Prehospital Trauma Care

Prehospital trauma evaluation begins with the primary assessment of airway, breathing, circulation, disability, and exposure. This is closely followed by vital signs and a secondary assessment. Key prehospital interventions include management and resuscitation according to the aforementioned principles with a focus on major hemorrhage control, airway compromise, and invasive management of tension pneumothorax. Determining the appropriate time and method for transportation (eg, ground ambulance, helicopter, police, private vehicle) to the hospital or when to terminate resuscitation are also important decisions to be made by emergency medical services clinicians.

Ascending with ultrasound: telementored eFAST in flight-a feasibility study

PURPOSE

Teleultrasound uses telecommunication technologies to transmit ultrasound images from a remote location to an expert who guides the acquisition of images and interprets them in real time. Multiple studies have demonstrated the feasibility of teleultrasound. However, its application during helicopter flight using long-term evolution (LTE) for streaming has not been studied. Therefore, we conducted a study to examine the feasibility of teleultrasound in an Airbus H145 helicopter.

METHODS

Four anesthesiologists and one military physician were recruited to perform telementored extended Focused Assessment with Sonography in Trauma (eFAST) during nine helicopter flights, each with a unique healthy volunteer. A radiologist was recruited as a remote expert, guiding the physicians in their examinations. The examining physicians reported the user experience of telementored eFAST on a questionnaire, while the remote expert rated the diagnostic quality of the images on a 1-5 Likert scale. In addition, we measured the duration of the examinations and key LTE network parameters including signal strength, quality, and continuity.

RESULTS

The images were rated to an average of 4.9 by the remote expert, corresponding to good diagnostic quality. The average duration of telementored eFAST was 05:54 min. LTE coverage was negatively affected by proximity to urban areas and ceased above 2000 ft altitude. Occasional audio problems were addressed by using the Voice over LTE network for communication. The examining physicians unanimously reported on the questionnaire that they would use telementored eFAST on patients.

CONCLUSION

Telementored eFAST is feasible in ambulance helicopters and can produce images of good diagnostic quality. However, it relies on stable LTE coverage, which is influenced by many factors, including the helicopter's altitude and flight path. Furthermore, its benefit on patient outcomes remains to be proven.

Conceptual design and optimization of a sustainable and environmentally friendly archetypal helicopter within the selection criteria and limitations

The design and mission requirements of aero vehicles, which vary on a day-to-day basis, have become major study concerns in the burgeoning aviation sector. In addition to the design and mission criteria that must be met in an aero vehicle design, the designers' primary goals are to construct original, innovative, environmentally friendly, fuel-efficient, and sustainable designs. In this study, a detailed conceptual design of a helicopter that does not need a notable runway for operation and is limited by mission and design requirements is offered. Within the scope of this research, a competitor analysis study was undertaken in accordance with the defined criteria, and design approaches were chosen based on the outcomes of competitor analysis. In addition, this research, which looks for an environmentally friendly and sustainable design, was developed with the aviation industry's demands in mind by analyzing the International Helicopter Safety Team's (IHST) data. As a result of the reports analyzed and considering the causes and consequences of accidents that have happened, the objective of the design research was to achieve a sustainable, ecologically friendly, and fuel-efficient design by reducing the number of accidents and damage. The planning and design processes as a result of this examination are essential as a step towards the helicopter being an original design and in the context of solution methodologies. This archetypal design aims to shed light on helicopter design studies and serve as a roadmap for future research.

Fatal injuries due to direct helicopter propeller strike

During a helicopter exercise, due to the scarce visibility caused by the presence of snow, a collision between a landing helicopter and one already on the ground occurred. The 40-year-old pilot of the already landed aircraft was killed as a result of a direct propeller impact in the right side of the pilot's cockpit, while the co-pilot remained uninjured. At autopsy, the macroscopic characteristic findings in the form of cut injuries and amputations along the axis of the rotor blade impact as well as a 3D reconstruction through CT-Scan were analyzed and discussed for a thorough reconstruction of the injuries and the dynamics.

Resource utilisation for patients brought to a major trauma centre by helicopter

BACKGROUND

Helicopter Emergency Medical Services (HEMS) allow critical care personnel to attend incidents alongside transporting patients to hospital. The study site is a UK based emergency department and major trauma centre, accepting flights from a wide geographical area.

AIMS

To characterise the impact of HEMS on a major trauma centre clinical resources and the impact of the UK regional trauma network launch on HEMS asset provision.

METHODS

Flight case-mix data were obtained from Emergency Department (ED) records (non-trauma patients) and from the Trauma Audit and Research Network database (trauma patients). Statistical analysis was in Excel.

RESULTS

432 flights landed at the site between August 2018 and July 2019. 178 flights originated from the incident scene (145 trauma, 26 non-trauma), 107 from other hospitals, and 5 to other hospitals. Hospitalisation was reduced to a median of 6 days.

CONCLUSIONS

Primary HEMS trauma patients utilised significant clinical resources but had shorter hospitalisations than those without HEMS intervention. The regional trauma network improved HEMS tasking and utilised critical car cars to provide advanced pre-hospital care locally. Further work should compare HEMS versus ground ambulance to determine the impact of HEMS on patient outcomes and cost implications to both HEMS operators and receiving hospital.

Prehospital coagulation measurement by a portable blood analyzer in a helicopter emergency medical service (HEMS)

In helicopter emergency medical services, HEMS, coagulopathy presents both in trauma (e.g. consumption of coagulation factors) and non-trauma cases (e.g. anticoagulant use). Therefore, in HEMS coagulation measurements appear promising and Prothrombin Time (PT) and derived INR are attractive variables herein. We tested the feasibility of prehospital PT/INR coagulation measurements in HEMS. This study was performed at the Dutch HEMS, using a portable blood analyzer (i-Stat®1, Abbott). PT/INR measurements were performed on (hemodiluted) author's blood, and both trauma- and non-trauma HEMS patients. Device-related benefits of the i-Stat PT/INR system were portability, speed and ease of handling. Limitations included a rather narrow operational temperature range (16-30 °C). PT/INR measurements (n = 15) were performed on hemodiluted blood, and both trauma and non-trauma patients. The PT/INR results confirmed effects of hemodilution and anticoagulation, however, most measurement results were in the normal INR-range (0.9-1.2). We conclude that prehospital PT/INR measurements, although with limitations, are feasible in HEMS operations.

