A critical analysis of on-scene helicopter transport on survival in a statewide trauma system

Factors Influencing Outcomes of Trauma Patients Transferred in Trauma Systems by Air or Ground Ambulance: A Systematic Review

OBJECTIVES

This systematic review aims to determine the effectiveness of ambulance transportation versus helicopter transportation on mortality for trauma patients.

METHODS

A systematic review of published and unpublished databases (to August 2023) was performed. Studies, reporting mortality, for people who experienced trauma and were transported to a trauma unit by ambulance or helicopter were eligible. The Newcastle-Ottawa scale was employed to evaluate study quality.

RESULTS

Of the 7,323 studies screened, 63 met the inclusion criteria. Thirty-two percent of these studies included patients with diverse injury types, while nine studies included patients across all age groups. The majority (92%) of the included data were retrospective in nature. Eighteen studies (28.57%) achieved the highest score on the Newcastle-Ottawa scale suggesting high-quality evidence. Seven studies examining 24-h mortality reported variable findings. Eighteen studies reported mortality without exact time points through adjusted analyses, 17 favored air transport. Air transport showed an advantage across all subgroups in the adjusted data, while the unadjusted data presented relatively similar outcomes between the two modes of transport.

CONCLUSIONS

This systematic review found that adjusted analyses consistently favored air transport over ground transport. Unadjusted analyses showed no significant difference between the two modes of transport, except in specific subgroups. Further subgroup analyses revealed notable disparities between the two modalities, suggesting that these differences may be influenced by multiple factors. These findings highlight the need for further research to clarify the true impact of transport modality on trauma outcomes.

Effectiveness of road safety interventions: An evidence and gap map

Background

Road Traffic injuries (RTI) are among the top ten leading causes of death in the world resulting in 1.35 million deaths every year, about 93% of which occur in low- and middle-income countries (LMICs). Despite several global resolutions to reduce traffic injuries, they have continued to grow in many countries. Many high-income countries have successfully reduced RTI by using a public health approach and implementing evidence-based interventions. As many LMICs develop their highway infrastructure, adopting a similar scientific approach towards road safety is crucial. The evidence also needs to be evaluated to assess external validity because measures that have worked in high-income countries may not translate equally well to other contexts. An evidence gap map for RTI is the first step towards understanding what evidence is available, from where, and the key gaps in knowledge.

Objectives

The objective of this evidence gap map (EGM) is to identify existing evidence from all effectiveness studies and systematic reviews related to road safety interventions. In addition, the EGM identifies gaps in evidence where new primary studies and systematic reviews could add value. This will help direct future research and discussions based on systematic evidence towards the approaches and interventions which are most effective in the road safety sector. This could enable the generation of evidence for informing policy at global, regional or national levels.

Search Methods

The EGM includes systematic reviews and impact evaluations assessing the effect of interventions for RTI reported in academic databases, organization websites, and grey literature sources. The studies were searched up to December 2019.

Selection Criteria

The interventions were divided into five broad categories: (a) human factors (e.g., enforcement or road user education), (b) road design, infrastructure and traffic control, (c) legal and institutional framework, (d) post-crash pre-hospital care, and (e) vehicle factors (except car design for occupant protection) and protective devices. Included studies reported two primary outcomes: fatal crashes and non-fatal injury crashes; and four intermediate outcomes: change in use of seat belts, change in use of helmets, change in speed, and change in alcohol/drug use. Studies were excluded if they did not report injury or fatality as one of the outcomes.

Data Collection and Analysis

The EGM is presented in the form of a matrix with two primary dimensions: interventions (rows) and outcomes (columns). Additional dimensions are country income groups, region, quality level for systematic reviews, type of study design used (e.g., case-control), type of road user studied (e.g., pedestrian, cyclists), age groups, and road type. The EGM is available online where the matrix of interventions and outcomes can be filtered by one or more dimensions. The webpage includes a bibliography of the selected studies and titles and abstracts available for preview. Quality appraisal for systematic reviews was conducted using a critical appraisal tool for systematic reviews, AMSTAR 2.

Main Results

The EGM identified 1859 studies of which 322 were systematic reviews, 7 were protocol studies and 1530 were impact evaluations. Some studies included more than one intervention, outcome, study method, or study region. The studies were distributed among intervention categories as: human factors (n = 771), road design, infrastructure and traffic control (n = 661), legal and institutional framework (n = 424), post-crash pre-hospital care (n = 118) and vehicle factors and protective devices (n = 111). Fatal crashes as outcomes were reported in 1414 records and non-fatal injury crashes in 1252 records. Among the four intermediate outcomes, speed was most commonly reported (n = 298) followed by alcohol (n = 206), use of seatbelts (n = 167), and use of helmets (n = 66). Ninety-six percent of the studies were reported from high-income countries (HIC), 4.5% from upper-middle-income countries, and only 1.4% from lower-middle and low-income countries. There were 25 systematic reviews of high quality, 4 of moderate quality, and 293 of low quality.

Authors' Conclusions

The EGM shows that the distribution of available road safety evidence is skewed across the world. A vast majority of the literature is from HICs. In contrast, only a small fraction of the literature reports on the many LMICs that are fast expanding their road infrastructure, experiencing rapid changes in traffic patterns, and witnessing growth in road injuries. This bias in literature explains why many interventions that are of high importance in the context of LMICs remain poorly studied. Besides, many interventions that have been tested only in HICs may not work equally effectively in LMICs. Another important finding was that a large majority of systematic reviews are of low quality. The scarcity of evidence on many important interventions and lack of good quality evidence-synthesis have significant implications for future road safety research and practice in LMICs. The EGM presented here will help identify priority areas for researchers, while directing practitioners and policy makers towards proven interventions.

Appropriate Air Medical Services Utilization and Recommendations for Integration of Air Medical Services Resources into the EMS System of Care: A Joint Position Statement and Resource Document of NAEMSP, ACEP, and AMPA

Air medical services involves providing medical care in transit while using either fixed wing (airplane) or rotor wing (helicopter) aircraft to move patients between locations. The modern use and availability of air medical services has expanded access to various health system resources, including specialty care. While this is generally beneficial, such expansion has also contributed to the complexity of health care delivery systems.(1, 2) Since the publication of the 2013 joint position statement Appropriate and Safe Utilization of Helicopter Emergency Medical Services,(3) research has shown that patient benefit is gained from the clinical care capabilities of air medical services independent of potential time saved when transporting patients.(4-6) Because the evidence basis for utilization of air medical services continues to evolve, NAEMSP, ACEP, and AMPA believe that an update regarding the appropriate utilization of air medical services is warranted, and that such guidance for utilization can be divided into three major categories: clinical considerations, safety considerations, and system integration and quality assurance considerations.

Identifying causes of delay in interfacility transfer of patients by air ambulance

OBJECTIVES

Population density can limit the level of care that can be provided in local facilities in Ontario, and as such, patients with severe illnesses often require interfacility transfers to access specialized care. This study aimed to identify causes of delay in interfacility transport by air ambulance in Ontario.

METHODS

Causes of delay were identified by manual review of electronic patient care records (ePCRs). All emergent interfacility transfers conducted by Ornge, the sole provider of air-based medical transport in Ontario, between January 1, 2016 and December 31, 2016 were included. The ePCRs were reviewed if they met one or more of the following: (1) contained a standardized delay code; (2) contained free text including "delay", "wait", or "duty-out"; (3) were above the 75th percentile in total transport time; or (4) were above the 90th percentile in time to bedside, time at the sending hospital, or time to receiving facility.

RESULTS

Our search strategy identified 1,220 ePCRs for manual review, which identified a total of 872 delays. Common delays cited included aircraft refueling (234 delays), waiting for land emergency medical service (EMS) escort (146), and staffing- or dispatch-related issues (124). Other delays included weather/environmental hazards (43); mechanical issues (36); and procedures, imaging, or stabilization (80).

CONCLUSIONS

Some common causes of interfacility delay are potentially modifiable: better trip planning around refueling and improved coordination with local EMS, could reduce delays experienced during interfacility trips. To better understand causes of delay, we would benefit from improved documentation and record availability which limited the results in this study.

Time-saving effects using helicopter transportation: comparison to a ground transportation time predicted using a social navigation software

Previous comparison studies regarding 2 types of transportation, helicopter (HEMS) versus ground emergency medical services (GEMS), have shown underlying heterogeneity as these options have completely different routes and consequent times with reference to one patient. To compare the 2 types of transportation on a case-by-case basis, we analyzed the retrospectively reviewed HEMS and predicted GEMS data using an open-source navigation software.Patients transferred by military HEMS from 2016 to 2019 were retrospectively enrolled. The HEMS records on the time of notification, injury point and destination address, and time required were reviewed. The GEMS data on distance and the predicted time required were acquired using open-source social navigation systems. Comparison analyses between the two types of transportation were conducted. Furthermore, linear logistic regression analyses were performed on the distance and time of the two options.A total of 183 patients were enrolled. There was no statistical difference (P = .3021) in the distance between the 2 types of transportation, and the HEMS time was significantly shorter than that of GEMS (61.31 vs 116.92 minutes, P < .001). The simple linear curves for HEMS and GEMS were separately secured, and two graphs presented the statistical significance (P) as well as reasonable goodness-of-fit (R2). In general, the HEMS graph demonstrates a more gradual slope and narrow distribution compared to that of GEMS.Ideally, HEMS is identified as a better transportation modality because it has a shorter transportation time (56 minutes saved) and a low possibility of potential time delays (larger R2). With a strict patient selection, HEMS can rescue injured or emergent patients who are "out of the golden hour."

