Helicopter Emergency Medical Services Response Research Articles

Helicopter emergency medical services (HEMS) response to out-of-hospital cardiac arrest (OHCA) in the United States

IntroductionHelicopter emergency medical services (HEMS) are used in the United States and globally to respond to patients with critical illness and victims of traumatic injury. Relatively limited research has examined their role in responding to out-of-hospital cardiac arrests (OHCA) in the United States. In this study, we compared OHCA treated by HEMS units with cardiac arrests treated by ground ambulances. MethodsWe queried a large national-level database of emergency medical services (EMS) activations in the United States (NEMSIS). Inclusion criteria were OHCA activations between January 1, 2022 and December 31, 2022 treated by either HEMS or ground ambulance. Key arrest data from both groups were then compared. Interfacility transfers and cardiac arrests after EMS arrival were excluded. ResultsA total of 1,233 cardiac arrests treated by HEMS and 341,096 cardiac arrests treated by ground ambulances met inclusion criteria. Comparing the two groups, cardiac arrests with HEMS response were more likely to be male (66.7% vs. 62.8%, p < 0.01), White (50.2% vs. 45.7%, p < 0.01), under 18 years old (10.9% vs. 2.7%, p < 0.001), associated with traumatic injury (19.1% vs. 5.7%, p < 0.001), witnessed (72.7% vs. 37.3%, p < 0.001), and initially-shockable (24.7% vs. 11.1%, p < 0.001). ConclusionOur comparison of cardiac arrests treated by HEMS with cardiac arrests treated by ground ambulance reveals significant differences between the two groups. Further research is needed to better characterize HEMS’ ideal role in the response to OHCA as new prehospital resuscitative techniques for non-traumatic and traumatic cardiac arrest are developed.

The introduction of a regional Norwegian HEMS coordinator: an assessment of the effects on response times, geographical service areas and severity scores

BackgroundDue to unwanted delays and suboptimal resource control of helicopter emergency medical services (HEMS), regional HEMS coordinators have recently been introduced in Norway. This may represent an unnecessary link in the alarm chain, which could cause delays in HEMS dispatch. Systematic evaluations of this intervention are lacking. We wanted to conduct this study to assess possible changes in HEMS response times, mission distribution patterns and patient characteristics within our region following this intervention.MethodsWe retrospectively collected timeline parameters, patient characteristics and GPS positions from HEMS missions executed by three regional HEMS bases in Mid-Norway during 2017–2018 (preintervention) and 2019 (postintervention). The mean regional response time in HEMS missions was assessed by an interrupted time series analysis (ITS). The geographical mission distribution between regional HEMS resources was assessed by a before-after study with a convex hull-based method.ResultsThere was no significant change in the level (-0.13 min/month, p = 0.88) or slope (-0.13 min/month, p = 0.30) of the mean regional response time trend line pre- and postintervention. For one HEMS base, the service area was increased, and the median mission distance was significantly longer. For the two other bases, the service areas were reduced. Both the mean NACA score (4.13 ± SD 0.027 vs 3.98 ± SD 0.04, p < 0.01) and the proportion of patients with severe illness or injury (NACA 4–7, 68.2% vs 61.5%, p < 0.001) were higher in the postintervention group.ConclusionThe introduction of a regional HEMS coordinator in Mid-Norway did not cause prolonged response times in acute HEMS missions during the first year after implementation. Higher NACA scores in the patients treated postintervention suggest better selection of HEMS use.

Effect of time intervals in critical care provided by helicopter emergency medical services on 30-day survival after trauma