The "Flying Intervention Team": A Novel Stroke Care Concept for Rural Areas

BACKGROUND

Endovascular treatment of large vessel occlusion in acute ischemic stroke patients is difficult to establish in remote areas, and time dependency of treatment effect increases the urge to develop health care concepts for this population.

SUMMARY

Current strategies include direct transportation of patients to a comprehensive stroke center (CSC) ("mothership model") or transportation to the nearest primary stroke center (PSC) and secondary transfer to the CSC ("drip-and-ship model"). Both have disadvantages. We propose the model "flying intervention team." Patients will be transported to the nearest PSC; if telemedically identified as eligible for thrombectomy, an intervention team will be acutely transported via helicopter to the PSC and endovascular treatment will be performed on site. Patients stay at the PSC for further stroke unit care. This model was implemented at a telestroke network in Germany. Fifteen remote hospitals participated in the project, covering 14,000 km2 and a population of 2 million. All have well established telemedically supported stroke units, an angiography suite, and a helicopter pad. Processes were defined individually for each hospital and training sessions were implemented for all stroke teams. An exclusive project helicopter was installed to be available from 8 a.m. to 10 p.m. during 26 weeks per year. Key Messages: The model of the flying intervention team is likely to reduce time delays since processes will be performed in parallel, rather than consecutively, and since it is quicker to move a medical team rather than a patient. This project is currently under evaluation (clinicaltrials NCT04270513).

Pediatric interfacility transport effects on mortality and length of stay

BACKGROUND

We aimed to evaluate the effects of interfacility pediatric critical care transport response time, physician presence during transport, and mode of transport on mortality and length of stay (LOS) among pediatric patients. We hypothesized that a shorter response time and helicopter transports, but not physician presence, are associated with lower mortality and a shorter LOS.

METHODS

Retrospective, single-center, cohort study of 841 patients (< 19 years) transported to a quaternary pediatric intensive care unit and cardiovascular intensive care unit between 2014 and 2018 utilizing patient charts and transport records. Multivariate linear and logistic regression analyses adjusted for age, diagnosis, mode of transport, response time, stabilization time, return duration, mortality risk (pediatric index of mortality-2 and pediatric risk of mortality-3), and inotrope, vasopressor, or mechanical ventilation presence on admission.

RESULTS

Four hundred and twenty-eight (50.9%) patients were transported by helicopter, and 413 (49.1%) were transported by ambulance. Physicians accompanied 239 (28.4%) transports. The median response time was 2.0 (interquartile range 1.4-2.9) hours. Although physician presence increased the median response time by 0.26 hours (P = 0.020), neither physician presence nor response time significantly affected mortality, ICU length of stay (ILOS) or hospital length of stay (HLOS). Helicopter transports were not significantly associated with mortality or ILOS, but were associated with a longer HLOS (3.24 days, 95% confidence interval 0.59-5.90) than ambulance transports (P = 0.017).

CONCLUSIONS

These results suggest response time and physician presence do not significantly affect mortality or LOS. This may reflect the quality of pre-transport care and medical control communication. Helicopter transports were only associated with a longer HLOS. Our analysis provides a framework for examining transport workforce needs and associated costs.

Characterization of fatal injuries in oil and gas industry-related helicopter accidents in the Gulf of Mexico, 2004-2014

Background

Transportation events are the most common cause of offshore fatalities in the oil and gas industry, of which helicopter accidents comprise the majority. Little is known about injury distributions in civilian helicopter crashes, and knowledge of injury distributions could focus research and recommendations for enhanced injury prevention and post-crash survival. This study describes the distribution of injuries among fatalities in Gulf of Mexico oil and gas industry-related helicopter accidents, provides a detailed injury classification to identify potential areas of enhanced safety design, and describes relevant safety features for mitigation of common injuries.

Methods

Decedents of accidents during 2004–2014 were identified, and autopsy reports were requested from responsible jurisdictions. Documented injuries were coded using the Abbreviated Injury Scale (AIS), and frequency and proportion of injuries by AIS body region and severity were calculated. Injuries were categorized into detailed body regions to target areas for prevention.

Results

A total of 35 autopsies were coded, with 568 injuries documented. Of these, 23.4% were lower extremity, 22.0% were thorax, 13.6% were upper extremity, and 13.4% were face injuries. Minor injuries were most prevalent in the face, neck, upper and lower extremities, and abdomen. Serious or worse injuries were most prevalent in the thorax (53.6%), spine (50.0%), head (41.7%), and external/other regions (75.0%). The most frequent injuries by detailed body regions were thoracic organ (23.0%), thoracic skeletal (13.3%), abdominal organ (9.6%), and leg injuries (7.4%). Drowning occurred in 13 (37.1%) of victims, and drowning victims had a higher proportion of moderate brain injuries (7.8%) and lower number of documented injuries (3.8) compared with non-drowning victims (2.9 and 9.4%, respectively).

Conclusions

Knowledge of injury distributions focuses and prioritizes the need for additional safety features not routinely used in helicopters. The most frequent injuries occurred in the thorax and lower extremity regions. Future research requires improved and expanded data, including collection of detailed data to allow characterization of both injury mechanism and distribution. Improved safety systems including airbags and helmets should be implemented and evaluated for their impact on injuries and fatalities.

