helicopter flight request data from 2018 provided by a convenience sample of 4 critical care transport medicine programs in 3 US census regions. Nonfederal referring hospitals located in the home state of the associated critical care transport medicine program and within 100 miles of the primary receiving facility in the region were included if complete data were available. We fit a Poisson principal component regression model incorporating geographic distance, the number of emergency department visits, the number of hospital discharges, case mix index, the number of intensive care unit beds, and the number of general beds and tested the association of the variables with helicopter emergency medical services utilization. ResultsA total of 106 referring hospitals were analyzed, 21 of which were hospitals identified as having a consistent request pattern. Using the hospitals with a consistent referral pattern, geographic distance had a significant positive association with flight request volume. Other variables, including emergency department visit volume, were not associated. Overall, the included variables offered poor explanatory power for the observed variation between referring facilities in the use of IHTA (r2 = 0.09). Predicted flights based on the principal component regression model for all referring hospitals suggested the majority of referring hospitals used multiple flight programs. ConclusionGeographic distance is associated with the use of IHTA. Unexpectedly, most basic hospital characteristics are not associated with the use of IHTA, and the degree of variation between referring facilities that is explained by patient volume is limited. The evaluation of nonhospital factors, such as the density and availability of critical care or advanced life support ground emergency medical services resources, is needed.

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

ObjectiveOne 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. MethodsA 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. ResultsA 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. ConclusionThe 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.

Effects of mode and time of EMS transport on the rate and distribution of dead on arrival among trauma population transported to ACSCOT-verified trauma centers in the United States.

Unintentional injury remains the leading cause of death for adults worldwide. We aimed to investigate the rates and distribution of dead on arrival (DOA) patients according to emergency medical services (EMS) mode of transport (MoT), EMS transport time (TT), injury severity score (ISS), and type of injury. This retrospective study utilized de-identified incident-based data from the American College of Surgeons Trauma Quality Improvement Program Participant Use File (ACS-TQIP PUF) dataset (2013-2018) to study Adult DOA patients. DOA was defined according to the data point, "arrived with no signs of life and did not recover". Patients with unknown vitals and patients with no EMS vitals at the scene (HR = 0, RR = 0, and SBP = 0) were excluded to identify DOAs who died during transport. The DOAs included for analysis were sorted into three groups based on injury severity score [low (ISS < 15), intermediate (ISS = 15-24), and severe (ISS ≥ 25)] and subdivided according to injury type (blunt vs. penetrating), EMS Mode of transport and transport times. Statistical significance was defined as p < 0.05. The majority of the evaluated 6030 adult DOA patients were male (73.3%) and 18-64 years of age (79.6%). Most patients sustained blunt injuries (58.2%), and the most common mechanism of injury was motor vehicle collisions (MVCs). Patients who traveled by helicopter EMS (HEMS) experienced less deaths than those traveling by ground EMS (GEMS) despite transporting more severely injured patients over longer time intervals. Median HEMS TTs were greater than their GEMS counterparts for blunt and penetrating injuries across all ISS groups but were associated with fewer deaths. Helicopter emergency medical service use with intermediate and severely injured patients with penetrating injuries is associated with a reduced number of DOAs. Future studies should prospectively investigate EMS performance to confirm the findings identified in this retrospective analysis. Additionally, other factors affecting pre-hospital EMS performance (e.g., geographic variations, weather-related characteristics, in-flight interventions/procedures) should be investigated. Finally, the results of this study highlight the need for standardized HEMS utilization triage criteria.

Association of Risk of Mortality in Pediatric Patients Transferred From Scene by Helicopter With Major But Not Minor Injuries.