BackgroundTrauma is the leading cause of death especially in children and young adults. Prehospital care following trauma emphasizes swift transport to a hospital following initial care. Previous studies have shown conflicting results regarding the effect of time on the survival following major trauma. In our study we investigated the effect of prehospital time-intervals on 30-day mortality on trauma patients that received prehospital critical care. MethodsWe performed a retrospective study on all trauma patients encountered by helicopter emergency medical services in Finland from 2012 to 2018. Patients discharge diagnoses were classed into (1) trauma without traumatic brain injury, (2) isolated traumatic brain injury and (3) trauma with traumatic brain injury. Emergency medical services response time, helicopter emergency medical services response time, on-scene time and transport time were used as time-intervals and age, Glasgow coma scale, hypotension, need for prehospital airway intervention and ICD-10 based Injury Severity Score were used as variables in logistic regression analysis. ResultsMortality data was available for 4,803 trauma cases. The combined 30-day mortality was 12.1% (582/4,803). Patients with trauma without a traumatic brain injury had the lowest mortality, at 4.3% (111/2,605), whereas isolated traumatic brain injury had the highest, at 22.9% (435/1,903). Patients with both trauma and a traumatic brain injury had a mortality of 12.2% (36/295). Following adjustments, no association was observed between time intervals and 30-day mortality. DiscussionOur study revealed no significant association between different timespans and mortality following severe trauma in general. Trends in odds ratios can be interpreted to favor more expedited care, however, no statistical significance was observed. As trauma forms a heterogenous patient group, specific subgroups might require different approaches regarding the prehospital timeframes. Study typeprognostic/therapeutic/diagnostic test.

Rapid Ground Transport of Trauma Patients: A Moderate Distance From Trauma Center Improves Survival

BackgroundThere is debate within the emergency medical services (EMS) community over the value of calling a helicopter for trauma patients within a moderate distance/<45 min, of a trauma center. Helicopter EMS (HEMS) generally have a wider scope and more advanced training than the ground EMS (GEMS). GEMS, on the other hand, have the benefit of being able to immediately initiate rapid transport to the trauma center without the delay involved with HEMS flying to the scene, landing, and assuming patient care. MethodsWe retrospectively analyzed patients brought to a level I trauma center who were admitted with blunt traumatic injuries between 2010 and 2015 in the Trauma Quality Improvement Program database. Two analyses were performed, one in which the patient's reported initial scene vitals met criteria for step one of the Centers for Disease Control's 2011 National Field Triage Guidelines (NFTG) and the other in which the patient's initial scene vitals met those same guidelines and/or had a pulse greater than 110 beats per minute. Patients were categorized on scene to emergency department (ED) transport mode, either HEMS or GEMS. Inclusion criteria were a HEMS response time to the scene that was between 15 and 45 min with a transport time from the scene to the ED that was between 10 and 35 min or a GEMS transport time from the scene to the ED that was between 15 and 45 min. Statistical significance (P < 0.05) was established through logit regression. Mortality rates were then calculated within each transport mode–based population. ResultsFour hundred subjects were included in the analysis of patients meeting the first step of the NFTG, with 212 HEMS patients and 188 in the GEMS group. HEMS had a higher mortality rate at 0.184 and GEMS at 0.101, which was statistically significant (P = 0.019). When 606 subjects meeting the first step of the NFTG or with a pulse greater than 110 beats per minute were analyzed, the results were statistically significant (P < 0.001), with the HEMS category having a higher mortality rate at 0.154 and the GEMS category having a lower mortality at 0.056. ConclusionsOur data demonstrate that scene-to-ED time is paramount, and rapid ground transport should be used in blunt trauma patients when the scene is up to a moderate ground distance away from the trauma center and there would be a moderate-to-prolonged HEMS response time. In both analyses, hemodynamically unstable trauma patients had lower rates of mortality following ground transport. We recognize that there may be a subset of patients at these distances who could benefit from HEMS response, particularly if the flight crew can offer more advanced and specialized techniques; however, every effort should be made to minimize the scene-to-ED time, and HEMS response, scene, and transport time must be considered. This study only analyzed the patients within a moderate distance of the trauma center and at longer distances or in different environments; HEMS transport may indeed minimize the scene to ED time.

Canceled to Be Called Back: A Retrospective Cohort Study of Canceled Helicopter Emergency Medical Service Scene Calls That Are Later Transferred to a Trauma Center

IntroductionIn our trauma system, helicopter emergency medical services (HEMS) can be requested to attend a scene call for an injured patient before arrival by land paramedics. Land paramedics can cancel this response if they deem it unnecessary. The purpose of this study is to describe the frequency of canceled HEMS scene calls that were subsequently transferred to 2 trauma centers and to assess for any impact on morbidity and mortality. MethodsProbabilistic matching was used to identify canceled HEMS scene call patients who were later transported to 2 trauma centers over a 48-month period. Registry data were used to compare canceled scene call patients with direct from scene patients. ResultsThere were 290 requests for HEMS scene calls, of which 35.2% were canceled. Of those canceled, 24.5% were later transported to our trauma centers. Canceled scene call patients were more likely to be older and to be discharged home from the trauma center without being admitted. ConclusionThere is a significant amount of undertriage of patients for whom an HEMS response was canceled and later transported to a trauma center. These patients face similar morbidity and mortality as patients who are brought directly from scene to a trauma center.