Output-constrained fixed-time control for autonomous ship landing of helicopters

In this paper, we consider a fixed-time autonomous ship landing control design for helicopters subject to asymmetric output constraints, model uncertainties and external perturbations. By incorporating a universal barrier function into the backstepping design, an output-constrained fixed-time control algorithm is proposed, where a new adaptive estimation method is introduced to compensate the effects resulting from uncertainties and disturbances. To avoid crash and overcome the limitation of the helicopter's under-actuated property, the whole landing operation is completed in a dual-phase landing sequence with two controllers, which are both designed based on the output-constrained fixed-time control algorithm. The proposed control strategy guarantees that the tracking and landing errors converge into a small neighborhood of zero in a fixed settling time without violating the constraint requirement. Numerical comparative simulations are executed to further verify the prominent control performance.

How Does Mission Ground Time Impact on Population Coverage of Aeromedical Retrieval Systems?

BACKGROUND

Aeromedical retrieval is an essential component of contemporary emergency care systems. However, in many locations, ground emergency medical services are dispatched to the scene of an incident first to assess the patient and then call for a helicopter if needed. The time to definitive care therefore includes the helicopter's flight to the scene, flight to the trauma center, and nonflying time. Mission ground time (MGT) includes the time required to get the helicopter airborne, as well as time spent at the scene, packaging and loading the casualty into the aircraft. Estimates of MGT typically vary from 10 to 30 min. The impact of MGT duration on population coverage-the number of residents that could be taken to a trauma center within a set time-is not known. The aim of this study was to compare population coverage for different durations of MGT in a single state.

METHODS

Coverage was calculated using elliptical coverage areas ("isochrones") based on the location of helicopter bases and Level I and Level II trauma centers. The calculations were performed using Microsoft Excel, assuming a cruising speed of 133 knots (246 km/h), and mapped using arcGIS. The access time threshold was set at 60 min, and we evaluated MGTs of 10, 15, 20, 25, and 30 min.

RESULTS

MGT has a marked impact on population coverage. The effect is, furthermore, not linear. When considering the state's three Level I trauma centers, decreasing MGT from 30 to 10 min increased population coverage from 61.2% to 84.2%. When also considering Level II centers, decreasing MGT from 30 min to 10 min increased coverage by 20%.

CONCLUSIONS

Elliptical isochrones, with allowance for MGT, provide realistic estimates of population coverage. MGT significantly impacts the proportion of the population that can be taken to a Level I and/or Level II Trauma Center within a set time. The impact is not linear, reflecting the uneven distribution of the population. Consideration should be given to minimizing MGT to preserve the benefits of aeromedical retrieval.

Pre-hospital care & interfacility transport of 385 COVID-19 emergency patients: an air ambulance perspective

Background

COVID-19, the pandemic caused by the severe acute respiratory syndrome coronavirus-2, is challenging healthcare systems worldwide. Little is known about problems faced by emergency medical services—particularly helicopter services—caring for suspected or confirmed COVID-19 patients. We aimed to describe the issues faced by air ambulance services in Europe as they transport potential COVID-19 patients.

Methods

Nine different HEMS providers in seven different countries across Europe were invited to share their experiences and to report their data regarding the care, transport, and safety measures in suspected or confirmed COVID-19 missions. Six air ambulance providers in six countries agreed and reported their data regarding development of special procedures and safety instructions in preparation for the COVID-19 pandemic. Four providers agreed to provide mission related data. Three hundred eighty-five COVID-19-related missions were analysed, including 119 primary transport missions and 266 interfacility transport missions.

Results

All providers had developed special procedures and safety instructions in preparation for COVID-19. Ground transport was the preferred mode of transport in primary missions, whereas air transport was preferred for interfacility transport. In some countries the transport of COVID-19 patients by regular air ambulance services was avoided. Patients in interfacility transport missions had a significantly higher median (range) NACA Score 4 (2-5) compared with 3 (1-7), needed significantly more medical interventions, were significantly younger (59.6 ± 16 vs 65 ± 21 years), and were significantly more often male (73% vs 60.5%).

Conclusions

All participating air ambulance providers were prepared for COVID-19. Safe care and transport of suspected or confirmed COVID-19 patients is achievable. Most patients on primary missions were transported by ground. These patients were less sick than interfacility transport patients, for whom air transport was the preferred method.

A comparison of physician-staffed helicopters and ground ambulances transport for the outcome of severe thoracic trauma patients

PURPOSE

We retrospectively investigated prognostic factors for severe thoracic trauma patients evacuated by a physician-staffed helicopter emergency medical service (HEMS) and ground ambulance using the Japan Trauma Data Bank (JTDB).

METHODS

This study was a retrospective analysis of the JTDB database. The study period was from January 2004 to May 2019. The subjects were divided into two groups, according to the type of transportation: the Heli group included cases transported by the HEMS, while the Ambulance group included cases transported by ground ambulance.

RESULTS

During the investigation period, a total of 57,872 patients were enrolled as subjects, including 7238 in the Heli group and 50,634 in the Ambulance group. The average age, male ratio, average injury severity score (ISS), average revised trauma score (RTS) and survival ratio were significantly greater in the Heli group than in the Ambulance group. After performing a propensity score-matched analysis, there were no statistical differences concerning the age, sex, ISS, RTS between the two groups. However, the survival ratio in the Heli group remained greater than that in the Ambulance group. When variables that showed statistical significance in the univariate analysis were included in a multivariate analysis, the RTS, transport by the HEMS, age, ISS and female gender were identified as significant predictors of a survival outcome. The HEMS was significantly associated with an increased survival ratio (odds ratio: 1.69; 95% confidence interval: 1.51-1.88) compared with a ground ambulance.

CONCLUSION

The present study showed that transport by the HEMS improved the survival rate compared to that by a ground ambulance for patients with severe thoracic trauma.

Association of helicopter transportation and improved mortality for patients with major trauma in the northern French Alps trauma system: an observational study based on the TRENAU registry

BACKGROUND

Prompt prehospital triage and transportation are essential in an organised trauma system. The benefits of helicopter transportation on mortality in a physician-staffed pre-hospital trauma system remains unknown. The aim of the study was to assess the impact of helicopter transportation on mortality and prehospital triage.

