Loss of life years due to unavailable helicopter emergency medical service: a single base study from a rural area of Norway

Natural Experiment Outcomes Studies in Rotor Wing Air Medical Transport: Systematic Review and Meta-Analysis of Before-and-After and Helicopter-Unavailable Publications From 1970 to 2022

OBJECTIVE

Helicopter emergency medical services (HEMS) is widely used for prehospital and interfacility transport, but there is a paucity of HEMS outcomes data from studies using randomized controlled trial designs. In the absence of robust randomized controlled trial evidence, judgments regarding HEMS potential benefit must be informed by observational data. Within the study design set of observational analyses, the natural experiment (NE) is notable for its high potential methodologic quality; NE designs are occasionally denoted "quasi-experimental." The aim of this study is to examine all NE outcomes studies in the HEMS literature and to discern what lessons can be learned from these potentially high-quality observational data.

METHODS

HEMS NE studies were identified during the development of a new HEMS Outcomes Assessment Research Database (HOARD). HOARD was constructed using a broad-ranging search of published and gray literature resources (eg, PubMed, Embase, and Google Scholar) that used variations of the terms "helicopter EMS," "air ambulance," and "air medical transport." Among the 221 studies ultimately included in HOARD, 16 NE publications describing 13 sets of observational data comprising myriad diagnostic groups were identified. Of these 16 HEMS NEs, 4 HEMS NE studies assessing trauma outcomes were used in a meta-analysis. A meta-analysis was also performed of 4 HEMS NE studies.

RESULTS

Although the disparity of studies (in terms of both case mix and end points) precluded the generation of a pooled effect estimate of an adjusted mortality benefit of HEMs versus ground emergency medical services, HEMS was found to be associated with outcomes improvement in 8 of the 13 cohorts.

CONCLUSION

The weight of the NE evidence supports a conclusion of some form of HEMS-mediated outcomes improvement in a variety of patient types. Meta-analysis of 4 HEMS NE studies assessing trauma outcomes generated a model with acceptable heterogeneity (I2 = 43%, Q test: P = .16), which significantly (P < .01) favored HEMS use with a pooled HEMS survival odd ratio estimate of 1.66 (95% confidence interval, 1.23-2.22).

Primary care doctors in acute call-outs to severe trauma incidents in Norway - associations with factors related to patients and doctors

OBJECTIVE

Severe trauma patients need immediate prehospital intervention and transfer to a specialised trauma hospital. In Norway, primary care doctors (PCDs) are an integrated part of the prehospital trauma care. The aim of this study was to investigate the degree to which PCDs were involved in prehospital care of severe trauma patients and how factors related to patients and doctors were associated with call-outs to these incidents.

DESIGN

This was a registry-based study in Norway on severe trauma patients with acute hospital admission during the period 2012-2018.

SETTING

Data was obtained from three Norwegian official registries.

SUBJECTS

By linking the registries, we studied the actions taken by the PCDs, whether they called out to severe trauma incidents.

MAIN OUTCOME MEASURES

In multivariable regression models, we investigated whether factors related to the PCDs (age, sex, specialisation in general practice (GP)) and patients (age, sex, duration of hospital stay, type of injury) were associated with call-outs.

RESULTS

Out of 4342 severe trauma incidents, PCDs had documented involvement in 1683 (39%) and called out to 644 (15%). Increased proportions of PCD call-outs to severe trauma incidents were significantly associated with lower age of PCD, being a GP specialist, lower patient age, being a male patient, increased length of hospital stay and injuries to the head and the neck.

CONCLUSIONS

PCDs called out to a relatively low proportion of severe trauma patients. Several factors related to patients and doctors were associated with call-outs to severe trauma incidents in Norway.

Survival Benefit of Helicopter Scene Response for Patients with an Injury Severity Score of at Least Nine: A Systematic Review and Meta-Analysis

BACKGROUND AND AIM

Helicopter EMS (HEMS) is a well-established mode of rapid transportation for patients with need for time-sensitive interventions, especially in patients with significant traumatic injuries. Traditionally in the setting of trauma, HEMS is often considered appropriate when used for patients with "severe" injury as defined by Injury Severity Score (ISS) >15. This may be overly conservative, and patients with a lower ISS may benefit from HEMS-associated speed or care quality. Our objective was to perform a meta-analysis of trauma HEMS transports to evaluate for possible mortality benefit in injured cases defined by an ISS score >8, lower than the customary ISS cutoff of >15.

