OBJECTIVE: Emergency medical services (EMS) providers transiently ascend to high altitude for primary missions and secondary transports in mountainous areas in helicopters that are unpressurised and do not have facilities for oxygen supplementation. The decrease in cerebral oxygen saturation can lead to impairment in attention and reaction time as well as in quality of care during acute exposure to altitude.
OBJECTIVE: The primary aim of the current study was to investigate the effect of oxygen supplementation on cognitive performance in Helicopter EMS (HEMS) providers during acute exposure to altitude.
METHODS: This interventional, randomized, controlled, double-blind, cross-over clinical trial was conducted in October 2021. Each trial used a simulated altitude scenario equivalent to 4000 m, in which volunteers were exposed to hypobaric hypoxia with a constant rate of ascent of 4 m/s in an environmental chamber under controlled, replicable, and safe conditions. Trials could be voluntarily terminated at any time. Inclusion criteria were being members of emergency medical services and search and rescue services with an age between 18 and 60 years and an American Society of Anesthesiologists physical status class I.
METHODS: Each participant conducted 2 trials, one in which they were exposed to altitude with oxygen supplementation (intervention trial) and the other in which they were exposed to altitude with ambient air supplementation (control trial).
METHODS: Measurements included peripheral oxygen saturation (SpO2), cerebral oxygenation (ScO2), breathing and heart rates, Psychomotor Vigilance Test (PVT), Digit-Symbol Substitution Test (DSST), n-Back test (2-BACK), the Grooved Pegboard test, and questionnaires on subjective performance, stress, workload, and positive and negative affect. Paired t-tests were used to compare conditions (intervention vs. control). Data were further analyzed using generalized estimating equations (GEE).
RESULTS: A total of 36 volunteers (30 men; mean [SD] age, 36 [9] years; mean [SD] education, 17 [4] years) were exposed to the intervention and control trials. The intervention trials, compared with the control trials, had higher values of SpO2 (mean [SD], 97.9 [1.6] % vs. 86 [2.3] %, t-test, p = 0.004) and ScO2 (mean [SD], 69.9 [5.8] % vs. 62.1 [5.2] %, paired t-test, p = 0.004). The intervention trials compared with the control trials had a shorter reaction time (RT) on the PVT after 5 min (mean [SD], 277.8 [16.7] ms vs. 282.5 [15.3] ms, paired t-test, p = 0.006) and after 30 min (mean [SD], 276.9 [17.7] ms vs. 280.7 [15.0] ms, paired t-test, p = 0.054) at altitude. While controlling for other variables, there was a RT increase of 0.37 ms for each % of SpO2 decrease. The intervention trials showed significantly higher values for DSST number of correct responses (with a difference of mean [SD], 1.2 [3.2], paired t-test, p = 0.035). Variables in the intervention trials were otherwise similar to those in the control trials for DSST number of incorrect responses, 2-BACK, and the Grooved Pegboard test.
CONCLUSIONS: This randomized clinical trial found that oxygen supplementation improves cognitive performance among HEMS providers during acute exposure to 4000 m altitude. The use of oxygen supplementation may allow to maintain attention and timely reaction in HEMS providers. The impact of repeated altitude ascents on the same day, sleep-deprivation, and additional stressors should be investigated. Trial registration NCT05073406, ClinicalTrials.gov trial registration.