METHODS

Data collection was based on trauma registry for all consecutive major trauma patients transported by helicopter or ground ambulance in the Northern French Alps Trauma system between 2009 and 2017. The primary endpoint was in-hospital death. We performed multivariate logistic regression to compare death between helicopter and ground ambulance.

RESULTS

Overall, 9458 major trauma patients were included. 37% (n = 3524) were transported by helicopter, and 56% (n = 5253) by ground ambulance. Prehospital time from the first call to the arrival at hospital was longer in the helicopter group compared to the ground ambulance group, respectively median time 95 [72-124] minutes and 85 [63-113] minutes (P < 0.001). Median transport time was similar between groups, 20 min [13-30] for helicopter and 21 min [14-32] for ground ambulance. Using multivariate logistic regression, helicopter was associated with reduced mortality compared to ground ambulance (adjusted OR 0.70; 95% CI, 0.53-0.92; P = 0.01) and with reduced undertriage (OR 0.69 95% CI, 0.60-0.80; P < 0.001).

CONCLUSION

Helicopter was associated with reduced in-hospital death and undertriage by one third. It did not decrease prehospital and transport times in a system with the same crew using both helicopter or ground ambulance. The mortality and undertriage benefits observed suggest that the helicopter is the proper mode for long-distant transport to a regional trauma centre.

Analysis of emergency air medical services over 9 years in the Penghu archipelago of Taiwan

Objective:

Emergency air medical services (EAMS) share a common helicopter system for prehospital care and transfer in several countries. In Penghu, two systems are involved in EAMS: the helicopter and C130 systems. Given their features and limitations, patients using the two systems have significantly different characteristics.

Materials and Methods:

To clearly understand the disease patterns and dynamic changes in transferred patients, we studied 1228 patients transported from Penghu to Taiwan between January 2009 and December 2017.

Results:

Our findings show that the helicopter group had more acute diseases, while the C130 system group had more chronic diseases. Cardiovascular disease was the most common diagnosis (328 patients, 26.71%), followed by cerebrovascular disease (263 patients, 21.41%) and gastrointestinal disease (221 patients, 17.99%). Following interventions to support local medicine by Tri-Service General Hospital and the establishment of a cardiac catheterization laboratory, the annual number of transported patients decreased, especially those with cardiovascular diseases. The disease pattern also shifted from acute to chronic disease.

Conclusion:

Current data indicate that the local medical system is developing the ability to manage chronic diseases and care problems. This article analyzes dynamic changes in the disease patterns of transferred patients in both EAMS groups, providing a strong foundation for developing local medical systems.

Comparison of the drift potential of two application methods for the control of oak processionary moths with biocidal products in an oak avenue

The control of oak processionary moths (OPM; Thaumetopoea processionea) with biocidal products has become more important to protect humans from its urticating hairs. Two important application methods are cannon sprayers and helicopters. However, drift of insecticides to non-target areas might occur during the treatment resulting in potential risks for non-target organisms. Until now, information about the direct drift resulting from the applications are missing because equipment for the application of biocidal products is not tested or regulated within Europe. The aim of this work is to measure the direct drift in up to 100 m distance resulting from the application of biocidal products using a cannon sprayer and helicopter in an oak avenue. Furthermore, two different nozzles were tested for the helicopter application. The results show high drift potential with decreasing concentrations in relation to the distance to the treated area. Considering the 50th percentile of the results, the cannon sprayer produced generally more drift than the helicopter. Considering the 90th percentile at near distance, the helicopter equipped with ID-120-05 POM nozzles showed a significantly lower drift than both other tested techniques, the helicopter equipped with the Airmix 110 05 nozzles and the cannon sprayer. Hundred m away from the treated area, both nozzles installed at the helicopter showed a lower drift than the cannon sprayer. For the first time, this study shows the drift potential of applications of biocidal products and shows the possibilities to reduce drift into non-target areas by choosing appropriate equipment. This leads to a reduction of risks for non-target organisms in the vicinity of treated avenues.

Aeromedical retrieval of trauma patients: Impact of flight path model on estimates of population coverage

BACKGROUND

The aim of this study was to compare the impact of different flight path models on the calculated population coverage of aeromedical retrieval systems, using the state of Alabama as a case study.

METHODS

Geospatial analysis of U.S. Census Bureau population data using helicopter bases and trauma centers as foci of either circular or elliptical coverage areas.

RESULTS

Circular isochrone models around helicopter bases or trauma centers suggest that the entire population of Alabama could reach a level I or II trauma center within 60 min. Elliptical isochrones, incorporating outbound and inbound flights, suggest that only 78.8% of the population have ready access to level I or II trauma centers.

CONCLUSION

While all three flight path models described have some validity and utility, simplistic circular flight time isochrones around trauma centers and helicopter bases provide overly optimistic estimates of population coverage. The elliptical model provides a more realistic evaluation.

Speech Recognition of Cochlear Implant Users Inside a Noisy Helicopter Environment

In this study, we tested whether the speech recognition, through radio communications, of cochlear implant (CI) users inside a noisy helicopter cockpit is adequate for safe flight.

METHOD

Speech recognition tests (sentences, numbers and disyllables) through a very-high-frequency radio were administered to 12 CI users in a soundproof booth, inside a helicopter with the engine turned off and turned on.

RESULTS

In quiet environments, radio communications were impacted only for disyllable intelligibility, but in noisy situations, all tests were affected.

CONCLUSIONS

CI subjects did not achieve the auditory levels recommended by the International Civil Aviation Organization.