METHODS

A broad search of the literature was performed including PubMed, EMBASE, SCOPUS, Cochrane Central Register of Controlled Trials, and Google Scholar from the years 1970 to 2022. The gray literature and reference lists of included publications were also examined. We included studies with the outcome of mortality in HEMS vs control in trauma transports from scene of injury for patients (adult or pediatric) with ISS > 8.

RESULTS

Nine eligible studies were used in the final analysis: six in the primary analysis and three in sensitivity analysis due to patient overlap. All studies reported statistically significant survival benefit in HEMS compared to control group. The minimum survival odds ratio (OR) benefit observed was OR 1.15 (95% CI 1.06-1.25) and maximum was OR 2.04 (95% CI 1.18-3.57). Risk of bias tool (ROBINS-I) application yielded moderate to low risk of bias, mainly due to the observational nature of the studies included.

CONCLUSIONS

There was a statistically significant survival benefit in patients with ISS > 8 when HEMS was used over traditional ground ambulance transportation, although novel and more inclusive trauma triage criteria may be more appropriate in the future to guide HEMS utilization decision-making. Restricting HEMS to trauma patients with ISS >15 likely misses survival benefit that could be afforded to the subset of trauma patients with serious injury.

Medical evacuations in Greenland in 2018: a descriptive study

Information regarding medical evacuations in Greenland is sparse. This study provides an overview of incidence, costs, and diagnoses leading to medical evacuations in Greenland in 2018. This is a retrospective, observational study. Patients with a valid Danish civil personal registration number were included. Data were obtained by scrutinising the itinerary of the Greenland travel coordination office and the medical records. 481 patients were identified. Forty-nine patients were excluded. 432 patients were analysed. Two-thirds of the evacuations were carried out within Greenland. The overall incidence of evacuations was 7.7 evacuations per 1,000 inhabitants per year. This differed, however, between the five different health regions. The cost of a medical evacuation ranged from less than 4,800 US dollars to more than 50,000 US dollars per case. Pregnancy and childbirth accounted for the majority of evacuations in women (31.2%) while diseases within the circulatory system and digestive tract accounted for the majority of evacuations in men (39.8%). The costs of medical evacuations may be reduced when combining evacuations of more than one patient. This indicates that combining evacuations of multiple patients from one health region by applying mandatory use of a central coordinating service may be beneficial.

Helicopter emergency medical services missions to islands and the mainland during a 3-year period in Denmark: a population-based study on patient and sociodemographic characteristics, comorbidity, and use of healthcare services

Background

The Danish Helicopter Emergency Medical Services (HEMS) is part of the Danish Emergency Medical Services System serving 5.7 million citizens with 1% living on islands not connected to the mainland by road. HEMS is dispatched based on pre-defined criteria including severity and urgency, and moreover to islands for less urgent cases, when rapid transport to further care is needed. The study aim was to characterize patient and sociodemographic factors, comorbidity and use of healthcare services for patients with HEMS missions to islands versus mainland.

Methods

Descriptive study of data from the HEMS database in a three-year period from 1 October 2014 to 30 September 2017. All missions in which a patient was either treated on scene or transported by HEMS were included.

Results

Of 5776 included HEMS missions, 1023 (17.7%) were island missions. In total, 90.2% of island missions resulted in patient transport by HEMS compared with 62.1% of missions to the mainland. Disease severity was serious or life-threatening in 34.7% of missions to islands compared with 65.1% of missions to mainland and less interventions were performed by HEMS on island missions. The disease pattern differed with more “Other diseases” registered on islands compared with the mainland where cardiovascular diseases and trauma were the leading causes of contact. Patients from islands were older than patients from the mainland. Sociodemographic characteristics varied between inhabiting island patients and mainland patients: more island patients lived alone, less were employed, more were retired, and more had low income. In addition, residing island patients had to a higher extend severe comorbidity and more contacts to general practitioners and hospitals compared with the mainland patients.