Impact of a New Helicopter Base on Transport Time and Survival in a Rural Adult Trauma Population

BACKGROUND

Significant disparities in access to prompt helicopter transport exist among rural trauma populations. We evaluated the impact of an additional helicopter base on transport time and mortality in a rural adult trauma population.

MATERIALS AND METHODS

We performed a retrospective cohort study of adult patients with trauma transported by helicopter from scene to a level one trauma center between 2014 and 2018. A new rural helicopter base added to the trauma center's catchment area in 2016 served as the transition time for an interrupted time series analysis. Patients injured in this base's county and adjoining counties were analyzed. Baseline characteristics were compared with a Student's t-test and Pearson's chi-squared test. Cox and linear regression models evaluated the new base's effect on mortality and transport time, respectively.

RESULTS

A total of 332 patients were analyzed: 120 (36.1%) transported before the addition of the new helicopter base and 212 (63.9%) transported after. Patients transported after the addition of the base had higher injury severity score (13.7 versus 10.1, P < 0.001) and were more likely to receive blood en route (19.3% versus 6.7%, P = 0.005). After the addition of the base, there was a decreased hazard ratio for mortality (hazard ratio 0.26, 95% confidence interval: 0.11-0.65, P = 0.004) with no significant change in transport time (-36.7 min, P = 0.071) for the area.

CONCLUSIONS

Local helicopter transport units may confer improved survival for the injured patient. This study demonstrates the important role of helicopter transport within a regional trauma system and the impact that expanded access to rapid air transport can have on mortality.

Helicopter Transport Has Decreased Over Time and Transport From Scene or Hospital Matters

OBJECTIVE

Several reports have found helicopter emergency medical services (HEMS) to be associated with a lower risk of mortality compared with ground emergency medical services (GEMS); however, most studies did not control for transport time or stratify interfacility versus scene. We hypothesize that the HEMS transport rate has decreased nationally and that the risk of mortality for HEMS is similar to GEMS when adjusting for transport time and stratifying by scene or interfacility.

METHODS

The Trauma Quality Improvement Program (2010-2016) was queried for adult patients transported by HEMS or GEMS. Multivariable logistic regression was used.

RESULTS

The HEMS transport rate decreased by 38.2% from 2010 to 2016 (P < .001). After controlling for known predictors of mortality and transport time, HEMS was associated with a decreased risk of mortality compared with GEMS for adult trauma patient transports (odds ratio = 0.74; 95% confidence interval [CI], 0.71-0.77; P < .001). Compared with GEMS, HEMS transports from the scene were associated with a decreased risk of mortality (OR = 0.63; 95% CI, 0.60-0.66; P < .001), whereas HEMS interfacility transfer was associated with an increased risk of mortality (OR = 1.22; 95% CI, 1.14-1.31; P < .001).

CONCLUSION

The rate of HEMS transports in trauma has decreased by nearly 40% over the past 7 years. Our results suggest that HEMS use for scene transports is beneficial for the survival of trauma patients.

Trauma system resource preservation: A simple scene triage tool can reduce helicopter emergency medical services overutilization in a state trauma system

BACKGROUND

Helicopter emergency medical services improve survival in some injured patients but current utilization leads to significant overtriage with considerable numbers of transported patients discharged home from the emergency department or found to have non-time-sensitive injuries. Current triage models for utilization are complex and untested.

METHODS

Data from a state trauma registry were reviewed from 1987 to 1993 and from 2013 to 2015 and compared. Data from 2013 to 2015 were analyzed for field information found to influence mortality and a model for low mortality-risk patients designed.

RESULTS

Indexed to population, a major increase in numbers of injured patients transported directly to designated trauma centers (39.849-167.626/100,000/year) occurred with an increased portion transported by helicopter emergency medical services from 7.28% to 9.26%. A simple triage tool to predict low mortality rates was designed utilizing results from logistic regression. Nongeriatric adult patients (age, 16.0-69.9 years) with a blunt injury mechanism, normal Glasgow Coma Scale motor score, pulse rate of 60 bpm to 120 bpm and respiratory rate of 10 breaths per minute to 29 breaths per minute are at low risk for mortality. Cost for helicopter transportation was substantially higher than ground transportation based on available data. Cost differentials in transport mode increased patient financial risk when helicopter transportation was utilized.

CONCLUSION

Implementing a simple decision tool designating nongeriatric adult patients with a blunt injury mechanism, normal Glasgow Coma Scale motor score, systolic blood pressure greater than 90 mm Hg, pulse rate of 60 bpm to 120 bpm, and respiratory rate of 10 breaths per minute to 29 breaths per minute to ground transportation would result in substantial savings without an increase in mortality and reduce risk of patient financial harm.

LEVEL OF EVIDENCE

Prognostic/Epidemiological study, level IV. Economic and value based evaluation, level IV.

Analysis of Helicopter-Transported Trauma Patients at a Regional Trauma Center

Our medical center's regional helicopter emergency medical service (HEMS) serves southeastern North Carolina. Judicious HEMS use is vital to ensure that the resource is available for critically injured patients and to reduce morbidity and mortality by providing timely access to definitive care. We reviewed HEMS use, clinical outcomes, and overtriage rates. The data included airlifted trauma patients from January 2004 to December 2012. Of 1210 total patients, 733 were flown directly from the scene (FS) and 477 from referring hospitals (FH). The HEMS catchment area was a 100-mile radius of our trauma center. FS patients were younger and sustained more motor vehicle collisions. FH patients were older and sustained more falls. FS patients required more hospital resources including longer ventilator requirements, intensive care unit (ICU) stay, and hospital stay. For all HEMS patients, there was 92.2 per cent blunt injury, 47.5 per cent required Trauma I or II activation, 31 per cent required mechanical ventilation, and 50 per cent required ICU care. 59.5 per cent of HEMS trauma patients were critically injured (defined as requiring either immediate surgical intervention, immediate ICU admission, or immediate death). The overtriage rate was 1.8 per cent. The emergency department mortality rate was 2.3 per cent and the ultimate mortality rate was 7.5 per cent. Most of the airlifted trauma patients were critically injured, and therefore, HEMS transport was appropriate. However, overtriage was low, suggesting high incidence of undertriage. There should be a lower threshold for HEMS use for trauma patients in our region. More research is needed to determine ideal overtriage and undertriage rates.

Improved Survival for Rural Trauma Patients Transported by Helicopter to a Verified Trauma Center: A Propensity Score Analysis

OBJECTIVES

Recent studies using advanced statistical methods to control for confounders have demonstrated an association between helicopter transport (HT) versus ground ambulance transport (GT) in terms of improved survival for adult trauma patients. The aim of this study was to apply a methodologically vigorous approach to determine if HT is associated with a survival benefit for when trauma patients are transported to a verified trauma center in a rural setting.

METHODS

The ascertainment of trauma patients age ≥ 15 years (n = 469 cases) by HT and (n = 580 cases) by GT between 1999 and 2012 was restricted to the scene of injury in a rural area of 10 to 35 miles from the trauma center. The propensity score (PS) was determined using data including demographics, prehospital physiology, intubation, total prehospital time, and injury severity. The PS matching was performed with different calipers to select a higher percentage of matches of HT compared to GT patients. The outcome of interest was survival to discharge from hospital. Identical logistic regression analysis was done taking into account for each matched design to select an appropriate effect estimate and confidence interval (CI) controlling for initial vital signs in the emergency department, the need for urgent surgery, intensive care unit admission, and mechanical ventilation.

RESULTS

Unadjusted mortalities for HT compared to GT were 7.7 and 5.3%, respectively (p > 0.05). The adjusted rates were 4.0% for HT and 7.6% for GT (p < 0.05). In a PS well-matched data set, HT was associated with a 2.69-fold increase in odds of survival compared to GT patients (adjusted odds ratio = 2.69; 95% CI = 1.21-5.97).

CONCLUSIONS

In a rural setting, we demonstrated improved survival associated with HT compared to GT for scene transportation of adult trauma patients to a verified Level II trauma center using an advanced methodologic approach, which included adjustment for transport distance. The implication of survival benefit to rural population is discussed. We recommend larger studies with multiple trauma systems need to be repeated using similar study methodology to substantiate our findings.