Training and assessment of non-technical skills in Norwegian helicopter emergency services: a cross-sectional and longitudinal study

Background

Deficient non-technical skills (NTS) among providers of critical care in helicopter emergency medical services (HEMS) is a threat to patient and operational safety. Skills can be improved through simulation-based training and assessment. A previous study indicated that physicians underwent less frequent training compared to pilots and HEMS crew members (HCM) and that all professional groups in Norwegian HEMS received limited training in how to cope with fatigue. Since then, training initiatives and a fatigue risk management project has been initiated. Our study aimed to explore if the frequency of simulation-based training and assessment of NTS in Norwegian HEMS has changed since 2011 following these measures.

Methods

A cross-sectional web-based survey from October through December 2016, of physicians, HCM and pilots from all civilian Norwegian HEMS-bases reporting the overall extent of simulation-based training and assessment of NTS.

Results

Of 214 invited, 109 responses were eligible for analysis. The frequency of simulation-based training and assessment of NTS has increased significantly for all professional groups in Norwegian HEMS, most prominently for the physicians. For all groups, the frequency of assessment is generally lower than the frequency of training.

Conclusions

Physicians in Norwegian HEMS seem to have adjusted to the NTS training culture of the other crew member groups. This might be a consequence of improved NTS training programs. The use of behavioural marker systems systematically in HEMS should be emphasized.

Electronic supplementary material

The online version of this article (10.1186/s13049-018-0583-1) contains supplementary material, which is available to authorized users.

A comparative study on the frequency of simulation-based training and assessment of non-technical skills in the Norwegian ground ambulance services and helicopter emergency medical services

BACKGROUND

Inadequate non-technical skills (NTSs) among employees in the Norwegian prehospital emergency medical services (EMSs) are a risk for patient and operational safety. Simulation-based training and assessment is promising with respect to improving NTSs. The frequency of simulation-based training in and assessment of NTSs among crewmembers in the Norwegian helicopter emergency medical service (HEMS) has gained increased attention over recent years, whereas there has been much less focus on the Norwegian ground emergency medical service (GEMS). The aim of the study was to compare and document the frequencies of simulation-based training in and assessment of seven NTSs between the Norwegian HEMS and GEMS, conditional on workplace and occupation.

METHOD

A comparative study of the results from cross-sectional questionnaires responded to by employees in the Norwegian prehospital EMSs in 2016 regarding training in and assessment of NTSs during 2015, with a focus on the Norwegian GEMS and HEMS. Professional groups of interest are: pilots, HEMS crew members (HCMs), physicians, paramedics, emergency medical technicians (EMTs), EMT apprentices, nurses and nurses with an EMT licence.

RESULTS

The frequency of simulation-based training in and assessment of seven generic NTSs was statistically significantly greater for HEMS than for GEMS during 2015. Compared with pilots and HCMs, other health care providers in GEMS and HEMS undergo statistically significantly less frequent simulation-based training in and assessment of NTSs. Physicians working in the HEMS appear to be undergoing training and assessment more frequently than the rest of the health trust employees. The study indicates a tendency for lesser focus on the assessment of NTSs compared to simulation-based training.

CONCLUSION

HEMS has become superior to GEMS, in terms of frequency of training in and assessment of NTSs. The low frequency of training in and assessment of NTSs in GEMS suggests that there is a great potential to learn from HEMS and to strengthen the focus on NTSs. Increased frequency of assessment of NTSs in both HEMS and GEMS is called for.

Body temperature change and outcomes in patients undergoing long-distance air medical transport

BACKGROUND

Short-distance air medical transport for adult emergency patients does not significantly affect patients' body temperature and outcomes. This study aimed to examine the influence of long-distance air medical transport on patients' body temperatures and the relationship between body temperature change and mortality.

METHODS

We retrospectively enrolled consecutive patients transferred via helicopter or plane from isolated islands to an emergency medical center in Tokyo, Japan between April 2010 and December 2016. Patients' average body temperature was compared before and after air transport using a paired t-test, and corrections between body temperature change and flight duration were calculated using Pearson's correlation coefficient. Multivariable logistic regression models were then used to examine the association between body temperature change and in-hospital mortality.

RESULTS

Of 1253 patients, the median age was 72 years (interquartile range, 60-82 years) and median flight duration was 71 min (interquartile range, 54-93 min). In-hospital mortality was 8.5%, and average body temperature was significantly different before and after air transport (36.7 °C versus 36.3 °C; difference: -0.36 °C; 95% confidence interval, -0.30 to -0.42; p < 0.001). There was no correlation between body temperature change and flight duration (r = 0.025, p = 0.371). In-hospital death was significantly associated with (i) hyperthermia (>38.0 °C) or normothermia (36.0-37.9 °C) before air transport and hypothermia after air transport (odds ratio, 2.08; 95% confidence interval, 1.20-3.63; p = 0.009), and (ii) winter season (odds ratio, 2.15; 95% confidence interval, 1.08-4.27; p = 0.030).

CONCLUSION

Physicians should consider body temperature change during long-distance air transport in patients with not only hypothermia but also normothermia or hyperthermia before air transport, especially in winter.

Noise exposure during prehospital emergency physicians work on Mobile Emergency Care Units and Helicopter Emergency Medical Services

BACKGROUND

Prehospital personnel are at risk of occupational hearing loss due to high noise exposure. The aim of the study was to establish an overview of noise exposure during emergency responses in Mobile Emergency Care Units (MECU), ambulances and Helicopter Emergency Medical Services (HEMS). A second objective was to identify any occupational hearing loss amongst prehospital personnel.

METHODS

Noise exposure during work in the MECU and HEMS was measured using miniature microphones worn laterally to the auditory canals or within the earmuffs of the helmet. All recorded sounds were analysed in proportion to a known tone of 94 dB. Before and after episodes of noise exposure, the physicians underwent a hearing test indicating whether the noise had had any impact on the function of the outer sensory hair cells. This was accomplished by measuring the amplitude level shifts of the Distortion Product Otoacoustic Emissions. Furthermore, the prehospital personnels' hearing was investigated using pure-tone audiometry to reveal any occupational hearing loss. All prehospital personnel were compared to ten in-hospital controls.