Helicopter emergency medical services (HEMS) are used for 16% of pediatric trauma. National HEMS guidelines advised that triage criteria be standardized for pediatric patients. A national report found pediatric HEMS associated with decreased mortality compared with ground emergency medical services (GEMS) but did not control for transport time. We hypothesized that the rate of HEMS has decreased nationally and the mortality risk for HEMS to be similar when adjusting for transport time compared with GEMS. The Pediatric Trauma Quality Improvement Program (2014-2016) was queried for patients younger than 16 years transported by HEMS or GEMS. A multivariable logistic regression was used. From 25,647 patients, 4527 (17.7%) underwent HEMS. The rate of HEMS from scene decreased from 21.2% in 2014 to 18.2% in 2016. The rate of HEMS for minor trauma (Injury Severity Score <15) decreased from 14.9% in 2014 to 13.5% in 2016 and major trauma (Injury Severity Score > 15) from 38.4% in 2014 to 35.9% in 2016. After controlling for predictors of mortality and transport time, HEMS was associated with decreased risk of mortality for only those with major injuries transferred from scene (odds ratio, 0.48; 95% confidence interval, 0.26-0.88; P = 0.01) compared with GEMS. The rate of HEMS in pediatric trauma has decreased. However, there is room for improvement as 14% of those with minor trauma are transported by HEMS. Given the similar risk of mortality compared with GEMS, further development of guidelines that avoid the unnecessary use of HEMS appears warranted. However, utilization of HEMS for transport of pediatric major trauma should continue.

Helicopter Emergency Medical Services for Trauma: An Update

Helicopter emergency medical services (HEMS) have become a well-established component of most contemporary trauma systems throughout the world. HEMS is associated with significant costs, safety concerns, and potential inappropriate use. In this update, we briefly review the historical context, evidence for clinical effectiveness, and methods for ensuring proper utilization of HEMS. A recently validated prehospital triage score—the Air Medical Prehospital Triage (AMPT)—is reviewed. Examples of system improvements using evidence-based practices and adherence to both national and local utilization guidelines are also discussed. Appropriate triage for HEMS use remains an important goal for developed trauma systems. Although associated with significant costs and safety concerns, recent literature has highlighted the association of HEMS with improved outcomes for trauma patients.

Helicopter Emergency Medical Services Utilization

BackgroundThe decision to utilize HEMS is a complex process that involves many considerations. Professional associations and agencies have published guidelines to assist providers with decision making for the utilization of helicopter transport. Study ObjectiveDetermine if requests for HEMS align with recently published utilization guidelines. Study DesignA retrospective chart review was performed during a six-month period. Reviewers versed in Wisconsin HEMS Utilization, NAEMSP, and CAMTS guidelines determined if transport criteria were met. Charts were categorized according to whether or not criteria for each set of recommendations were followed. Results514 charts were reviewed; 439 consisted of completed patient transports. CAMTS, NAEMSP, and WI HEMS guidelines satisfied 85.4%, 83.4%, and 53.1% of requests, respectively. Statistically significant differences existed when comparing rates meeting criteria between WI HEMS and CAMTS and between WI HEMS and NAEMSP guidelines (p-value <0.0001). This was true in all subgroups except STEMI, which did not show significant difference. No difference existed between rates for CAMTS and NAEMSP guidelines in any group. ConclusionSignificant difference between Wisconsin HEMS utilization versus NAEMSP guidelines, and between Wisconsin HEMS utilization and CAMTS guidelines in all subgroups except STEMI patients exist. No statistically significant difference existed between NAEMSP and CAMTS guidelines.

Disparities in Inter-hospital Helicopter Transportation for Hispanics by Geographic Region: A Threat to Fairness in the Era of Thrombectomy