Air Versus Ground Transportation in Isolated Severe Head Trauma: A National Trauma Data Bank Study

BACKGROUND

The effect of prehospital helicopter emergency medical services (HEMS) on mortality has been analyzed previously in polytrauma patients with discordant results.

OBJECTIVE

Our aim was to compare outcomes in patients with isolated severe blunt traumatic brain injuries (TBIs) transported by HEMS or ground emergency medical services (GEMS).

METHODS

We conducted a National Trauma Data Bank study (2007-2014). All adult patients (≥16 years old) who sustained an isolated severe blunt TBI and were transported by HEMS or GEMS were included in the study.

RESULTS

There were 145,559 patients who met the inclusion criteria. Overall, 116,391 (80%) patients were transported via GEMS and 29,168 (20%) via HEMS. Median transportation time was longer for HEMS patients (41 vs. 25 min; p < 0.001). HEMS patients were more likely to have hypotension (2.7% vs. 1.5%; p < 0.001), Glasgow Coma Scale (GCS) score < 9 (38.2% vs. 10.9%; p < 0.001), and head Abbreviation Injury Scale (AIS) score of 5 (20.1% vs. 9.7%; p < 0.001). Stepwise logistic regression analysis identified age ≥ 65 years old, male sex, hypotension, GCS score < 9, prehospital intubation, and head AIS scores 4 and 5 as independent predictors of mortality. Helicopter transportation was independently associated with improved survival (odds ratio [OR] 0.55; 95% confidence interval [CI] 0.47-0.67; p < 0.001). Admission to a Level I trauma center was an independent predictor of survival (OR 0.64; 95% CI 0.53-0.82; p = 0.001). Regardless of head AIS, helicopter transport was an independent predictor of survival (AIS 3: OR 0.35; p < 0.001; AIS 4: OR 0.44; p < 0.001; AIS 5: OR 0.76; p < 0.001). A prolonged transport time was not an independent predictor of mortality.

CONCLUSIONS

Helicopter transport, in adult patients with isolated severe TBI, is associated with improved survival.

External validation of the Air Medical Prehospital Triage score for identifying trauma patients likely to benefit from scene helicopter transport

BACKGROUND

The Air Medical Prehospital Triage (AMPT) score was developed to identify injured patients who may benefit from scene helicopter emergency medical services (HEMS) transport. External validation using a different data set is essential to ensure reliable performance. The study objective was to validate the effectiveness of the AMPT score to identify patients with a survival benefit from HEMS using the Pennsylvania Trauma Outcomes Study registry.

METHODS

Patients 16 years or older undergoing scene HEMS or ground EMS (GEMS) transport in the Pennsylvania Trauma Outcomes Study registry 2000-2013 were included. Patients with 2 or higher AMPT score points were triaged to HEMS, while those with less than 2 points were triaged to GEMS. Multilevel Poisson regression determined the association of survival with actual transport mode across AMPT score triage assignments, adjusting for demographics, mechanism, vital signs, interventions, and injury severity. Successful validation was defined as no survival benefit for actual HEMS transport in patients triaged to GEMS by the AMPT score, with a survival benefit for actual HEMS transport in patients triaged to HEMS by the AMPT score. Subgroup analyses were performed in patients treated by advanced life support providers and patients with transport times longer than 10 minutes.

RESULTS

There were 222,827 patients included. For patients triaged to GEMS by the AMPT score, actual transport mode was not associated with survival (adjusted relative risk, 1.004; 95% confidence interval, 0.999-1.009; p = 0.08). For patients triaged to HEMS by the AMPT score, actual HEMS transport was associated with a 6.7% increase in the relative probability of survival (adjusted relative risk, 1.067; 95% confidence interval, 1.040-1.083, p < 0.001). Similar results were seen in all subgroups.

CONCLUSIONS

This study is the first to externally validate the AMPT score, demonstrating the ability of this tool to reliably identify trauma patients most likely to benefit from HEMS transport. The AMPT score should be considered when protocols for HEMS scene transport are developed and reviewed.

LEVEL OF EVIDENCE

Epidemiologic/prognostic study, level III; therapeutic/care management study, level IV.

Development and Validation of the Air Medical Prehospital Triage Score for Helicopter Transport of Trauma Patients

OBJECTIVE

The aim of this study was to develop and internally validate a triage score that can identify trauma patients at the scene who would potentially benefit from helicopter emergency medical services (HEMS).

SUMMARY BACKGROUND DATA

Although survival benefits have been shown at the population level, identification of patients most likely to benefit from HEMS transport is imperative to justify the risks and cost of this intervention.

METHODS

Retrospective cohort study of subjects undergoing scene HEMS or ground emergency medical services (GEMS) in the National Trauma Databank (2007-2012). Data were split into training and validation sets. Subjects were grouped by triage criteria in the training set and regression used to determine which criteria had a survival benefit associated with HEMS. Points were assigned to these criteria to develop the Air Medical Prehospital Triage (AMPT) score. The score was applied in the validation set to determine whether subjects triaged to HEMS had a survival benefit when actually transported by helicopter.

RESULTS

There were 2,086,137 subjects included. Criteria identified for inclusion in the AMPT score included GCS <14, respiratory rate <10 or >29, flail chest, hemo/pneumothorax, paralysis, and multisystem trauma. The optimal cutoff for triage to HEMS was ≥2 points. In subjects triaged to HEMS, actual transport by HEMS was associated with an increased odds of survival (AOR 1.28; 95% confidence interval [CI] 1.21-1.36, P < 0.01). In subjects triaged to GEMS, actual transport mode was not associated with survival (AOR 1.04; 95% CI 0.97-1.11, P = 0.20).

CONCLUSIONS

The AMPT score identifies patients with improved survival following HEMS transport and should be considered in air medical triage protocols.

Factors Associated with the Use of Helicopter Inter-facility Transport of Trauma Patients to Tertiary Trauma Centers within an Organized Rural Trauma System

OBJECTIVE

A review of the literature yielded little information regarding factors associated with the decision to use ground (GEMS) or helicopter (HEMS) emergency medical services for trauma patients transferred inter-facility. Furthermore, studies evaluating the impact of inter-facility transport mode on mortality have reported mixed findings. Since HEMS transport is generally reserved for more severely injured patients, this introduces indication bias, which may explain the mixed findings. Our objective was to identify factors at referring non-tertiary trauma centers (NTC) influencing transport mode decision.

METHODS

This was a case-control study of trauma patients transferred from a Level III or IV NTC to a tertiary trauma center (TTC) within 24-hours reported to the Oklahoma State Trauma Registry between 2005 and 2012. Multivariable logistic regression was used to determine clinical and non-clinical factors associated with the decision to use HEMS.

RESULTS

A total of 7380 patients met the study eligibility. Of these, 2803(38%) were transported inter-facility by HEMS. Penetrating injury, prehospital EMS transport, severe torso injury, hypovolemic shock, and TBI were significant predictors (p<0.05) of HEMS use regardless of distance to a TTC. Association between HEMS use and male gender, Level IV NTC, and local ground EMS resources varied by distance from the TTC. Many HEMS transported patients had minor injuries and normal vital signs.

CONCLUSIONS

Our results suggest that while distance remains the most influential factor associated with HEMS use, significant differences exist in clinical and non-clinical factors between patients transported by HEMS versus GEMS. To ensure comparability of study groups, studies evaluating outcome differences between HEMS and GEMS should take factors determining transport mode into account. The findings will be used to develop propensity scores to balance baseline risk between GEMS and HEMS patients for use in subsequent studies of outcomes.

Does Mode of Transport Confer a Mortality Benefit in Trauma Patients? Characteristics and Outcomes at an Ontario Lead Trauma Hospital

Objectives

Evidence-based guidelines regarding the optimal mode of transport for trauma patients from scene to trauma centre are lacking. The purpose of this study was to investigate the relationship between trauma patient outcomes and mode of transport at a single Ontario Level I Trauma Centre, and specifically to investigate if the mode of transport confers a mortality benefit.

Methods

A historical, observational cohort study was undertaken to compare rotor-wing and ground transported patients. Captured data included demographics, injury severity, temporal and mortality variables. TRISS-L analysis was performed to examine mortality outcomes.

Results

387 rotor-wing transport and 2,759 ground transport patients were analyzed over an 18-year period. Rotor-wing patients were younger, had a higher Injury Severity Score, and had longer prehospital transport times. Mechanism of injury was similarly distributed between groups. After controlling for heterogeneity with TRISS-L analysis, the mortality of rotor-wing patients was found to be lower than predicted mortality, whereas the converse was found with ground patients.

Conclusion

Rotor-wing and ground transported trauma patients represent heterogeneous populations. Accounting for these differences, rotor-wing patients were found to outperform their predicted mortality, whereas ground patients underperformed predictions.

Impact of Helicopter Emergency Medical Service in Traumatized Patients: Which Patient Benefits Most?