RESULTS

Our results indicate high-noise exposure levels of ≥80 dB(A) during use of sirens on the MECU and during HEMS operations compared to in-hospital controls (70 dB(A)). We measured an exposure up to ≥90 dB(A) under the helmet for HEMS crew. No occupational hearing loss was identified with audiometry. A significant level shift of the Distortion Product Otoacoustic Emissions at 4 kHz for HEMS crew compared to MECU physicians was found indicating that noise affected the outer hair cell function of the inner ear, thus potentially reducing the hearing ability of the HEMS crew.

DISCUSSION

Further initiatives to prevent noise exposure should be taken, such as active noise reduction or custom-made in-ear protection with communication system for HEMS personnel. Furthermore, better insulation of MECU and ambulances is warranted.

CONCLUSION

We found that the exposure levels exceeded the recommendations described in the European Regulative for Noise, which requires further protective initiatives. Although no hearing loss was demonstrated in the personnel of the ground-based units, a reduced function of the outer sensory hair cells was found in the HEMS group following missions.

Locating helicopter emergency medical service bases to optimise population coverage versus average response time

Background

New South Wales (NSW), Australia has a network of multirole retrieval physician staffed helicopter emergency medical services (HEMS) with seven bases servicing a jurisdiction with population concentrated along the eastern seaboard. The aim of this study was to estimate optimal HEMS base locations within NSW using advanced mathematical modelling techniques.

Methods

We used high resolution census population data for NSW from 2011 which divides the state into areas containing 200–800 people. Optimal HEMS base locations were estimated using the maximal covering location problem facility location optimization model and the average response time model, exploring the number of bases needed to cover various fractions of the population for a 45 min response time threshold or minimizing the overall average response time to all persons, both in green field scenarios and conditioning on the current base structure. We also developed a hybrid mathematical model where average response time was optimised based on minimum population coverage thresholds.

Results

Seven bases could cover 98% of the population within 45mins when optimised for coverage or reach the entire population of the state within an average of 21mins if optimised for response time. Given the existing bases, adding two bases could either increase the 45 min coverage from 91% to 97% or decrease the average response time from 21mins to 19mins. Adding a single specialist prehospital rapid response HEMS to the area of greatest population concentration decreased the average state wide response time by 4mins. The optimum seven base hybrid model that was able to cover 97.75% of the population within 45mins, and all of the population in an average response time of 18 mins included the rapid response HEMS model.

Conclusions

HEMS base locations can be optimised based on either percentage of the population covered, or average response time to the entire population. We have also demonstrated a hybrid technique that optimizes response time for a given number of bases and minimum defined threshold of population coverage. Addition of specialized rapid response HEMS services to a system of multirole retrieval HEMS may reduce overall average response times by improving access in large urban areas.

Electronic supplementary material

The online version of this article (10.1186/s12873-017-0142-5) contains supplementary material, which is available to authorized users.

Factors influencing on-scene time in a rural Norwegian helicopter emergency medical service: a retrospective observational study

Background

Critically ill patients need to be immediately identified, properly managed, and rapidly transported to definitive care. Extensive prehospital times may increase mortality in selected patient groups. The on-scene time is a part of the prehospital interval that can be decreased, as transport times are determined mostly by the distance to the hospital. Identifying factors that affect on-scene time can improve training, protocols, and decision making. Our objectives were to assess on-scene time in the Helicopter Emergency Medical Service (HEMS) in our region and selected factors that may affect it in specific and severe conditions.

Methods

This retrospective cohort study evaluated on-scene time and factors that may affect it for 9757 emergency primary missions by the three HEMSs in western Norway between 2009 and 2013, using graphics and descriptive statistics.

Results

The overall median on-scene time was 10 minutes (IQR 5–16). The median on-scene time in patients with penetrating torso injuries was 5 minutes (IQR 3–10), whereas in cardiac arrest patients it was 20 minutes (IQR 13–28). Based on multivariate linear regression analysis, the severity of the patient’s condition, advanced interventions performed, mode of transport, and trauma missions increased the on-scene time. Endotracheal intubation increased the OST by almost 10 minutes. Treatment prior to HEMS arrival reduced the on-scene time in patients suffering from acute myocardial infarction.

Discussion

We found a short OST in preselected conditions compared to other studies. For the various patient subgroups, the strength of association between factors and OST varied. The time spent on-scene and its influencing factors were dependent on the patient’s condition. Our results provide a basis for efforts to improve decision making and reduce OST for selected patient groups.

Conclusions

The most important factors associated with increased on-scene time were the severity of the patient’s condition, the need for intubation or intravenous analgesic, helicopter transport, and trauma missions.

Electronic supplementary material

The online version of this article (10.1186/s13049-017-0442-5) contains supplementary material, which is available to authorized users.

Physician staffed helicopter emergency medical systems can provide advanced trauma life support in mountainous and remote areas

INTRODUCTION

In remote and mountainous areas, helicopter emergency medical systems (HEMS) are used to expedite evacuation and provide pre-hospital advanced trauma life support (ATLS) in major trauma victims. Aim of the study was to investigate feasibility of ATLS in HEMS mountain rescue missions and its influence on patient condition at hospital admission.

PATIENTS

58 major trauma victims (Injury Severity Score ≥16), evacuated by physician staffed HEMS from remote and mountainous areas in the State of Tyrol, Austria between 1.1.2011 and 31.12.2013.

RESULTS

Pre-hospital time exceeded 90min in 24 (44%) cases. 31 (53%) patients suffered critical impairment of at least one vital function (systolic blood pressure <90mmHg, GCS <10, or respiratory rate <10 or >30). 4 (6.9%) of 58 patients died prior to hospital admission. Volume resuscitation was restrictive: 18 (72%) of 25 hypotensive patients received ≤500ml fluids and blood pressure was increased >90mmHg at hospital admission in only 9 (36%) of these 25 patients. 8 (50%) of 16 brain trauma patients with a blood pressure <90mmHg remained hypotensive at hospital admission. Endotracheal intubation was accomplished without major complications in 15 (79%) of 19 patients with a Glasgow Coma Scale score <10. Rope operations were necessary in 40 (69%) of 58 cases and ATLS was started before hoist evacuation in 30 (75%) of them.