Background and Purpose: Mechanical thrombectomy (MT) is a time-dependent therapy that is only available at a limited number of hospitals. As such, patients that live at a considerable distance of those specialized centers often require rapid interhospital emergent evacuation with Helicopter Emergency Medical Services (HEMS) to be considered for MT. It is not known whether the use of HEMS is equitable across different groups of patients. Methods: Acute ischemic stroke patients emergently transferred to another facility were identified in a retrospective review of a large Medicare claims database. Mode of transportation (HEMS, advanced, or basic ground ambulances) was determined by CPT codes. Distance from patient's residence to the closest center with MT capabilities was calculated. Generalized linear mixed logit models were used to determine the odds of HEMS relative to ground services for Hispanic and non-Hispanic black (NHB) patients relative to non-Hispanic white (NHW) patients while controlling for confounders. Results: A total of 8027 patients that underwent emergent interhospital transportation were analyzed. HEMS utilization was 18.1% for NHB, 20.6% for Hispanics, and 21.6% for NHW (P = .054). In adjusted analyses for confounders, including distance to a MT-capable hospital, Hispanic patients were less likely than NHWs to be transported by HEMS. While that association had marginal significance for the whole United States (OR = .76; 95% CI, .57-1.01; P = .055), it was statistically significant for patients living in the southern region of the United States (OR = .6; 95% CI, .40-.92; P = .019). Discussion: Our findings suggest there is a disparity in the use of HEMS in Hispanic stroke patients compared to NHW. Such a disparity may delay arrival to a MT-capable hospital, delay treatment times, or lead to ineligibility for MT altogether. Given the known benefit of MT and known existing disparities in stroke treatment and outcomes, it is important to further investigate and address disparities in mode of interhospital transportation.

Appropriate and Safe Utilization of Helicopter Emergency Medical Services: A Joint Position Statement with Resource Document

This position statement with accompanying resource document is the result of a collaborative effort of a writing group comprised of members of the Air Medical Physician Association (AMPA), the American College of Emergency Physicians (ACEP), the National Association of EMS Physicians (NAEMSP), and the American Academy of Emergency Medicine (AAEM). This document has been jointly approved by the boards of all four organizations.Patients benefit from the appropriate utilization of helicopter emergency medical services (HEMS). EMS and regional health care systems must have and follow guidelines for HEMS utilization to facilitate proper patient selection and ensure clinical benefit. Clinical benefit can be provided byMeaningfully shortening the time to delivery of definitive care to patients with time-sensitive medical conditionsProviding necessary specialized medical expertise or equipment to patients before and/or during transportProviding transport to patients inaccessible by other means of transportThe decision to use HEMS is a medical decision, separate from the aviation determination whether a transport can be completed safely.Physicians with specialized training and experience in EMS and air medical transport must be integral to HEMS utilization decisions, including guideline development and quality improvement activities.Safety management systems must be developed, adopted, and adhered to by air medical operators when making decisions to accept and continue every HEMS transport.HEMS must be fully integrated within the local, regional, and state emergency health care systems.HEMS programs cannot operate independently of the surrounding health care environment.The EMS and health care systems must be involved in the determination of the number of HEMS assets necessary to provide appropriate coverage for their region. Excessive resources may lead to competitive practices that can affect utilization and negatively impact safety. Inadequate resources will delay receipt of definitive care.National guidelines for appropriate utilization of HEMS must be developed. These guidelines should be national in scope yet allow local, regional, and state implementation.A National HEMS Agenda for the Future should be developed to address HEMS utilization and availability and to identify and support a research strategy for ongoing, evidence-based refinement of utilization guidelines. Key words: appropriateness; helicopter; HEMS; safety; utilization

Helicopter EMS beyond Trauma: Utilization of Air Transport for Non-Trauma Conditions

Helicopter Emergency Medical Services (HEMS) use in civilian medical transport has its roots in the use of rotor-wing trauma transport in the military setting. Much of the literature and evidence based on the use of HEMS is therefore related to scene and interfacility transport of injured patients. Regionalization of care and increased understanding of time-criticality of various non-trauma conditions has contributed to growing utilization of HEMS for non-trauma conditions over recent decades. It is common for HEMS to be utilized for a variety of non-trauma situations ranging from neonatal and obstetrics transports to cardiac and stroke transports. The purpose of this review is to overview the use of HEMS for non-trauma, focusing on situations in which there is evidence addressing possible HEMS utility.