Conclusions

HEMS missions to islands count for 17.7% of HEMS missions and 90.2% of island missions result in patient transport. The island patients encountered by HEMS are less severely diseased or injured and interventions are less frequently performed. Residing island patients are older than mainland patients and have lower socioeconomic position, more comorbidities and a higher use of health care services. Whether these socio-economic differences result in longer hospital stay or higher mortality is still to be investigated.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13049-021-00963-6.

Characteristics of Emergency Neurological Patients Who Were Transported by Helicopter Emergency Medical Services in Tochigi, Japan

In Japan, reports on the association of individual characteristics, and geographical distance and time with clinical outcomes for neurological emergencies involving helicopter emergency medical services (HEMS) are scarce. Using Tochigi HEMS data (2010-2018), we assessed the characteristics of 1,170 emergency neurological patients (e.g., stroke, neurotrauma, and seizure) at the base hospital, which covered 58% of all HEMS patients in the prefecture. After initial treatment in the emergency room, emergency physicians confirmed the clinical outcomes of each patient compared to those at the incident sites (recovery/non-recovery). We calculated the geographic distance from the base hospital to each incident site, and estimated and adjusted odds ratios (aOR) and 95% confidence intervals (CI) for non-recovery against distance. The mean distance between the incident site and base hospital was 22.0 ± 11.7 km, and 77.4% of patients recovered following initial treatment. Two peak age groups were observed among emergency neurological diseases, including seizures in patients who were aged < 5 years and stroke and neurotrauma in patients who were aged 70-80 years. The percentages of stroke, traumatic head and brain injury, and seizure were 35.8%, 29.2%, and 22.8%, respectively. The incidence of stroke (aOR = 11.8, 95% CI 6.86-20.3) and neurotrauma (aOR = 4.86, 95% CI 2.78-8.51) independently predicted a poor prognosis. However, no significant association was observed with the distance from the base hospital. Therefore, in the Tochigi prefecture, geographical disparities may not affect the short-term prognosis of patients with neurological emergencies who were transported by HEMS.

Geospatial assessment of helicopter emergency medical service overtriage

BACKGROUND

Despite evidence of benefit after injury, helicopter emergency medical services (HEMS) overtriage remains high. Scene and transfer overtriage are distinct processes. Our objectives were to identify geographic variation in overtriage and patient-level predictors, and determine if overtriage impacts population-level outcomes.

METHODS

Patients 16 years or older undergoing scene or interfacility HEMS in the Pennsylvania Trauma Outcomes Study were included. Overtriage was defined as discharge within 24 hours of arrival. Patients were mapped to zip code, and rates of overtriage were calculated. Hot spot analysis identified regions of high and low overtriage. Mixed-effects logistic regression determined patient predictors of overtriage. High and low overtriage regions were compared for population-level injury fatality rates. Analyses were performed for scene and transfer patients separately.

RESULTS

A total of 85,572 patients were included (37.4% transfers). Overtriage was 5.5% among scene and 11.8% among transfer HEMS (p < 0.01). Hot spot analysis demonstrated geographic variation in high and low overtriage for scene and transfer patients. For scene patients, overtriage was associated with distance (odds ratio [OR], 1.03; 95% confidence interval [CI], 1.01-1.06 per 10 miles; p = 0.04), neck injury (OR, 1.27; 95% CI, 1.01-1.60; p = 0.04), and single-system injury (OR, 1.37; 95% CI, 1.15-1.64; p < 0.01). For transfer patients, overtriage was associated with rurality (OR, 1.64; 95% CI, 1.22-2.21; p < 0.01), facial injury (OR, 1.22; 95% CI, 1.03-1.44; p = 0.02), and single-system injury (OR, 1.35; 95% CI, 1.18-2.19; p < 0.01). For scene patients, high overtriage was associated with higher injury fatality rate (coefficient, 1.72; 95% CI, 1.68-1.76; p < 0.01); low overtriage was associated with lower injury fatality rate (coefficient, -0.73; 95% CI, -0.78 to -0.68; p < 0.01). For transfer patients, high overtriage was not associated with injury fatality rate (p = 0.53); low overtriage was associated with lower injury fatality rate (coefficient, -2.87; 95% CI, -4.59 to -1.16; p < 0.01).