Reporting Helicopter Emergency Medical Services in Major Incidents: A Delphi Study

ObjectiveResearch on helicopter emergency medical services (HEMS) in major incidents is predominately based on case descriptions reported in a heterogeneous fashion. Uniform data reported with a consensus-based template could facilitate the collection, analysis, and exchange of experiences. This type of database presently exists for major incident reporting at www.majorincidentreporting.net. This study aimed to develop a HEMS-specific major incident template. MethodsThis Delphi study included 17 prehospital critical care physicians with current or previous HEMS experience. All participants interacted through e-mail. We asked these experts to define data variables and rank which were most important to report during an immediate prehospital medical response to a major incident. Five rounds were conducted. ResultsIn the first round, the experts suggested 98 variables. After 5 rounds, 21 variables were determined by consensus. These variables were formatted in a template with 4 main categories: HEMS background information, the major incident characteristics relevant to HEMS, the HEMS response to the major incident, and the key lessons learned. ConclusionBased on opinions from European experts, we established a consensus-based template for reporting on HEMS responses to major incidents. This template will facilitate uniformity in the collection, analysis, and exchange of experience.

The Need for a UK Helicopter Emergency Medical Service by Night: A Prospective, Simulation Study

BackgroundMajor trauma commonly occurs at night. Helicopter emergency medical services (HEMS) can provide advanced prehospital care to victims of major trauma but do not routinely operate at night in the United Kingdom. We sought to prospectively examine the need for a night HEMS service in Kent, Surrey, and Sussex in the United Kingdom. MethodsA 4-month, prospective study was conducted (July 1, 2012-October 31, 2012). HEMS dispatch paramedics were present in the ambulance dispatch center and undertook simulated HEMS activations when a suitable case was identified. All trauma cases from the 4-month study period were collated. Five independent HEMS clinicians reviewed the simulated tasking and trauma cases and gave an opinion on whether the patient met HEMS activation criteria. ResultsA mission rate of 1 case per night was predefined as cost-effective. During the prospective study, 145 calls were identified by the HEMS dispatch paramedic as appropriate for an HEMS response. If HEMS had deployed to all 145 incidents, this would have resulted in an average mission rate of 1.2 activations per night. Two hundred eight incidents were identified as potentially appropriate for HEMS activation. Responding to all 208 incidents would have resulted in a mean activation rate of 1.7 per night. ConclusionThis study justifies the need for Kent, Surrey and Sussex Air Ambulance Trust to operate a service at night for a trial period, with an estimated average mission load of 1 per night spread over the entire night period. Further research is warranted to determine the potential impact of a night HEMS service on outcome from major trauma.

Medical Emergency Workload of a Regional UK HEMS Service

ObjectiveRegionalized trauma networks have been established in England to centralize specialist care at dedicated centers of excellence throughout the country. Helicopter emergency medical services (HEMS) in the West Midlands region have been redesigned to form an integrated component of such systems. The continued use of such valuable and scarce resources for medical emergencies requires evaluation. MethodsA retrospective review of mission data for a regional Air Ambulance Service in England over a two year period. ResultsMedical emergencies continue to contribute a large proportion of the overall workload of the service. Requirement for advanced interventions at the scene was rare, with less than 10% of patients attended by HEMS teams having care needs that fall beyond the scope of standard paramedic practice. ConclusionDynamic solutions are needed to ensure that HEMS support for cases of medical emergency are appropriately targeted to incidents in which clinical benefit is conferred to the patient. Intelligent tasking of appropriate resources has the potential to improve the HEMS response to medical emergencies while optimizing the availability of resources to respond to other incidents, most notably cases of major trauma.