INTRODUCTION

The Helicopter Emergency Medical Service (HEMS) was established for the prehospital trauma care of patients. Improved rescue times and increased coverage areas are discussed as specific advantages of HEMS. We recently found evidence that HEMS exerts beneficial effects on outcomes for severely injured patients. However, it still remains unknown which group of trauma patients might benefit most from HEMS rescue. Consequently, the unique aim of this study was to reveal which patients might benefit most from HEMS rescue.

METHODS

Trauma patients (ISS ≥9) primarily treated by HEMS or ground emergency medical services (GEMS) between 2002 and 2012 were analysed using the TraumaRegister DGU. A multivariate regression analysis was used to reveal the survival benefit between different trauma populations.

RESULTS

The study included 52 281 trauma patients. Of these, 68.8% (35 974) were rescued by GEMS and 31.2% (16 307) by HEMS. HEMS patients were more severely injured compared to GEMS patients (ISS: HEMS 24.8±13.5 vs. GEMS 21.7±18.0) and more frequently suffered traumatic shock (SBP sys <90mmHg: HEMS 18.3% vs. GEMS 14.8%). However, logistic regression analysis revealed that HEMS rescues resulted in an overall survival benefit compared to GEMS (OR 0.81, 95% CI [0.75-0.87], p<0.001, Nagelkerke's R squared 0.526, area under the ROC curve 0.922, 95% CI [0.919-0.925]). Analysis of specific subgroups demonstrated that patients aged older than 55 years (OR 0.62, 95% CI [0.50-0.77]) had the highest survival benefit after HEMS treatment. Furthermore, HEMS rescue had the most significant impact after 'low falls' (OR 0.68, 95% CI [0.55-0.84]) and in the case of minor severity injuries (ISS 9-15) (OR 0.66, 95% CI [0.49-0.88]).

CONCLUSIONS

In general, trauma patients benefit from HEMS rescue with in-hospital survival as the main outcome parameter. Focusing on special subgroups, middle aged and older patients, low-energy trauma, and minor severity injuries had the highest survival benefit when rescued by HEMS. Further studies are required to determine the potential reasons of this benefit.

Helicopter emergency medical services for adults with major trauma

BACKGROUND

Although helicopters are presently an integral part of trauma systems in most developed nations, previous reviews and studies to date have raised questions about which groups of traumatically injured people derive the greatest benefit.

OBJECTIVES

To determine if helicopter emergency medical services (HEMS) transport, compared with ground emergency medical services (GEMS) transport, is associated with improved morbidity and mortality for adults with major trauma.

SEARCH METHODS

We ran the most recent search on 29 April 2015. We searched the Cochrane Injuries Group's Specialised Register, The Cochrane Library (Cochrane Central Register of Controlled Trials; CENTRAL), MEDLINE (OvidSP), EMBASE Classic + EMBASE (OvidSP), CINAHL Plus (EBSCOhost), four other sources, and clinical trials registers. We screened reference lists.

SELECTION CRITERIA

Eligible trials included randomized controlled trials (RCTs) and nonrandomized intervention studies. We also evaluated nonrandomized studies (NRS), including controlled trials and cohort studies. Each study was required to have a GEMS comparison group. An Injury Severity Score (ISS) of at least 15 or an equivalent marker for injury severity was required. We included adults age 16 years or older.

DATA COLLECTION AND ANALYSIS

Three review authors independently extracted data and assessed the risk of bias of included studies. We applied the Downs and Black quality assessment tool for NRS. We analyzed the results in a narrative review, and with studies grouped by methodology and injury type. We constructed 'Summary of findings' tables in accordance with the GRADE Working Group criteria.

MAIN RESULTS

This review includes 38 studies, of which 34 studies examined survival following transportation by HEMS compared with GEMS for adults with major trauma. Four studies were of inter-facility transfer to a higher level trauma center by HEMS compared with GEMS. All studies were NRS; we found no RCTs. The primary outcome was survival at hospital discharge. We calculated unadjusted mortality using data from 282,258 people from 28 of the 38 studies included in the primary analysis. Overall, there was considerable heterogeneity and we could not determine an accurate estimate of overall effect.Based on the unadjusted mortality data from six trials that focused on traumatic brain injury, there was no decreased risk of death with HEMS. Twenty-one studies used multivariate regression to adjust for confounding. Results varied, some studies found a benefit of HEMS while others did not. Trauma-Related Injury Severity Score (TRISS)-based analysis methods were used in 14 studies; studies showed survival benefits in both the HEMS and GEMS groups as compared with MTOS. We found no studies evaluating the secondary outcome, morbidity, as assessed by quality-adjusted life years (QALYs) and disability-adjusted life years (DALYs). Four studies suggested a small to moderate benefit when HEMS was used to transfer people to higher level trauma centers. Road traffic and helicopter crashes are adverse effects which can occur with either method of transport. Data regarding safety were not available in any of the included studies. Overall, the quality of the included studies was very low as assessed by the GRADE Working Group criteria.

AUTHORS' CONCLUSIONS

Due to the methodological weakness of the available literature, and the considerable heterogeneity of effects and study methodologies, we could not determine an accurate composite estimate of the benefit of HEMS. Although some of the 19 multivariate regression studies indicated improved survival associated with HEMS, others did not. This was also the case for the TRISS-based studies. All were subject to a low quality of evidence as assessed by the GRADE Working Group criteria due to their nonrandomized design. The question of which elements of HEMS may be beneficial has not been fully answered. The results from this review provide motivation for future work in this area. This includes an ongoing need for diligent reporting of research methods, which is imperative for transparency and to maximize the potential utility of results. Large, multicenter studies are warranted as these will help produce more robust estimates of treatment effects. Future work in this area should also examine the costs and safety of HEMS, since multiple contextual determinants must be considered when evaluating the effects of HEMS for adults with major trauma.

Patient and trauma center characteristics associated with helicopter emergency medical services transport for patients with minor injuries in the United States

BACKGROUND

Helicopter emergency medical services (EMS) transport is expensive, and previous work has shown that cost-effective use of this resource is dependent on the proportion of minor injuries flown. To understand how overtriage to helicopter EMS versus ground EMS can be reduced, it is important to understand factors associated with helicopter transport of patients with minor injuries.

OBJECTIVES

The aim was to characterize patient and hospital characteristics associated with helicopter transport of patients with minor injuries.

METHODS

This was a retrospective analysis of adults ≥18 years who were transported by helicopter to Level I/II trauma centers from 2009 through 2010 as identified in the National Trauma Data Bank. Minor injuries were defined as all injuries scored at an Abbreviated Injury Scale (AIS) score of <3. Patient and hospital characteristics associated of being flown with only minor injuries were compared in an unadjusted and adjusted fashion. Hierarchical, multivariate logistic regression was used to adjust for patient demographics, mechanism of injury, presenting physiology, injury severity, urban-rural location of injury, total EMS time, hospital characteristics, and region.

RESULTS

A total of 24,812 records were identified, corresponding to 76,090 helicopter transports. The proportion of helicopter transports with only minor injuries was 36% (95% confidence interval [CI] = 34% to 39%). Patient characteristics associated with being flown with minor injuries included being uninsured (odds ratio [OR] = 1.36, 95% CI = 1.26 to 1.47), injury by a fall (OR = 1.32, 95% CI = 1.20 to 1.45), or other penetrating trauma (OR = 2.52, 95% CI = 2.12 to 3.00). Being flown with minor injuries was more likely if the patient was transported to a trauma center that also received a high proportion of patients with minor injuries by ground EMS (OR = 1.89, 95% CI = 1.58 to 2.26) or a high proportion of EMS traffic by helicopter (OR = 1.35, 95% CI = 1.02 to 1.78). No significant association with urban-rural scene location or EMS transport time was found.

CONCLUSIONS

Better recognizing which patients with falls and penetrating trauma have serious injuries that could benefit from being flown may lead to the more cost-effective use of helicopter EMS. More research is needed to determine why patients without insurance, who are most at risk for high out-of-pocket expenses from helicopter EMS, are at higher risk for being flown when only having minor injuries. This suggests that interventions to optimize cost-effectiveness of helicopter transport will likely require an evaluation of helicopter triage guidelines in the context of regional and patient needs.

Retrospective review of injury severity, interventions and outcomes among helicopter and nonhelicopter transport patients at a Level 1 urban trauma centre

BACKGROUND

Air ambulance transport for injured patients is vitally important given increasing patient volumes, the limited number of trauma centres and inadequate subspecialty coverage in nontrauma hospitals. Air ambulance services have been shown to improve patient outcomes compared with ground transport in select circumstances. Our primary goal was to compare injuries, interventions and outcomes in patients transported by helicopter versus nonhelicopter transport.

METHODS

We performed a retrospective 10-year review of 14 440 patients transported to an urban Level 1 trauma centre by helicopter or by other means. We compared injury severity, interventions and mortality between the groups.