Background/Objectives: The impacts of the coronavirus disease 2019 (COVID-19) pandemic on patients using helicopter emergency medical services (HEMS) regarding tracheal intubation and patient management remain unclear. Thus, we aimed to investigate this matter in Japan. Methods: In this retrospective, observational study, we analyzed 2277 patients who utilized HEMS in Tochigi Prefecture during 2018-2022. We included only patients who required tracheal intubation. We categorized patients from February 2020 to January 2022 in the pandemic group and those from February 2018 to January 2020 in the control group. We compared the interval from arrival at the scene to leaving the scene (on-scene time) and secondary variables between the two groups. Results: A total of 278 eligible patients were divided into the pandemic group (n = 127) and the control group (n = 151). The on-scene time was lower during the pandemic than that before (25.64 ± 9.19 vs. 27.83 ± 8.74 min, p = 0.043). The percentage of patients using midazolam was lower (11.8% vs. 22.5%, p = 0.02) and that of patients using rocuronium bromide was higher (29.1% vs. 6.0%, p < 0.001) during the pandemic. In contrast, the type of intervention other than tracheal intubation and the type of transportation to the hospital did not differ between the groups. Conclusions: The COVID-19 pandemic was associated with changes in the mission time of and the frequency of certain drugs administered by the HEMS. However, the type of intervention and the type of transportation did not differ. Further research is needed on changes in patient prognosis and condition due to the effects of the COVID-19 pandemic.

OBJECTIVE: Since Helicopter Emergency Medical Services (HEMS) is an expensive resource in terms of unit price compared to ground-based Emergency Medical Service (EMS), it is important to further investigate which methods would allow for the optimization of these services. The aim of this study was to evaluate the cost-effectiveness of physician-staffed HEMS compared to ground-based EMS in developed scenarios with improvements in triage, aviation performance, and the inclusion of ischemic stroke patients.
METHODS: Incremental cost-effectiveness ratio (ICER) was assessed by comparing health outcomes and costs of HEMS versus ground-based EMS across six different scenarios. Estimated 30-day mortality and quality-adjusted life years (QALYs) were used to measure health benefits. Quality-of-Life (QoL) was assessed with EuroQoL instrument, and a one-way sensitivity analysis was carried out across different patient groups. Survival estimates were evaluated from the national FinnHEMS database, with cost analysis based on the most recent financial reports.
RESULTS: The best outcome was achieved in Scenario 3.1 which included a reduction in over-alerts, aviation performance enhancement, and assessment of ischemic stroke patients. This scenario yielded 1077.07-1436.09 additional QALYs with an ICER of 33,703-44,937 €/QALY. This represented a 27.72% increase in the additional QALYs and a 21.05% reduction in the ICER compared to the current practice.
CONCLUSIONS: The cost-effectiveness of HEMS can be highly improved by adding stroke patients into the dispatch criteria, as the overall costs are fixed, and the cost-effectiveness is determined based on the utilization rate of capacity.

Aeromedical transport (AMT) is an integral part of healthcare systems worldwide. In this article, the personnel and equipment required, associated safety considerations, and evidence supporting the use of AMT is reviewed, with an emphasis on helicopter emergency medical services (HEMS). Indications for HEMS as guideded by the Air Medical Prehospital Triage Score are presented. Lastly, physiologic considerations, which are important to both AMT crews and receiving clinicians, are reviewed.

UNASSIGNED: Helicopter 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.
UNASSIGNED: We 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.
UNASSIGNED: A 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).
UNASSIGNED: Our 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.

BACKGROUND: In Finland, the yearly number of mechanical thrombectomies for acute stroke is increasing and more patients are transported over 100 km to the comprehensive stroke centre (CSC) for definitive care. This leaves the rural townships without immediate emergency medical services (EMS) for hours. In this study we compare the EMS\' estimated return times to own station after the handover of a thrombectomy candidate between two transport methods: (1) using ground transportation with an ambulance to the CSC or (2) using a hydrid strategy starting the transportation with an ambulance and continuing by air with a helicopter emergency medical services unit (HEMS).
METHODS: We reviewed retrospectively all thrombectomy candidates\' transportations from the hospital district of South Ostrobothnia to definitive care at the nearest CSC, Tampere University Hospital from June 2020 to October 2022. The dispatch protocol stated that a thrombectomy candidate\'s transport begins immediately with an ambulance and if the local HEMS unit is available the patient is handed over to them at a rendezvous. If not, the patient is transported to the CSC by ground. Transport times and locations of the patient handovers were reviewed from the CSC\'s EMS database and the driving time back to ambulance station was estimated using Google maps. The HEMS unit\'s pilot\'s log was reviewed to assess their mission engagement time.
RESULTS: The median distance from the CSC to the ambulances\' stations was 188 km (IQR 149-204 km) and from the rendezvous with the HEMS unit 70 km (IQR 51-91 km, p < 0.001). The estimated median driving time back to station after the patient handover at the CSC was 145 min (IQR 117-153 min) compared to the patient handover to the HEMS unit 53 min (IQR 38-68 min, p < 0.001). The HEMS unit was occupied in thrombectomy candidate\'s transport mission for a median of 136 min (IQR 127-148 min).
CONCLUSIONS: A hybrid strategy to transport thrombectomy candidates with an ambulance and a helicopter reallocates the EMS resources markedly faster back to their own district.