Helicopter emergency medical services response to equestrian accidents

Horse riding is a common leisure activity associated with a significant rate of injury. Helicopter emergency medical services (HEMS) may be called to equestrian accidents. Accurate HEMS tasking is important to ensure appropriate use of this valuable medical resource. We sought to review HEMS response to equestrian accidents and identify factors associated with the need for HEMS intervention or transport of the patient to a major trauma centre. Retrospective case review of all missions flown by Kent, Surrey & Sussex Air Ambulance Trust over a 1-year period (1 July 2011 to 1 July 2012). All missions were screened for accidents involving a horse. Call details, patient demographics, suspected injuries, clinical interventions and patient disposition were all analysed. In the 12-month data collection period there were 47 equestrian accidents, representing ∼3% of the total annual missions. Of the 42 cases HEMS attended, one patient was pronounced life extinct at the scene. In 15 (36%) cases the patient was airlifted to hospital. In four (10%) cases, the patient underwent prehospital anaesthesia. There were no specific predictors of HEMS intervention. Admission to a major trauma centre was associated with the rider not wearing a helmet, a fall onto their head or the horse falling onto the rider. Equestrian accidents represent a significant proportion of HEMS missions. The majority of patients injured in equestrian accidents do not require HEMS intervention, however, a small proportion have life-threatening injuries, requiring immediate critical intervention. Further research is warranted, particularly regarding HEMS dispatch, to further improve accuracy of tasking to equestrian accidents.

Helicopter Emergency Medical Services Response Times in Norway: Do They Matter?

ObjectiveThe main objective of the Norwegian air ambulance service is to provide advanced emergency medicine to critically ill or severely injured patients. The government has defined a time frame of 45 minutes as the goal within which 90% of the population should be reached. The aims of this study were to document accurate flying times for rotor wing units to the scene and to determine the rates of acute primary missions in Norway. MethodsWe analyzed operational data from every acute primary mission from all air ambulance bases in Norway in 2011, focusing on the flying time taken to reach scene, the municipality requesting the flight, and the severity score data. ResultsA total of 5,805 acute primary missions were completed in Norway in 2011. The median flying time was 19 minutes (25%-75% percentiles: 13-28). The mean mission rate for the 17 bases was 7.5 (95% confidence interval, 7.4-7.8 per 10,000 inhabitants). The overall mean (standard deviation) National Committee on Aeronautics score for all missions was 4.07 (1.30). ConclusionThe government's expectation of serving the entire population via HEMS within 45 minutes appears to be achieved on a national level. However, vast differences remain in the flying times and rates between bases.

Logistical Concerns for Helicopter Emergency Medical Services Response to the Injured Police Officer

IntroductionAlthough infrequent, helicopter emergency medical services (HEMS) have been activated to transport police officers injured in the line of duty. The purpose of this study was to query current industry operating procedures in terms of law enforcement training and operations, specifically in terms of firearms restrictions and cotransport of injured officers and suspects. MethodsThis is a survey-based study of air medical emergency medical services program managers in 2010. Descriptive statistics and the Fisher exact test were used to analyze the results. ResultsFifty-eight programs (78.4%) reported transporting officers injured in the line of duty. Sixty-three respondents (85.1%) maintained a written policy addressing the presence of weapons aboard the aircraft; 58.8% of respondents replied that this restriction applied to sworn law enforcement personnel on active duty. Nearly a quarter of programs with written firearms policies have not informed the law enforcement agencies affected by these policies. Two programs reported having cotransported an injured officer and a suspect. ConclusionHEMS will continue to play an important role in the care and transportation of injured officers. HEMS programs may have specific policies that impact law enforcement operations. Open communication of these policies and interagency training are critical to effective interaction during high-stress incidents.

Ground Emergency Medical Services Requests for Helicopter Transfer of ST‐segment Elevation Myocardial Infarction Patients Decrease Medical Contact to Balloon Times in Rural and Suburban Settings

ST-segment elevation myocardial infarction (STEMI) care is time-dependent. Many STEMI patients require interhospital helicopter transfer for percutaneous coronary intervention (PCI) if ground emergency medical services (EMS) initially transport the patient to a non-PCI center. This investigation models potential time savings of ground EMS requests for helicopter EMS (HEMS) transport of a STEMI patient directly to a PCI center, rather than usual transport to a local hospital with subsequent transfer. Data from a multicenter retrospective chart review of STEMI patients transferred for primary PCI by a single HEMS agency over 12 months were used to model medical contact to balloon times (MCTB) for two scenarios: a direct-to-scene HEMS response and hospital rendezvous after ground EMS initiation of transfer. Actual MCTB median time for 36 hospital-initiated transfers was 160 minutes (range = 116 to 321 minutes). Scene response MCTB median time was estimated as 112 minutes (range = 69 to 187 minutes). The difference in medians was 48 minutes (95% confidence interval [CI] = 33 to 62 minutes). Hospital rendezvous MCTB median time was estimated as 113 minutes (range = 74 to 187 minutes). The difference in medians was 47 minutes (95% CI = 32 to 62 minutes). No patient had an actual MCTB time of less than 90 minutes; in the scene response and hospital rendezvous scenarios, 2 of 36 (6%) and 3 of 36 (8%), respectively, would have had MCTB times under 90 minutes. In this setting, ground EMS initiation of HEMS transfers for STEMI patients has the potential to reduce MCTB time, but most patients will still not achieve MCTB time of less than 90 minutes.