RESULTS

Patients transported by helicopter had higher median injury severity scores (ISS), regardless of penetrating or blunt injury, and were more likely to have Glasgow Coma Scale scores less than 8, require airway control, receive blood transfusions and require admission to the intensive care unit or operating room than patients transported by other means. Helicopter transport was associated with reduced overall mortality (odds ratio 0.41, 95% confidence interval 0.33-0.39). Patients transported by other methods were more likely to die in the emergency department. The mean ISS, regardless of transport method, rose from 12.3 to 15.1 (p = 0.011) during our study period.

CONCLUSION

Patients transported by helicopter to an urban trauma centre were more severely injured, required more interventions and had improved survival than those arriving by other means of transport.

Cost-effectiveness of helicopter versus ground emergency medical services for trauma scene transport in the United States

STUDY OBJECTIVE

We determine the minimum mortality reduction that helicopter emergency medical services (EMS) should provide relative to ground EMS for the scene transport of trauma victims to offset higher costs, inherent transport risks, and inevitable overtriage of patients with minor injury.

METHODS

We developed a decision-analytic model to compare the costs and outcomes of helicopter versus ground EMS transport to a trauma center from a societal perspective during a patient's lifetime. We determined the mortality reduction needed to make helicopter transport cost less than $100,000 and $50,000 per quality-adjusted life-year gained compared with ground EMS. Model inputs were derived from the National Study on the Costs and Outcomes of Trauma, National Trauma Data Bank, Medicare reimbursements, and literature. We assessed robustness with probabilistic sensitivity analyses.

RESULTS

Helicopter EMS must provide a minimum of a 15% relative risk reduction in mortality (1.3 lives saved/100 patients with the mean characteristics of the National Study on the Costs and Outcomes of Trauma cohort) to cost less than $100,000 per quality-adjusted life-year gained and a reduction of at least 30% (3.3 lives saved/100 patients) to cost less than $50,000 per quality-adjusted life-year. Helicopter EMS becomes more cost-effective with significant reductions in patients with minor injury who are triaged to air transport or if long-term disability outcomes are improved.

CONCLUSION

Helicopter EMS needs to provide at least a 15% mortality reduction or a measurable improvement in long-term disability to compare favorably with other interventions considered cost-effective. Given current evidence, it is not clear that helicopter EMS achieves this mortality or disability reduction. Reducing overtriage of patients with minor injury to helicopter EMS would improve its cost-effectiveness.

Does helicopter transport impact outcome following trauma?

Helicopter transport (HT) has evolved from military roots into a critical component of trauma systems throughout the world. Concerns over cost and safety continue to challenge the role of HT in the civilian setting. Despite this, recent evidence has demonstrated a survival advantage for trauma patients undergoing HT. For patients transported from the scene of injury, improved survival has been shown in several multicenter studies as well as evaluation of large national databases. Issues of overtriage, however, remain problematic for scene HT and represent a prime area for future research in helicopter emergency medical systems (EMS). Patients undergoing inter-facility transfer have also been shown to have improved outcomes over ground transport in terms of shorter transfer times and increased survival particularly in more severely injured patients. The benefits seen are likely a result of a combination of rapid transport, advanced medical capabilities, and accessibility to remote terrain. Several subgroups of patients undergoing HT have been the subject of study as well. Patients with severe head injury have consistently been shown to have superior outcomes over ground ambulance, attributable to improvements in airway management early in the course of their injury. Conversely, HT for urban and penetrating injury has not seen similar benefits, likely due to proximity of trauma centers and recent advancements in urban EMS systems. The benefits of including physicians in helicopter crews are less clear and vary by region and system. Helicopter transport for trauma does appear to improve outcomes for trauma patients, and optimizing utilization of this valuable resource will be key as the role of helicopter EMS continues to develop within trauma systems.

Statement of severe trauma management in France; teachings of the FIRST study

INTRODUCTION

The blunt trauma victim management is still a matter of debate and comparing studies involving different emergency medical services and health care organization remains fictitious. Hence, the French Intensive care Recorded in Severe Trauma (FIRST) was conducted in order to describe the severe blunt trauma management in France. The present paper aimed at recalling the main results of FIRST study.

METHODS

The FIRST study was based on a multicenter prospective cohort of patients aged 18 or over with severe exclusive blunt trauma requiring admission to university hospital care unit within the first 72h and/or managed by medical-Staffed Emergency Mobile Unit (SMUR). Multiple data were collected about patient characteristics, clinical initial status, typology of trauma and the main endpoints were 30-day mortality.

RESULTS

Sixty-one percent of trauma patients were road traffic victims and 30% were domestic, sport or leisure trauma. Patients who benefited from medical pre-hospital management were globally more severely injured than those who received basic life support care by fire brigades. Therefore, they were delivered more aggressive treatment in the pre-hospital setting and the median time for their hospital admission was lengthened. However, their 30-day mortality was significantly reduced. The probability of death was also decreased when casualties were transported by SMUR helicopter directly to the university hospital. In the in-hospital setting, the performance of a whole-body computed tomography (CT) was associated with a significant reduction in the mortality risk compared with a selective CT.

CONCLUSION

The FIRST study suggests the benefit of a medical management in the pre-hospital setting on the survival of trauma patients. The emergency physician (EP) expertise in the pre-hospital and initial hospital phases would lead to the concept of the appropriate care for the appropriate trauma patient. It also highlights the necessity to set up organized regional sectors of care and registries.

Survival benefit of helicopter emergency medical services compared to ground emergency medical services in traumatized patients

INTRODUCTION

Physician-staffed helicopter emergency medical services (HEMS) are a well-established component of prehospital trauma care in Germany. Reduced rescue times and increased catchment area represent presumable specific advantages of HEMS. In contrast, the availability of HEMS is connected to a high financial burden and depends on the weather, day time and controlled visual flight rules. To date, clear evidence regarding the beneficial effects of HEMS in terms of improved clinical outcome has remained elusive.

METHODS

Traumatized patients (Injury Severity Score; ISS≥9) primarily treated by HEMS or ground emergency medical services (GEMS) between 2007 and 2009 were analyzed using the TraumaRegister DGU® of the German Society for Trauma Surgery. Only patients treated in German level I and II trauma centers with complete data referring to the transportation mode were included. Complications during hospital treatment included sepsis and organ failure according to the criteria of the American College of Chest Physicians/Society of Critical Care Medicine (ACCP/SCCM) consensus conference committee and the Sequential Organ Failure Assessment (SOFA) score.

RESULTS

A total of 13,220 patients with traumatic injuries were included in the present study. Of these, 62.3% (n=8,231) were transported by GEMS and 37.7% (n=4,989) by HEMS. Patients treated by HEMS were more seriously injured compared to GEMS (ISS 26.0 vs. 23.7, P<0.001) with more severe chest and abdominal injuries. The extent of medical treatment on-scene, which involved intubation, chest and treatment with vasopressors, was more extensive in HEMS (P<0.001) resulting in prolonged on-scene time (39.5 vs. 28.9 minutes, P<0.001). During their clinical course, HEMS patients more frequently developed multiple organ dysfunction syndrome (MODS) (HEMS: 33.4% vs. GEMS: 25.0%; P<0.001) and sepsis (HEMS: 8.9% vs. GEMS: 6.6%, P<0.001) resulting in an increased length of ICU treatment and in-hospital time (P<0.001). Multivariate logistic regression analysis found that after adjustment by 11 other variables the odds ratio for mortality in HEMS was 0.75 (95% CI: 0.636 to 862).

CONCLUSIONS

Although HEMS patients were more seriously injured and had a significantly higher incidence of MODS and sepsis, these patients demonstrated a survival benefit compared to GEMS.

Does scene physiology predict helicopter transport trauma admission?

BACKGROUND

Helicopter transport (HT) is necessary in the management of civilian trauma; however, its significant expense underscores the need to minimize overuse and inefficiency. Our objective was to determine whether on-scene physiologic criteria predict appropriate triage in HT trauma patients.

METHODS

We performed a retrospective review of patients flown from the injury scene to the emergency department of a level 1 trauma center by a university HT service from January 2006 to December 2010. Demographics, mechanism of injury, scene revised trauma score (RTS), travel distance, trauma alert level, payer status, emergency department and hospital disposition, and injury severity scores were queried from the electronic medical record and Trauma Registry of the American College of Surgeons with similar data on patients admitted because of trauma by ground transport for comparison. Proper triage criteria were defined through by the American College of Surgeons Committee on Trauma.

RESULTS

We identified 2522 HT patients. Of these, 1491 (59%) were properly triaged and 1031 (41%) were overtriaged. Univariate analysis revealed that the mean scene RTS was significantly higher for over- versus proper triage (7.68 ± 0.67 and 6.97 ± 1.57 respectively, P < 0.001). Neither the scene RTS nor travel distance predicted the triage criteria in a regression model (odds ratio 0.37, 95% confidence interval 0.16-0.85, and odds ratio 0.67, 95% confidence interval 0.60-0.74, respectively). Compared with ground transport, admitted HT patients had significantly more blunt trauma, lower scene RTSs, higher injury severity scores, more intensive care unit and ventilator days, a longer length of stay, and a greater travel distance and were more likely to be intubated (P < 0.001).