OBJECTIVE: For optimal prehospital trauma care, it is essential to adequately recognize potential life-threatening injuries in order to correctly triage patients and to initiate life-saving measures. The aim of the present study was to determine the accuracy of prehospital diagnoses suspected by helicopter emergency medical services (HEMS).
METHODS: This retrospective multicenter study included patients from the Swiss Trauma Registry with ISS ≥ 16 or AIS head ≥ 3 transported by Switzerland\'s largest HEMS and subsequently admitted to one of twelve Swiss trauma centers from 01/2020 to 12/2020. The primary outcome was the comparison of injuries suspected prehospital with the final diagnoses obtained at the hospital using the abbreviated injury scale (AIS) per body region. As secondary outcomes, prehospital interventions were compared to corresponding relevant diagnoses.
RESULTS: Relevant head trauma was the most commonly injured body region and was identified in 96.3% (95% CI: 92.1%; 98.6%) of the cases prehospital. Relevant injuries to the chest, abdomen, and pelvis were also common but less often identified prehospital [62.7% (95% CI: 54.2%; 70.6%), 45.5% (95% CI: 30.4%; 61.2%), and 61.5% (95% CI: 44.6%; 76.6%)]. Overall, 7 of 95 (7.4%) patients with pneumothorax received a chest decompression and in 22 of 39 (56.4%) patients with an instable pelvic fracture a pelvic binder was applied prehospital.
CONCLUSIONS: Approximately half of severe chest, abdominal, and pelvic diagnoses made in hospital went undetected in the challenging prehospital environment. This underlines the difficult circumstances faced by the rescue teams. Potentially life-saving interventions such as prehospital chest decompression and increased use of a pelvic binder were identified as potential improvements to prehospital care.

BACKGROUND: Recently, the Norwegian Helicopter Emergency Medical Service (HEMS) has developed a procedure for a special type of static rope rescue operation, referred to as the offset technique. In this technique, the helicopter is offset from the accident site, and the HEMS technical crew member uses an offset throw line to gain access to the scene. Today, there is little practical experience of such operations, and a need has been identified for more knowledge on the potential hazards encountered during this type of operation. Such knowledge is of importance for further development of the procedure for the offset technique.
OBJECTIVE: To identify potential hazards for helicopter rescue operations using the static rope offset technique and, thereby, to improve the procedure for such operations. This may lead to improved safety for patients and crew members during offset rescue operations.
METHODS: A Safe Job Analysis was used to identify the hazards of offset rescue operations. Such operations are divided into tasks and sub-tasks. For each sub-task, we identified potential hazards and suggested ways of preventing these.
RESULTS: Through the Safe Job Analysis, we suggest some changes in the existing procedure for the offset technique, to make it more robust against potential hazards.
CONCLUSIONS: We have demonstrated the value of Safe Job Analysis for improving the static rope offset evacuation procedure. Our analysis has led to some changes in the procedure for offset rescue operations. This is the importance of having two throw lines and focusing on \"why\" in the procedure.