CONCLUSIONS

The frequent combination of prolonged pre-hospital times, with critical impairment of vital functions, supports the need for early ATLS in HEMS mountain rescue missions. Pre-hospital endotracheal intubation is possible with a high success and low complication rate also in a mountain rescue scenario. Pre-hospital volume resuscitation is restrictive and hypotension is reversed at hospital admission in only one third of patients. Prolonged pre-hospital hypotension remains an unresolved problem in half of all brain trauma patients and indicates the difficulties to increase blood pressure to a desired level in a mountain rescue scenario. Despite technical considerations, on-site ATLS is feasible for an experienced emergency physician in the majority of rope rescue operations.

Neck and shoulder muscle activity and posture among helicopter pilots and crew-members during military helicopter flight

Neck pain among helicopter pilots and crew-members is common. This study quantified the physical workload on neck and shoulder muscles using electromyography (EMG) measures during helicopter flight. Nine standardized sorties were performed, encompassing: cruising from location A to location B (AB) and performing search and rescue (SAR). SAR was performed with Night Vision Goggles (NVG), while AB was performed with (AB+NVG) and without NVG (AB-NVG). EMG was recorded for: trapezius (TRA), upper neck extensors (UNE), and sternocleido-mastoid (SCM). Maximal voluntary contractions (MVC) were performed for normalization of EMG (MVE). Neck posture of pilots and crew-members was monitored and pain intensity of neck, shoulder, and back was recorded. Mean muscle activity for UNE was ∼10% MVE and significantly higher than TRA and SCM, and SCM was significantly lower than TRA. There was no significant difference between AB-NVG and AB+NVG. Muscle activity in the UNE was significantly higher during SAR+NVG than AB-NVG. Sortie time (%) with non-neutral neck posture for SAR+NVG and AB-NVG was: 80.4%, 74.5% (flexed), 55.5%, 47.9% (rotated), 4.5%, 3.7% (lateral flexed). Neck pain intensity increased significantly from pre- (0.7±1.3) to post-sortie (1.6±1.9) for pilots (p=0.028). If sustained, UNE activity of ∼10% MVE is high, and implies a risk for neck disorders.

Prehospital ultrasound of the abdomen and thorax changes trauma patient management: A systematic review

BACKGROUND

Ultrasound examination of trauma patients is increasingly performed in prehospital services. It is unclear if prehospital sonographic assessments change patient management: providing prehospital diagnosis and treatment, determining choice of destination hospital, or treatment at the receiving hospital.

OBJECTIVE

This review aims to assess and grade the evidence that specifically examines whether prehospital ultrasound (PHUS) of the thorax and/or abdomen changes management of the trauma patient.

METHODS

A systematic review was conducted of trauma patients who had an ultrasound of the thorax or abdomen performed in the prehospital setting. PubMed, MEDLINE, Web of Science (CINAHL, EMBASE, Cochrane Central Register of Controlled Trials) and the reference lists of included studies were searched. Methodological quality was checked and risk of bias analysis performed, a level of evidence grade was assigned, and descriptive data analysis performed.

RESULTS

992 unique citations were identified, which included eight studies that met inclusion criteria with a total of 925 patients. There are no reports of randomised controlled trials. Heterogeneity exists between the included studies which ranged from a case series to retrospective and prospective non-randomised observational studies. Three studies achieved a 2+ Scottish Intercollegiate Guidelines Networks grade for quality of evidence and the remainder demonstrated a high risk of bias. The three best studies each provided examples of prehospital ultrasound positively changing patient management.

CONCLUSION

There is moderate evidence that supports prehospital physician use of ultrasound for trauma patients. For some patients, management was changed based on the results of the PHUS. The benefit of ultrasound use in non-physician services is unclear.

Effects of long and short simulated flights on the saccadic eye movement velocity of aviators

Aircrew fatigue is a major contributor to operational errors in civil and military aviation. Objective detection of pilot fatigue is thus critical to prevent aviation catastrophes. Previous work has linked fatigue to changes in oculomotor dynamics, but few studies have studied this relationship in critical safety environments. Here we measured the eye movements of US Marine Corps combat helicopter pilots before and after simulated flight missions of different durations.We found a decrease in saccadic velocities after long simulated flights compared to short simulated flights. These results suggest that saccadic velocity could serve as a biomarker of aviator fatigue.

Helicopter overtriage in pediatric trauma

BACKGROUND

Helicopter Emergency Medical Services (HEMS) have been designed to provide faster access to trauma center care in cases of life-threatening injury. However, the ideal recipient population is not fully characterized, and indications for helicopter transport in pediatric trauma vary dramatically by county, state, and region. Overtriage, or unnecessary utilization, can lead to additional patient risk and expense. In this study we perform a nationwide descriptive analysis of HEMS for pediatric trauma and assess the incidence of overtriage in this group.

METHODS

We reviewed records from the American College of Surgeons National Trauma Data Bank (2008-11) and included patients less than 16 years of age who were transferred from the scene of injury to a trauma center via HEMS. Overtriage was defined as patients meeting all of the following criteria: Glasgow Coma Scale (GCS) equal to 15, absence of hypotension, an Injury Severity Score (ISS) less than 9, no need for procedure or critical care, and a hospital length of stay of less than 24 hours.

RESULTS

A total of 19,725 patients were identified with a mean age of 10.5 years. The majority of injuries were blunt (95.6%) and resulted from motor vehicle crashes (48%) and falls (15%). HEMS transported patients were predominately normotensive (96%), had a GCS of 15 (67%), and presented with minor injuries (ISS<9, 41%). Overall, 28 % of patients stayed in the hospital for less than 24 hours, and the incidence of overtriage was 17%.