CONCLUSIONS

The physiological criteria did not predict the triage status in HT trauma patients. Although >40% of HT patients were overtriaged, they were more severely injured and required greater institutional resources than did the ground transport patients. Overtriage by a helicopter transport program might be appropriate.

Helicopter emergency medical services for adults with major trauma

BACKGROUND

Although helicopters are presently an integral part of trauma systems in most developed nations, previous reviews and studies to date have raised questions about which groups of traumatically injured patients derive the greatest benefit.

OBJECTIVES

The purpose of this review is to determine if helicopter emergency medical services transport (HEMS) is associated with improved morbidity and mortality, compared to ground emergency medical services transport (GEMS), for adults with major trauma. The primary outcome was survival to hospital discharge. Secondary outcomes were quality-adjusted life years (QALYs) and disability-adjusted life years (DALYs).

SEARCH METHODS

Searches were run in CENTRAL, MEDLINE, EMBASE, CINAHL (EBSCOhost), SCI-EXPANDED, CPCI-S, and ZETOC in January 2012. Relevant websites were also searched, including controlled trials registers, HSRProj, the World Health Organization (WHO) ICTRP, and OpenSIGLE. Searches were not restricted by date, language, or publication status. Attempts were made to contact authors in the case of missing data.

SELECTION CRITERIA

Eligible trials included randomised controlled trials (RCTs) and non-randomised intervention studies. Non-randomised studies (NRS), including controlled trials and cohort studies, were also evaluated. Each study was required to have a GEMS comparison group. An injury severity score (ISS) > 15 or an equivalent marker for injury severity was required. Only adults aged 16 years or older were included.

DATA COLLECTION AND ANALYSIS

Three review authors independently extracted data and assessed the risk of bias of included studies. The Downs and Black quality assessment tool was applied for NRS. The results were analysed in a narrative review, and with studies grouped by methodology and injury type. A predefined subgroup was comprised of four additional studies that examined the role of HEMS versus GEMS for inter-facility transfer. Summary of findings tables were constructed in accordance with the GRADE Working Group criteria.

MAIN RESULTS

Twenty-five studies met the entry criteria for this review. Four additional studies met the criteria for a separate, predefined subgroup analysis of patients transferred to trauma centres by HEMS or GEMS. All studies were non-randomised studies; no RCTs were found. Survival at hospital discharge was the primary outcome. Data from 163,748 people from 21 of the 25 studies included in the primary analysis were available to calculate unadjusted mortality. Overall, considerable heterogeneity was observed and an accurate estimate of overall effect could not be determined. Based on the unadjusted mortality data from five trials that focused on traumatic brain injury, there was no decreased risk of death with HEMS (relative risk (RR) 1.02; 95% CI 0.85 to 1.23). Nine studies used multivariate regression to adjust for confounding, the five largest indicated a statistically significant increased odds of survival associated with HEMS. All Trauma-Related Injury Severity Score (TRISS)-based studies indicated improved survival in the HEMS group as compared to the Major Trauma Outcomes Study (MTOS) cohort; some studies showed survival benefits in both the HEMS and GEMS groups as compared to MTOS. No studies were found to evaluate the secondary outcome of morbidity as assessed by QALYs and DALYs. All four studies suggested a positive benefit when HEMS was used to transfer patients to higher level trauma centres. Overall, the quality of the included studies was very low as assessed by the GRADE Working Group criteria.

AUTHORS' CONCLUSIONS

Due to the methodological weakness of the available literature, and the considerable heterogeneity of effects and study methodologies, an accurate composite estimate of the benefit of HEMS could not be determined. Although five of the nine multivariate regression studies indicated improved survival associated with HEMS, the remainder did not. All were subject to a low quality of evidence as assessed by the GRADE Working Group criteria due to their non-randomised design. Similarly, TRISS-based studies, which all demonstrated improved survival, cannot be considered strong evidence because of their methodology, which did not randomize the use of HEMS. The question of which elements of HEMS may be beneficial for patients has not been fully answered. The results from this review provide motivation for future work in this area. This includes an ongoing need for diligent reporting of research methods, which is imperative for transparency and to maximise the potential utility of results. Large, multicentre studies are warranted as these will help produce more robust estimates of treatment effects. Future work in this area should also examine the costs and safety of HEMS, since multiple contextual determinants must be considered when evaluating the effects of HEMS for adults with major trauma.

A comparison of the treatment of severe injuries between the former East and West German States

BACKGROUND

The annual number of persons killed in road-traffic accidents in Germany declined by 36% from 2001 to 2008, yet official traffic statistics still reveal a marked difference in fatalities between the federal states of the former East and West Germany twenty years after German reunification.

METHODS

We retrospectively analyzed data from the Trauma Registry of the German Trauma Society (Deutsche Gesellschaft für Unfallchirurgie; TR-DGU). Patients receiving primary treatment that had an Injury Severity Score (ISS) of 9 or above were analyzed separately depending on whether they were treated in the former East Germany or the former West Germany.

RESULTS

Data were obtained from a total of 26 866 road-accident trauma cases. With Berlin excluded, 2597 cases (10.2%) were from the former East Germany (EG), and 22 966 (89.9%) were from the former West Germany (WG). The percentage of the population living in these two parts of the country is 16.7% and 83.3%, respectively. The two groups did not differ significantly in either the mortality of injuries (EG 15.8%, WG 15.7%) or in the standardized mortality rate (0.89 [EG] vs. 0.88 [WG]). Over the years 2002-2008, the mean time to arrival of the emergency medical services on the scene was 19 minutes (EG) vs. 17 minutes (WG), and the mean time to arrival in hospital was 76 minutes (EG) vs. 69 minutes (WG).

CONCLUSION

Among the hospitals whose cases are included in the TR-DGU, there is no significant difference between the former East and West Germany with respect to mortality or any other clinically relevant variable. Hypothetically, the higher rate of death from road-traffic accidents in the former East Germany, as revealed by national traffic statistics, might be attributable to a difference in the quality of care received by trauma patients, but no such difference was found. Other potential reasons for it might be poorer road conditions, more initially fatal accidents, and lower accessibility of medical care in less densely populated areas.

Accuracy of prehospital diagnosis and triage of a Swiss helicopter emergency medical service

BACKGROUND

Helicopter emergency medical services (HEMSs) have become a standard element of modern prehospital emergency medicine. This study determines the percentage of injured HEMS patients whose injuries were correctly recognized by HEMS physicians.

METHODS

A retrospective level III evidence prognostic study using data from the largest Swiss HEMS, REGA (Rettungsflugwacht/Guarde Aérienne), on adult patients with trauma transported to a Level I trauma center (January 2006-December 2007). National Advisory Committee on Aeronautics (NACA) scores and the Injury Severity Score (ISS) were assessed to identify severely injured patients. Injured body regions diagnosed by REGA physicians were compared with emergency department discharge diagnoses.

RESULTS

Four hundred thirty-three patients were analyzed. Median age was 42.1 years (interquartile range, 25.5-57.9). Three hundred twenty-three (74.6%) were men. Patients were severely injured, with an in-hospital NACA score of 4 or higher in 88.7% of patients and median ISS of 13. REGA physicians correctly recognized injuries to the head in 92.9%, to the femur in 90.5%, and to the tibia/fibula in 83.8% of patients. Injuries to these body regions were overdiagnosed in less than 30%. Abdominal injuries were missed in 56.1%, pelvic injuries in 51.8%, spinal injuries in 40.1%, and chest injuries in 31.2% of patients.

CONCLUSION

This study shows that patients are adequately triaged by REGA physicians reflected by a NACA score 4 or higher in 88.7% of patients and a median ISS of 13. However, recognition of injured body regions seems to be challenging in the prehospital setting. Prospective studies on specific training of HEMS physicians for recognition of these injuries (e.g., portable ultrasonography, telemedicine) might help in the future.

LEVEL OF EVIDENCE

Prognostic study, level III.

Helicopter emergency medical service inTehran, Iran: a descriptive study

OBJECTIVE

The study provides descriptive information regarding missions performed by Tehran helicopter emergency medical services (HEMS) during a 1-year period.

METHODS

All patients transferred by Tehran HEMS between March 2006 and March 2007 were enrolled in this descriptive study. Based on HEMS records, information was gathered on flight time, the number of patients transferred in each flight, and mission outcomes.

RESULTS

During the 1-year study, a total of 353 patients were transported via 138 helicopter flights to 4 medical care centers in Tehran. The mean flight time, the time from the initial call until the patient was delivered to a medical facility, was 36.56 ± 18.44 minutes.