CONCLUSION

Geographic overtriage rates vary significantly for scene and transfer HEMS, and are associated with population-level outcomes. These findings can help guide targeted performance improvement initiatives to reduce HEMS overtriage.

LEVEL OF EVIDENCE

Therapeutic, level IV.

Association of Helicopter vs Ground Emergency Medical Transportation With 1-Year Mortality in Denmark

IMPORTANCE

Appropriate use of helicopter emergency medical service (HEMS) is important in ensuring that patients with critical illness or injury receive adequate treatment.

OBJECTIVE

To investigate the association between use of HEMS compared with use of ground EMS (GEMS) and mortality overall and in a subgroup of patients with critical illness or injury.

DESIGN, SETTING, AND PARTICIPANTS

This register-based, nationwide cohort study used data retrieved from Danish registries from October 1, 2014, to April 30, 2018. Patients receiving GEMS originated from dispatched HEMS missions for which a helicopter was unavailable. For the primary analysis, patients from accepted HEMS missions and patients from missions in which HEMS was dispatched but unavailable were included. The secondary analysis included patients assigned a hospital International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10) diagnosis considered a critical illness or injury. These patients were selected via a consensus-based agreement among all authors by reviewing the Danish version of the World Health Organization's ICD-10 classification. Data were analyzed from March to June 2020.

EXPOSURES

Dispatch of HEMS vs GEMS unit (primary analysis) and treatment and transport by HEMS vs GEMS unit among patients with critical illness or injury (secondary analysis).

MAIN OUTCOMES AND MEASURES

One-year mortality was retrieved from the Danish Civil Registration System.

RESULTS

Among 10 618 patients (median [interquartile range] age, 60 [42-72] years; 6834 [64.4%] men) included in the primary analysis, 9480 patients (89.3%) received HEMS and 1138 patients (10.7%) received GEMS. Median (interquartile range) age was 60 (42-72) years, and 6834 patients (64.4%) were men. Adjusted cumulative 1-year mortality was 23.2% (95% CI, 22.4%-24.1%) among patients receiving HEMS vs 24.5% (95% CI, 21.9%-27.1%) among patients receiving GEMS. The difference in mortality risk for HEMS compared with GEMS was not statistically significant (hazard ratio, 0.94 [95% CI, 0.84-1.06]). Among 2260 patients with critical illness or injury receiving HEMS, compared with 315 patients with critical illness or injury receiving GEMS, adjusted cumulative 1-year mortality was 25.1% (95% CI, 23.5%-26.7%) vs 27.1% (95% CI, 22.0%-32.1%). The difference in mortality risk for HEMs compared with GEMs was not statistically significant (hazard ratio, 0.91 [95% CI, 0.73-1.14]).

CONCLUSIONS AND RELEVANCE

This study found that 1 year after dispatch, the use of HEMS, compared with the use of GEMS, was not associated with a statistically significant difference in mortality overall or mortality among patients with critical illness or injury. Further research is needed to determine whether optimized dispatch systems may be associated with further improvements in survival among selected patients.

Dispatch of a helicopter emergency medicine service to patients with a sudden, unexplained loss of consciousness of medical origin

Background

Sudden loss of consciousness (LOC) in the prehospital setting in the absence of cardiac arrest and seizure activity may be a challenge from a dispatcher’s perspective: The aetiology is varied, with many causes being transient and mostly self-limiting, whereas other causes are potentially life threatening. In this study we aim to evaluate the dispatch of HEMS to patients with LOC of medical origin, by exploring to which patients with a LOC HEMS is dispatched, which interventions HEMS teams perform in these patients, and whether HEMS interventions can be predicted by patient characteristics.

Methods

We performed retrospective cohort study of all patients with a reported unexplained LOC (e.g. not attributable to a circulatory arrest or seizures) attended by the Air Ambulance Kent, Surrey & Sussex (AAKSS), over a 4-year period (July 2013–December 2017). Primary outcome was defined as the number of HEMS-specific interventions performed in patients with unexplained LOC. Secondary outcome was the relation of clinical- and dispatch criteria with HEMS interventions being performed.