Helicopter Emergency Medical Services Utilization for Winter Resort Injuries

Introduction. Helicopter and ground emergency medical services (EMS) units are frequently called to transport patients from winter resorts to area trauma centers. Objective. The purpose of this study was to examine helicopter EMS (HEMS) utilization for such patients, and to investigate out-of-hospital clinical variables that might help providers determine the most appropriate utilization of HEMS. Methods. The study included patients aged ≥12 years who were transported by ground EMS (GEMS) or HEMS to a regional trauma center with an acute injury sustained at a winter resort. The decision to transport via HEMS was based on field provider judgment. Injury information was prospectively obtained and combined with emergency department (ED) and hospital data abstracted from trauma registry and hospital records. For the purpose of this study, appropriate HEMS utilization was defined according to two different schemes. Limited utilization of HEMS was defined as the need for an emergent ED or out-of-hospital intervention (intubation, chest tube or needle thoracostomy, central line placement, or cardiopulmonary resuscitation). Expanded utilization of HEMS was defined as the need for an emergent intervention and/or an Injury Severity Score (ISS) ≥16 and/or need for emergent nonorthopedic surgery. Provider judgment alone was compared with results of recursive partitioning to predict the need for HEMS. Results. Of 815 patients enrolled between 2006 and 2009, 65 (8.0%) patients met the expanded criteria for appropriate HEMS utilization. Of these, 30 (46.2%) were transported by GEMS and 35 (53.8%) were transported by HEMS. Twenty-seven of the 65 patients (41.5%) required an emergent ED or out-of-hospital intervention. Activation of HEMS by out-of-hospital providers was (at best) 55.6% sensitive and 89.1% specific (85.2% overtriage rate) for predicting the need for an emergent out-of-hospital or ED intervention. Recursive partitioning, using a Glasgow Coma Scale score (GCS) ≤13 or pulse oximetry value <89%, was superior to provider judgment in predicting the need for an emergent procedure (57.9% sensitive, 98.6% specific, 45% overtriage rate). Conclusion. Use of a simple prediction rule was superior to provider judgment in predicting the need for an emergent ED or out-of-hospital procedure in patients injured at winter resorts. If validated, this rule may be a resource to help out-of-hospital providers decide when to activate HEMS in these unique areas.

Automatic helicopter standby policy for seriously injured patients.

Automatic standby (AS) of helicopter emergency medical services (HEMS) may allow improved utilization appropriateness (UA) for scene trauma, although this has not been studied. HEMS records were reviewed for 16 months, including date, county of origin, and UA. Data were analyzed descriptively with chi(2) where appropriate. Of 274 flights, there was no significant change in UA where AS was in place versus where it was not (P =.36). One county had an increase in total flights with AS in use without a significant change in UA (P =.10). In this region, use of an AS policy for scene trauma resulted in increased utilization of HEMS without a corresponding change in UA. Specifically, inappropriate utilization did not increase. This finding suggests that such a policy does not incur overutilization despite increasing total flights. Further study with larger numbers is necessary to draw definitive conclusions.

Automatic Helicopter Standby Policy for Seriously Injured Patients

Background: Automatic standby (AS) of helicopter emergency medical services (HEMS) may allow improved utilization appropriateness (UA) for scene trauma, although this has not been studied. Methods: HEMS records were reviewed for 16 months, including date, county of origin, and UA. Data were analyzed descriptively with χ 2 where appropriate. Results: Of 274 flights, there was no significant change in UA where AS was in place versus where it was not ( P = .36). One county had an increase in total flights with AS in use without a significant change in UA ( P = .10). Conclusion: In this region, use of an AS policy for scene trauma resulted in increased utilization of HEMS without a corresponding change in UA. Specifically, inappropriate utilization did not increase. This finding suggests that such a policy does not incur overutilization despite increasing total flights. Further study with larger numbers is necessary to draw definitive conclusions.