BACKGROUND: Accurate haemodynamic monitoring in the prehospital setting is essential. Non-invasive blood pressure measurement is susceptible to vibration and motion artefact, especially at extremes of hypotension and hypertension: invasive arterial blood pressure (IABP) monitoring is a potential solution. This study describes the largest series to date of cases of IABP monitoring being initiated prehospital.
METHODS: This retrospective observational study was conducted at East Anglian Air Ambulance (EAAA), a UK helicopter emergency medical service (HEMS). It included all patients attended by EAAA who underwent arterial catheterisation and initiation of IABP monitoring between 1st February 2015 and 20th April 2023. The following data were retrieved for all patients: sex; age; aetiology (medical cardiac arrest, other medical emergency, trauma); site of arterial cannulation; operator role (doctor/paramedic); time of insertion and, where applicable, times of pre-hospital emergency anaesthesia, and return of spontaneous circulation following cardiac arrest. Descriptive analyses were performed to characterise the sample.
RESULTS: 13,556 patients were attended: IABP monitoring was initiated in 1083 (8.0%) cases, with a median age 59 years, of which 70.8% were male. 546 cases were of medical cardiac arrest: in 22.4% of these IABP monitoring was initiated during cardiopulmonary resuscitation. 322 were trauma cases, and the remaining 215 were medical emergencies. The patients were critically unwell: 981 required intubation, of which 789 underwent prehospital emergency anaesthesia; 609 received vasoactive medication. In 424 cases IABP monitoring was instituted en route to hospital.
CONCLUSIONS: This study describes over 1000 cases of prehospital arterial catheterisation and IABP monitoring in a UK HEMS system and has demonstrated feasibility at scale. The high-fidelity of invasive arterial blood pressure monitoring with the additional benefit of arterial blood gas analysis presents an attractive translation of in-hospital critical care to the prehospital setting.

BACKGROUND: Use of bystander video livestreaming from scene to Emergency Medical Services (EMS) is becoming increasingly common to aid decision making about the resources required. Possible benefits include earlier, more appropriate dispatch and clinical and financial gains, but evidence is sparse.
METHODS: A feasibility randomised controlled trial with an embedded process evaluation and exploratory economic evaluation where working shifts during six trial weeks were randomised 1:1 to use video livestreaming during eligible trauma incidents (using GoodSAM Instant-On-Scene) or standard care only. Pre-defined progression criteria were: (1) ≥ 70% callers (bystanders) with smartphones agreeing and able to activate live stream; (2) ≥ 50% requests to activate resulting in footage being viewed; (3) Helicopter Emergency Medical Services (HEMS) stand-down rate reducing by ≥ 10% as a result of live footage; (4) no evidence of psychological harm in callers or staff/dispatchers. Observational sub-studies included (i) an inner-city EMS who routinely use video livestreaming to explore acceptability in a diverse population; and (ii) staff wellbeing in an EMS not using video livestreaming for comparison to the trial site.
RESULTS: Sixty-two shifts were randomised, including 240 incidents (132 control; 108 intervention). Livestreaming was successful in 53 incidents in the intervention arm. Patient recruitment (to determine appropriateness of dispatch), and caller recruitment (to measure potential harm) were low (58/269, 22% of patients; 4/244, 2% of callers). Two progression criteria were met: (1) 86% of callers with smartphones agreed and were able to activate livestreaming; (2) 85% of requests to activate livestreaming resulted in footage being obtained; and two were indeterminate due to insufficient data: (3) 2/6 (33%) HEMS stand down due to livestreaming; (4) no evidence of psychological harm from survey, observations or interviews, but insufficient survey data from callers or comparison EMS site to be confident. Language barriers and older age were reported in interviews as potential challenges to video livestreaming by dispatchers in the inner-city EMS.
CONCLUSIONS: Progression to a definitive RCT is supported by these findings. Bystander video livestreaming from scene is feasible to implement, acceptable to both 999 callers and dispatchers, and may aid dispatch decision-making. Further assessment of unintended consequences, benefits and harm is required.
BACKGROUND: ISRCTN 11449333 (22 March 2022). https://www.isrctn.com/ISRCTN11449333.