Results

During the study period, 127 patients with unexplained LOC were attended by HEMS. HEMS was dispatched directly to 25.2% of the patients, but mostly (74.8%) on request of the ground ambulance crews. HEMS interventions were performed in 65% of the patients (Prehospital Emergency Anaesthesia 56%, hyperosmolar therapy 21%, antibiotic/antiviral therapy 8%, vasopressor therapy 6%) and HEMS conveyed most patients (77%) to hospital. Acute neurological pathology was a prevalent underlying cause of unexplained LOC: 38% had gross pathology on their CT-scan upon arrival in hospital. Both GCS (r = − 0.60, p < .001) and SBP (r = 0.31, p < .001) were related to HEMS interventions being performed on scene. A GCS < 13 predicted the need for HEMS interventions in our population with a sensitivity of 94.9% and a specificity 75% (AUC 0.85).

Conclusion

HEMS dispatchers and ambulance personnel are able to identify a cohort of patients with unexplained LOC of medical origin who suffer from potentially life threatening (mainly neurological) pathology, in whom HEMS specific intervention are frequently required. Presenting GCS can be used to inform the triage process of patients with LOC at an early stage.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12873-020-00388-x.

Future development of helicopter emergency medical services in Korea

This paper discusses the future development of air ambulance operations in Korea. Helicopter emergency medical services are a useful means of transporting critically ill patients to the right hospital, at the right time. It is an important element of the emergency medical system to treat acute diseases at the scene, or in transit. For more efficient operations of the emergency medical helicopters (air ambulances or the so-called ‘Doctor Helgi’ in Korea), various challenges are faced. These include, the expansion of air ambulance bases, proper placement of rendezvous points (landing point), increase of field transport requests, and the operation of night missions. First, it is necessary to reduce the disparity in the benefits of emergency medical care for critically ill patients through the expansion of helicopter bases. Second, through the advancement of joint operations of the pan-ministerial emergency medical helicopters, the time from dispatch to helicopter take-off should be minimized, and a quality improvement program for air transportation should be carried out. Third, it is necessary to increase the number of insufficient rendezvous points and ensure the safety of the helicopters during takeoff and landing, to activate field transportation. Finally, the safety of patients and medical staff should be secured through the systematic preparation of the air transport system for future night missions. To solve these tasks, an appropriate legal system for helicopter emergency medical service is required. Based on the improved system, it is expected that everyone will enjoy equal rights for health, regardless of the regions.

Predicting Outcomes of Penetrating Cardiovascular Injuries at a Rural Center by Different Scoring Systems

OBJECTIVE

To compare the anatomical and physiological scoring systems and the outcomes of surgical management of penetrating cardiovascular trauma at a rural center.

METHODS

Seventy-seven patients underwent emergency surgery at our center between January/2012 and October/2018 due to penetrating cardiovascular trauma. Injury Severity Score (ISS), Revised Trauma Score (RTS), New Injury Severity Score (NISS), and Trauma and Injury Severity Score (TRISS) were calculated. The validation of these risk scores to predict mortality was assessed by the area under the receiver operating characteristic curve analysis.

RESULTS

All trauma scores were correlated with mortality. As ISS, NISS, and TRISS values increased and RTS values decreased, the mortality rate increased. The area under the curve (AUC) in the receiver operating characteristic curve analysis was 0.943 for TRISS, 0.915 for RTS, 0.890 for ISS, and 0.896 for NISS (P<0.001 for each). Logistic regression analysis revealed that scores were correlated with mortality (P<0.001 for each). By investigating cardiac injuries alone, only TRISS and RTS results correlated with mortality for cardiac injuries (Mann-Whitney U test, P=0.003 and P=0.01, respectively). The AUC was only statistically significant for TRISS and RTS (AUC=0.929, P<0.05 for both). For vascular injuries, all the scores were significantly correlated with in-hospital mortality (Mann-Whitney U test, P<0.001 for each). TRISS had the highest AUC (AUC=0.946, P<0.001).

CONCLUSION

TRISS has the highest predictivity for in-hospital mortality in patients with penetrating cardiovascular trauma.