Helicopter trauma transport: an overview of recent outcomes and triage literature

The purpose of this review is to assess literature pertinent to outcomes benefits accrued by the use of helicopter emergency medical services for trauma transport. A previous annotated bibliography assessed literature published between 1980 and 2000. The goal of this paper is to address developments since fall 2001, and to cast recent studies in the light of earlier work in an attempt to provide a long-range overview of the relevant literature. In the year covered by this review, we identified four papers that directly assessed the association between the helicopter emergency medical services utilization and trauma outcome, and three that addressed the closely related issue of the helicopter emergency medical services triage appropriateness. An Italian study found no benefit associated with advanced prehospital care for patients with severe head injury. A US multicenter trial assessing blunt trauma transports found a substantial mortality reduction associated with helicopter use. Two other US studies, characterized by a similar 'natural experiment' design of assessing mortality changes on either side of a timepoint at which the helicopter emergency medical services availability ceased, reached opposite conclusions about the benefits of the service. Recent studies addressing the helicopter emergency medical services utilization in terms of triage were characterized by varying levels of agreement with the widely held belief that this service is characterized by overtriage. The preponderance of recent and previously extant evidence supports an argument that the helicopter emergency medical services transport is associated with significant benefit for some injured patients. The primary challenges at this time include the determination of which patients benefit and the elucidation of which aspects of the helicopter emergency medical services are responsible for any salutary effects of its utilization.

T RAUMA H ELICOPTER E MERGENCY M EDICAL S ERVICES T RANSPORT : A NNOTATED R EVIEW OF S ELECTED O UTCOMES-RELATED L ITERATURE

Based on its roots in military air evacuation, helicopter emergency medical services (HEMS) has always been emphasized as a tool for trauma transportation. Despite much discussion regarding resource allocation for HEMS, a literature search found little recent systematic review of pertinent studies. As HEMS utilization is subject to increased scrutiny in a health care dollar-conscious environment, it was felt that a compendium of available outcomes-related literature could assist those assessing utility of HEMS trauma transport. The current study utilized a Medline search to identify outcomes studies relative to HEMS trauma transport. The goal of this review is to provide a useful resource for those interested in pursuing systematic review of the HEMS trauma outcomes literature. The primary purpose of the review is bibliographic, but there is editorial comment after each paper's summary. The initial article in this two-part series focused on HEMS outcomes literature covering noninjured patients as well as papers assessing outcome in mixed trauma-nontrauma HEMS study groups.

N ONTRAUMA H ELICOPTER E MERGENCY M EDICAL S ERVICES T RANSPORT : A NNOTATED R EVIEW OF S ELECTED O UTCOMES - RELATED L ITERATURE

While helicopter emergency medical services (HEMS) has its roots in military transport of wounded soldiers, rotor-wing transport is also used for a wide variety of nontrauma indications. Despite this common use of HEMS for noninjured patients, a Medline search found little systematic review of the literature pertinent to HEMS use for nontrauma. With HEMS utilization subject to appropriately increased scrutiny, those seeking to research HEMS utility in noninjured patients could benefit from existence of a collection of the topical literature. This paper aims to provide such a review, in the form of an annotated bibliography of Index Medicus journal studies assessing potential medical risks and benefits of HEMS transport for noninjured patients. The paper's goal is to provide a useful resource for those interested in pursuing more focused review of various sectors of the nontrauma HEMS literature. As such, the main objective of the article summaries is to provide a brief outline of study design and results; there is also limited editorial comment included after each summary.

Utilization prediction for helicopter emergency medical services

As the number of helicopter emergency medical services (HEMS) programs continues to expand rapidly, the need for an accurate, readily obtainable, inexpensive method of utilization prediction for these services has become apparent. Accurate volume and case mix prediction for these services are increasingly important as financial constraints become more severe. All previous methods of utilization prediction based on experiences of individual services or accident statistics have been either inaccurate, costly, or difficult to obtain in a relatively short period of time. Prediction of HEMS utilization requires consideration of many significant, simultaneous factors, in addition to patient needs based on population statistics. Through use of a survey of all hospital-based helicopter emergency service programs and published census data, this study analyzed factors relating to helicopter program volume and case mix, providing insight as to why previous methods utilizing total population were inaccurate. A more accurate yet simple and inexpensive method of utilization prediction for HEMS was developed.