Helicopter emergency medical service in out-of-hospital cardiac arrest--a 10-year population-based study.

In 1988, Norway established a countrywide, physician staffed helicopter emergency medical service (HEMS). The medical benefit remains controversial. The aim of this study was to estimate the population incidence of HEMS involvement in out-of-hospital cardiac arrest, report the patient outcome and evaluate the contribution of HEMS to survival. We studied HEMS operations in central Norway (population 364,000) during a 10-year period (1988-1997). Missions were classified according to type and quality of intervention done by the primary care providers. HEMS witnessed cardiac arrests were not considered. Patient outcome was determined as survival to hospital discharge with cerebral performance category (CPC) score. The contribution made by HEMS in each survivor was assessed from the timing of return of spontaneous circulation (ROSC) and from subsequent need for advanced medical intervention. The relation between survival and HEMS response time was investigated by ordinal correlation. A total of 541 requests (14.9 per 100,000 inhabitants per year) were identified, of which 424 missions were completed. Overall survival to discharge was 36/541 (6.6%), yielding a population survival incidence of 1 per 100,000 per year. Ninety-five percent of survivors made a favourable cerebral outcome (CPC 1 or 2). General practitioners/ambulance personnel resuscitated 29 out of 36 survivors. The remainder achieved ROSC after HEMS arrival. Case by case, HEMS assistance was considered possibly important in 17 survivors. We found no relation between survival and HEMS response time (P=0.77). Survival following out-of-hospital cardiac arrest assisted by HEMS in this region is low, but not negligible. While primary care is most important, HEMS may possibly contribute to the additional survival of 0.19 to 0.46 patients per 100,000 per year. This benefit appears to be independent of HEMS response time.

Roles of a helicopter emergency medical service in mass casualty incidents

The Connecticut helicopter emergency medical service (HEMS) has responded to 12 mass casualty incidents (MCI) in two years. Eight were drills and four were actual events. An MCI response plan was instituted prior to the onset of the HEMS program. All MCIs were reviewed to determined actual victims, knowledge of MCI prior to lift-off, and roles of the HEMS. The actual roles were compared with the pre-established roles. The four actual MCIs (building expolosion, hotel fire, bus rollover and plane crash) were reviewed. Sixty-seven victims were involved. Prenotification occurred in one MCI. The roles of the HEMS in each MCI were: triage {n=4}, medical treatment {n=}, transport {n=3}, augmented response {n=1}, and air surveillance {n=0}. The roles of HEMS response to MCI should be well-defined prior to an event. Air medical benefits include response within a large geographic area, highest level of prehospital medical care, identification of trauma receiving hospitals, and facilitation of transport.

Mid-year report

The Connecticut helicopter emergency medical service (HEMS) has responded to 12 mass casualty incidents (MCI) in two years. Eight were drills and four were actual events.An MCI response plan was instituted prior to the onset of the HEMS program. All MCIs were reviewed to determined actual victims, knowledge of MCI prior to lift-off, and roles of the HEMS. The actual roles were compared with the pre-established roles. The four actual MCIs (building expolosion, hotel fire, bus rollover and plane crash) were reviewed. Sixty-seven victims were involved. Prenotification occurred in one MCI. The roles of the HEMS in each MCI were: triage {n=4}, medical treatment {n=}, transport {n=3}, augmented response {n=1}, and air surveillance {n=0}.The roles of HEMS response to MCI should be well-defined prior to an event. Air medical benefits include response within a large geographic area, highest level of prehospital medical care, identification of trauma receiving hospitals, and facilitation of transport.