CONCLUSION

Tehran HEMS is still far from attaining optimal values, particularly regarding flight time. More efforts are needed to improve the timing as a component of care and the quality of care provided by this system.

Is Helicopter Evacuation Effective in Rural Trauma Transport?

Helicopter transport for trauma remains controversial because its appropriate utilization and efficacy with regard to improved survival is unproven. The purpose of this study was to assess rural trauma helicopter transport utilization and effect on patient survival. A retrospective chart review over a 2-year period (2007–2008) was performed of all rural helicopter and ground ambulance trauma patient transports to an urban Level I trauma center. Data was collected with regard to patient mortality and Injury Severity Score (ISS). Miles to the Level I trauma center were calculated from the point where helicopter or ground ambulance transport services initiated contact with the patient to the Level I trauma center. During the 2-year period, 1443 rural trauma patients were transported by ground ambulance and 1028 rural trauma patients were transported by helicopter. Of the patients with ISS of 0 to 10, 471 patients were transported by helicopter and 1039 transported by ground. There were 465 (99%) survivors with ISS 0 to 10 transported by helicopter with an average transport distance of 34.6 miles versus 1034 (99.5%) survivors with ISS 0 to 10 who were transported by ground an average of 41.0 miles. Four hundred and twenty-one patients with ISS 11 to 30 were transported by helicopter an average of 33.3 miles with 367 (87%) survivors versus a 95 per cent survival in 352 patients with ISS 11 to 30 who were transported by ground an average of 39.9 miles. One hundred and thirty-six patients with ISS >30 were transported by helicopter an average of 32.8 miles with 78 (57%) survivors versus a 69 per cent survival in 52 patients with ISS > 30 who were transported by ground an average of 33.0 miles. Helicopter transport does not seem to improve survival in severely injured (ISS > 30) patients. Helicopter transport does not improve survival and is associated with shorter travel distances in less severely injured (ISS < 10) patients in rural areas. This data questions effective helicopter utilization for trauma patients in rural areas. Further study with regard to helicopter transport effect on patient survival and cost-effective utilization is warranted.

Technological advancements in the care of the trauma patient

INTRODUTION

Medical technology has benefited many types of patients, but trauma care has arguably benefited more from technologic development than almost any other field.

METHODS

A literature review to identify key technological advances in the care of trauma patients was performed.

RESULTS

The advances in trauma care are in great measure due to the integration of many different systems. Medical technology impacts care in the field at the site of the trauma, in the transport to trauma facilities, and care at the trauma center itself. Once at the hospital, technology has impacted care in the trauma bay, intensive care units, the operating room, and in postoperative and long-term care settings. The integration of advancements, however, needs to be examined in a careful systematic fashion to insure that patients will actually derive benefit.

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.

Incidents, accidents and fatalities in 40 years of German helicopter emergency medical system operations

CONTEXT

Currently, approximately 100 000 helicopter emergency medical service (HEMS) missions for patients are undertaken in Germany each year. Compared to the early years, risk has reduced significantly, but is still higher than commercial aviation or other airborne operations.

OBJECTIVE

The aim of the present study was to evaluate helicopter accidents and fatalities related to HEMS operations.

DESIGN

Retrospective study of HEMS accidents in Germany.

SETTING

Analysis of accidents in the published flight accident reports of the German Federal Agency for Flight Accident Investigation (40-year period from 1970 to 2009). Data were collected by telephone interview with the operators, manual search of publications and by supplemental internet information.

MAIN OUTCOME MEASURES

Data were analysed per 10 000 missions. For statistical analysis, Fisher[Combining Acute Accent]s exact test was used. A P value less than 0.05 was considered significant.

RESULTS

During the period analysed, a total of 1.698 million HEMS missions (1970 vs. 2009: 61 vs. 98 471) were flown by a mean of 50 ± 27 (1 vs. 81) helicopters. To date, missions resulted in a total of 99 accidents with a mean of 2.4 ± 1.7 accidents per year (range 0-7). The accident rate was 0.57 (0-11.4) per 10 000 missions and the fatal accident rate was 0.11 (0-0.5). Some 64% of missions did not result in any injuries to occupants, whereas 19.2% were fatal. From the accidents analysed, 43.4% were due to collision with an obstacle during landing, take-off or hovering. Landing was the phase of flight most often associated with accidents (44.4%).

CONCLUSION

The present study is the largest on HEMS accidents and the only one analysing an entire 40-year time course beginning with inception. In comparison to previous data, a significantly lower accident rate per 10 000 missions was found. Gathering data on the early years is nearly impossible, and further analysis is required to calculate the risk of fatality or identify injury patterns.

Helicopter EMS: Research Endpoints and Potential Benefits

Patients, EMS systems, and healthcare regions benefit from Helicopter EMS (HEMS) utilization. This article discusses these benefits in terms of specific endpoints utilized in research projects. The endpoint of interest, be it primary, secondary, or surrogate, is important to understand in the deployment of HEMS resources or in planning further HEMS outcomes research. The most important outcomes are those which show potential benefits to the patients, such as functional survival, pain relief, and earlier ALS care. Case reports are also important "outcomes" publications. The benefits of HEMS in the rural setting is the ability to provide timely access to Level I or Level II trauma centers and in nontrauma, interfacility transport of cardiac, stroke, and even sepsis patients. Many HEMS crews have pharmacologic and procedural capabilities that bring a different level of care to a trauma scene or small referring hospital, especially in the rural setting. Regional healthcare and EMS system's benefit from HEMS by their capability to extend the advanced level of care throughout a region, provide a "backup" for areas with limited ALS coverage, minimize transport times, make available direct transport to specialized centers, and offer flexibility of transport in overloaded hospital systems.

Association of direct helicopter versus ground transport and in-hospital mortality in trauma patients: a propensity score analysis

OBJECTIVES

Helicopter emergency medical services (HEMS) transport of trauma patients has been used for decades. Its use, however, is still a subject of debate, including issues such as high costs, increasing numbers of crashes, and conflicting results regarding effectiveness in reducing mortality. The aim of this study was to examine whether mode of transport (HEMS vs. ground EMS) is independently associated with mortality among trauma patients transported directly from the scene of injury to definitive care.

METHODS

All trauma patients transported directly to a Level I or Level II trauma center by either air or ground EMS over a 4-year period were selected from the Oklahoma State Trauma Registry. Multivariable logistic regression was used to develop propensity scores based on variables measured at the scene of injury. The propensity scores represented the predicted probabilities of a patient being transported by HEMS given a specific set of characteristics and were used as a composite confounding variable in subsequent models of the association of mortality and mode of transport. Along with the propensity scores, Injury Severity Scores (ISS), initial Revised Trauma Score (RTS), and distance from the trauma center were included in a Cox proportional hazards model of the association of mode of transport and 24-hour and 2-week mortality.

RESULTS

Overall, the hazard ratio (HR) for 2-week mortality in patients transported by HEMS was 33% lower (HR = 0.67, 95% confidence interval [CI] = 0.54 to 0.84) than in patients transported by ground EMS from the scene of injury, after adjustment for the propensity score and other covariates. In subanalyses, the apparent association of a reduction in the hazard of early mortality among patients transported by HEMS was most evident for patients with an RTS based on injury scene vital signs of 3 to 7 (HR = 0.61, 95% CI = 0.46 to 0.82). The point estimate of the HR was similar (HR = 0.65 95% CI = 0.34 to 1.2) in the 75% of cases who had normal vital signs at the scene of injury, although it was no longer statistically significant because crude mortality was very low (1.7%) in this group. Among those with a RTS of 3 or less at the scene, crude mortality was 58%, and mode of transport was not associated with mortality (HR = 1.02, 95% CI = 0.68 to 1.6).

CONCLUSIONS

Helicopter EMS transport was associated with a decreased hazard of mortality among certain patients transported from the scene of injury directly to definitive care. Refinements in scene triage and transport guidelines are needed to more effectively select patients that may benefit from HEMS transport from those unlikely to benefit.

Trauma-related dispatch criteria for Helicopter Emergency Medical Services in Europe

INTRODUCTION

Helicopter Emergency Medical Services (HEMS) are used worldwide in order to provide potentially life-saving pre-hospital medical support to trauma patients at the accident scene. It is currently unclear how much overlap exists regarding the number and type of dispatch criteria used by individual HEMS organisations. The aim of the current study was to provide an overview of dispatch criteria for trauma cases used by HEMS organisations within Europe, and search for similarities and differences, between countries and HEMS stations.

MATERIALS AND METHODS

HEMS dispatch criteria related to trauma care were obtained from the literature and divided into four groups of criteria and processed in a questionnaire. HEMS providing organisations were identified and contacted by telephone and via email.

RESULTS

Fifty-five of the 65 organisations (85%) that were contacted completed the questionnaire. The criteria "Fall from height", "Lengthy extrication and significant injury" and "Multiple casualty incidents" were used most frequently. Criteria from the subgroup "Patient Characteristics-Co-morbidities and Age" were used the least. In 44 of the organisations the Central Dispatch Centre (CDC) was primarily responsible for HEMS dispatch.