CONCLUSIONS

Helicopter overtriage is prevalent among pediatric trauma patients nationwide. The ideal model to predict need for HEMS must consider clinical outcomes in the context of judicious resource utilization. The development of guidelines for HEMS use in pediatric trauma could potentially limit unnecessary transfers while still identifying children who require trauma center care in a timely fashion.

20 years of trauma documentation in Germany--actual trends and developments

INTRODUCTION

The TraumaRegister DGU(®) has been founded 20 years ago. Although initially supported by larger hospitals and universities, it has recently become a representative registry for the care of severely injured patients in Germany. Based on the registry data some important trends and developments of the recent decades are presented.

PATIENTS AND METHODS

German trauma patients with an Injury Severity Score (ISS)≥ 16 were eligible if primary admitted from the scene. All cases documented between 1993 and 2012 (20 years) were eligible. For selected variables, an average change per years was calculated using linear regression analysis.

RESULTS

A total of 49,801 patients was analysed. The mean age was 46.3 years, and 72% were males. The following relevant trends could be observed: The average age increased dramatically from 38 to 50 years. Pre-hospital intubation rate was halfed in patients with Glasgow Coma Scale (GCS)>8 but remained constant in unconscious patients (GCS ≤ 8; 90% intubation rate). Pre-hospital volume administration decreased as well, which led to less blood transfusions (from 45% to 16%). The use of helicopters for transportation into a trauma centre decreased as well but today still 27% of all cases are transported by air. Whole-body CT was performed in about 80% of patients; this value is stable in the last four years. Hospital mortality could be reduced and was 2-3% lower than expected in recent years. The Revised Injury Severity Classification (RISC) score used as a reference here was based on TR-DGU data from the 1990s.

CONCLUSION

Standardised prospective registration of severely injured patients over 20years allows to empirically monitor trends and developments in acute trauma care.

Ten years of helicopter emergency medical services in Germany: do we still need the helicopter rescue in multiple traumatised patients?

BACKGROUND

Helicopter emergency medical service (HEMS) has been established in the preclinical treatment of multiple traumatised patients despite an ongoing controversy towards the potential benefit. Celebrating the 20th anniversary of TraumaRegister DGU(®) of the German Trauma Society (DGU) the presented study intended to provide an overview of HEMS rescue in Germany over the last 10 years analysing the potential beneficial impact of a nationwide helicopter rescue in multiple traumatised patients.

PATIENTS AND METHODS

We analysed TraumaRegister DGU(®) including multiple traumatised patients (ISS ≥ 16) between 2002 and 2012. In-hospital mortality was defined as main outcome. An adjusted, multivariate regression with 13 confounders was performed to evaluate the potential survival benefit.

RESULTS

42,788 patients were included in the present study. 14,275 (33.4%) patients were rescued by HEMS and 28,513 (66.6%) by GEMS. Overall, 66.8% (n=28,569) patients were transported to a level I trauma centre and 28.2% (n=12,052) to a level II trauma centre. Patients rescued by HEMS sustained a higher injury severity compared to GEMS (ISS HEMS: 29.5 ± 12.6 vs.

ISS GEMS

27.5 ± 11.8). Helicopter rescue teams performed more on-scene interventions, and mission times were increased in HEMS rescue (HEMS: 77.2 ± 28.7 min. vs. GEMS: 60.9 ± 26.9 min.). Linear regression analysis revealed that the frequency of HEMS rescue has decreased significantly between 2002 and 2012. In case of transportation to level I trauma centres a decrease of 1.7% per year was noted (p<0.001) while a decline of 1.6% per year (p<0.001) was measured for level II trauma centre admissions. According to multivariate logistic regression HEMS was proven a positive independent survival predictor between 2002 and 2012 (OR 0.863; 95%-CI 0.800-0.930; Nagelkerkes-R(2) 0.539) with only little differences between each year.

CONCLUSIONS

This study was able to prove an independent survival benefit of HEMS in multiple traumatised patients during the last 10 years. Despite this fact, a constant decline of HEMS rescue missions was found in multiple trauma patients due to unknown reasons. We concluded that HEMS should be used more often in case of trauma in order to guarantee the proven benefit for multiple traumatised patients.

Helicopter emergency medical service in fars province: the referral trauma center of South of iran

BACKGROUND

Considering the limited available resources, high cost of the helicopter emergency medical service (HEMS), and high load of trauma patients especially in our centers, a careful assessment of HEMS in our center seemed to be necessary for trauma patients.

METHODS

From April 2001 to September 2007, the data of all patients transferred by HEMS were extracted including: Annual number of services, clinical category, number of proper or improper services, and rescue time for HEMS and ground ambulance. The criteria for the properly transferred group included: Death or being operated in the first 24 hours of admission, admission in ICU care units, and transfer of more than three patients in one mission. Others were considered as improper group.

RESULTS

In this period through 185 flights, 225 victims were transferred. The most common reason of HEMS dispatching was trauma. The most difference of rescue time between ground ambulance and HEMS was recorded in Lamerd that was transferring patients with HEMS needed 3 hours less than ground ambulance. However, in Sarvestan, Dashte-Arjan, and Marvdasht, transferred patients with ground ambulance needed less time than air transfer. Most of transferred patients were from Kazeroon, Nourabad and Lamerd respectively while 46.3% of patients were in the proper group, and the rest were considered as improper group.

CONCLUSION

Our study revealed that helicopter dispatch to the cities like Lamerd, Lar, Khonj, Abadeh can be more effective, whereas, for the towns like Marvdasht, Dashte-Arjan, Sarvestan, Sepidan, Saadatshar, Tang Abolhayat use of HEMS should be limited to specific conditions. Our study showed inclusion of physicians in the decision making team increased the number of transferred cases.