CONCLUSION

This overview demonstrates the lack of uniformity in the use of dispatch criteria for trauma assistance on a national and international level. Furthermore, the activation of HEMS is not only depending on dispatch criterion protocols, but is also influenced by organisational factors like the education of the dispatcher, the training of the EMS personnel, the familiarity with the dispatch criteria, and the responses of bystanders. Future research should aim to identify a general set of criteria with the highest discriminating potential.

Helicopter emergency medical services utilization for winter resort injuries

INTRODUCTION

Helicopter and ground emergency medical services (EMS) units are frequently called to transport patients from winter resorts to area trauma centers.

OBJECTIVE

The purpose of this study was to examine helicopter EMS (HEMS) utilization for such patients, and to investigate out-of-hospital clinical variables that might help providers determine the most appropriate utilization of HEMS.

METHODS

The study included patients aged ≥ 12 years who were transported by ground EMS (GEMS) or HEMS to a regional trauma center with an acute injury sustained at a winter resort. The decision to transport via HEMS was based on field provider judgment. Injury information was prospectively obtained and combined with emergency department (ED) and hospital data abstracted from trauma registry and hospital records. For the purpose of this study, appropriate HEMS utilization was defined according to two different schemes. Limited utilization of HEMS was defined as the need for an emergent ED or out-of-hospital intervention (intubation, chest tube or needle thoracostomy, central line placement, or cardiopulmonary resuscitation). Expanded utilization of HEMS was defined as the need for an emergent intervention and/or an Injury Severity Score (ISS) ≥ 16 and/or need for emergent nonorthopedic surgery. Provider judgment alone was compared with results of recursive partitioning to predict the need for HEMS.

RESULTS

Of 815 patients enrolled between 2006 and 2009, 65 (8.0%) patients met the expanded criteria for appropriate HEMS utilization. Of these, 30 (46.2%) were transported by GEMS and 35 (53.8%) were transported by HEMS. Twenty-seven of the 65 patients (41.5%) required an emergent ED or out-of-hospital intervention. Activation of HEMS by out-of-hospital providers was (at best) 55.6% sensitive and 89.1% specific (85.2% overtriage rate) for predicting the need for an emergent out-of-hospital or ED intervention. Recursive partitioning, using a Glasgow Coma Scale score (GCS) ≤ 13 or pulse oximetry value <89%, was superior to provider judgment in predicting the need for an emergent procedure (57.9% sensitive, 98.6% specific, 45% overtriage rate).

CONCLUSION

Use of a simple prediction rule was superior to provider judgment in predicting the need for an emergent ED or out-of-hospital procedure in patients injured at winter resorts. If validated, this rule may be a resource to help out-of-hospital providers decide when to activate HEMS in these unique areas.

Factors at the scene of injury associated with air versus ground transport to definitive care in a state with a large rural population

BACKGROUND

Once emergency medical services (EMS) personnel decide to transport a trauma patient directly to definitive care, the next key decision at the scene of injury is whether to transport by air or ground.

OBJECTIVE

The aim of this study was to identify factors at the scene of injury that are associated with this decision.

METHODS

All trauma patients transported directly to a level I or level II trauma center by either air or ground EMS over a four-year period were selected from the Oklahoma State Trauma Registry. Initial scene vital signs, Glasgow Coma Scale score (GCS), injury mechanism, anatomic triage criteria, age, time of day, ground EMS service level, and scene location were collected. Scene location ZIP code centroids were geocoded and used to calculate distance to the trauma center. Following bivariate analyses, multivariable logistic regression models were developed within three strata defined by distance (>35, 16-35, and <16 miles).

RESULTS

More than 80% of the patients beyond 35 miles were transported by air, compared with 32% from 16-35 miles and only 4% from <16 miles. Regardless of distance, patients transported by helicopter tended to be younger, more often had abnormal vital signs, and more frequently came from areas served by a basic or intermediate ground EMS agency, as compared with patients transported by ground. Within each distance stratum, patients injured in severe motor vehicle crashes, motorcycle crashes, or pedestrian incidents were more likely to be transported by air. A GCS <14 was the only patient-related factor consistently associated with increased odds of air transport.

CONCLUSION

Distance is the main factor in deciding whether to use air or ground EMS to transport a trauma patient from the scene of injury to a trauma center. With the exception of GCS <14, injury etiology was more strongly and consistently associated with the decision to transport by air than were patient related-factors. Identifying factors influencing the field transport decision will help develop transport guidelines that make efficient use of EMS resources.

Helicopter evacuation of trauma victims in Los Angeles: does it improve survival?

BACKGROUND

The purpose of this study was to investigate the relationship between the method of transport after injury and survival among trauma patients admitted to a Level 1 trauma facility in Los Angeles, California.

METHODS

The trauma registry of LAC+USC Medical Center was reviewed to identify all injured patients evacuated by emergency medical service (EMS) from the injury scene from 1998 to 2007. The study population was divided into those who were airlifted (HEMS) and those who were transported by ground emergency medical service (GEMS) with transportation time that exceeded 30 minutes (GEMS > 30 minutes).

RESULTS

During the 10-year study period, 1,836 patients were airlifted (helicopters for emergency medical service (HEMS)) and 1,537 patients were ground transported (GEMS > 30 minutes). HEMS patients suffered more frequently a penetrating injury (19% vs. 11%, p < 0.001), presented more often hypotensive to the emergency department (4% vs. 1%, p < 0.001), had more frequently a Glasgow Coma Scale (GCS) < or = 8 (9% vs. 3%, p < 0.001) and required more often an intubation at the injury scene (1.6% vs. 0.4%, p < 0.001). However, the transportation time and the total prehospital time were significantly shorter for airlifted patients. After multivariable analysis, the difference in mortality between the two transport modalities was not significant (adjusted odds ratio (95% confidence interval, 0.72 (0.22, 2.35); p = 0.596).

CONCLUSIONS

In a metropolitan Los Angeles trauma system, EMS helicopter transportation of injured patients does not appear to improve overall adjusted survival after injury. There is however a potential benefit for severely injured subgroups of patients due to the shorter prehospital times.

Landing sites and intubation may influence helicopter emergency medical services on-scene time

BACKGROUND

Reduced transport time of patients from the scene of an accident to definitive surgical treatment is one important reason to employ ambulance helicopters on trauma missions. However, if the helicopter is unable to land close to the scene, the transport time may be increased compared to transport with ground ambulance, due to time-consuming transfer of the patient between vehicles.

OBJECTIVE

The objective of this study was to evaluate how the landing site, as determined by distance from the scene, and rapid sequence intubation (RSI) affected on-scene time (OST).

METHODS

This was a prospective observational study performed during a 12-month period in a mixed urban and rural anesthesiologist-staffed Helicopter Emergency Medical Service in Norway. Data regarding the landing sites, the accident, and patient treatment were recorded.

RESULTS

A total of 252 primary trauma missions were included in the study. In 75% of the missions, the aircraft landed<50 meters from the scene, and in 7% the distance exceeded 200 meters. Mean OST when the patient was not intubated was 14.5 min (median 14 min). When an RSI was performed, the mean OST was significantly higher (22.7 min, median 20 min; p<0.001).

CONCLUSION

Usually, a helicopter can land close to the accident scene and the location of the landing site does not contribute to a delay in arrival of the patient at the hospital. The OST is significantly higher, however, in those patients who receive endotracheal intubation before take-off. This reflects the time needed for intubation, as well as the increased complexity and workload when the patient is severely injured.

Helicopter emergency medical services accident rates in different international air rescue systems

Aim

Each year approximately two to four helicopter emergency medical services (HEMS) crashes occur in Germany. The aim of the present study was to compare crash rates and fatal crash rates in Germany to rates in other countries.

Materials and methods

A MEDLINE search from 1970 to 2009 was performed using combinations of the keywords “HEMS”, “rescue helicopter”, “accident”, “accident rate”, “crash”, and “crash rate”. The search was supplemented by additional published data. Data were compared on the basis of 10,000 missions and 100,000 helicopter flying hours. These data were allocated to specific time frames for analyis.

Results

Eleven relevant studies were identified. Five studies (three from Germany, one from the US, one from Australia) analyzing HEMS accidents on the basis of 10,000 missions were identified. Crash rates per 10,000 missions ranged between 0.4 and 3.05 and fatal crash rates between 0.04 and 2.12. In addition, nine studies (six from the US, two from Germany, one from Australia) used 100,000 flying hours as a denominator. Here, crash rates ranged between 1.7 and 13.4 and fatal crash rates between 0.91 and 4.7.

Conclusions

Data and accident rates were inhomogeneous and differed significantly. Data analysis was impeded by publication of mean data, use of different time frames, and differences in HEMS systems.