Differences in Mortality Rates Among Trauma Patients Transported by Helicopter and Ambulance in Maryland

Medevac Utilization and Patient Characteristics in Rural Alaska 2010 to 2018

OBJECTIVE

Little is known about medevac utilization in remote, rural Alaska where there is no road access and communities are reliant on medevacs for emergency care. With high financial costs and risks to flight crews, there is an urgent need to understand medevac utilization in rural Alaska. This article aimed to describe medevac utilization and patient characteristics over 9 years in the remote, air transport dependent in Alaska.

METHODS

Deidentified data (2010-2018) were obtained for all medevacs originating within the Yukon-Kuskokwim Delta. Descriptive statistics were calculated, and chi-square tests of independence were conducted to identify differences.

RESULTS

Four thousand nine hundred ninety-one medevacs were performed, averaging 555 (standard deviation = 67.7) per year. Medevacs for respiratory complaints were predominant for children, whereas trauma predominated for adults 18 to 40 years old. Traumatic injury was more common in males than females aged < 65 years but was more common in females than males aged ≥ 65 years. Significant variability occurred in medevacs based on the community and the hour of the day.

CONCLUSION

Medevacs are a critical part of health care in rural, remote Alaska but appear subject to clinical and nonclinical determinants. These baseline data provide a foundation for future studies aiming to increase medevac safety and provide decision-making support.

Belted driver fatalities: Time of death and risk by injury severity

PURPOSE

This is a descriptive study of the fatality risk by injury severity and time of death for lap-shoulder-belted drivers without ejection in modern vehicles. It also determined the body region for severe injuries experienced by belted drivers using the most recent federal crash data.

METHODS

1997-2015 NASS-CDS data were evaluated for fatally injured lap-shoulder-belted drivers without ejection in light vehicles of 1997+ model year (MY). The severity of injuries sustained by belted drivers was assessed by the Maximum Abbreviated Injury Scale (MAIS) and individual injuries by Abbreviated Injury Scale (AIS) and body region. The change in fatality risk with MAIS was fit with a Logist function. Time of death was determined using the variable DEATH, which is reported hourly in unequal intervals up to 24 h and then daily up to 30 days after the crash. The fraction (f) and cumulative fraction (F) of the deaths are reported for each time period up to 30 days. A power or logarithmic curve was fit to the data using the trendline functions in Excel.

RESULTS

The NASS-CDS sample included 20,610,000 belted drivers with 37,974 fatalities from 1997 to 2015. The fraction of driver deaths increased with maximum injury severity (MAIS). For example, 17.4% of drivers died within 30 days with MAIS 4 injury. Virtually all drivers (99.7%) died with MAIS 6 injury. The change in fatality risk with injury severity was r = [1 + exp^{(10.159 - 2.088MAIS)}]^-1, R² = 0.950. Overall, there were 19,772 driver deaths with MAIS 4-6 injury and 13,059 with MAIS 0-3 injury. In addition, 44.7% of driver deaths occurred within 1.5 h of the crash, 56.7% within 2.5 h, and 64.6% within 4.5 h after the crash. The cumulative fraction of the deaths (F) up to 30 days was fit with a logarithmic function. It was F = 0.0739ln(t) + 0.5302, R² = 0.976, for deaths after 3.5 h. There were 19,772 driver deaths with 52,130 AIS 4+ injuries. On average, the driver experienced 2.64 AIS 4+ injuries most commonly to the head (44.5%) and thorax (38.1%).

CONCLUSIONS

The risk for belted driver deaths exponentially increased with MAIS. A majority of deaths occurred within 2.5 h of the crash. On average, fatally injured drivers experienced 2.64 AIS 4+ injuries, primarily to the head and thorax.

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.

Critical care paramedics: where is the evidence? A systematic review

OBJECTIVES

Paramedic-delivered prehospital critical care is an established concept in a number of emergency medical services around the world and, more recently, has been introduced to the UK. This review identifies and describes the available evidence relating to paramedics who routinely provide prehospital critical care as primary scene response (critical care paramedics, or CCP).

METHODS

A systematic search of electronic databases was performed: CENTRAL, EMBASE, MEDLINE (through EMBASE and Web of Knowledge) and Web of Science (through Web of Knowledge).

RESULTS

The search identified 12 relevant publications, one of which was a randomised controlled trial. The remaining 11 were retrospective studies. Five studies compared CCPs with physician-led care. Three of these publications demonstrated improved outcomes with physician care, while two showed no difference. Four further publications examined CCPs versus non-physician-led care and found improved outcomes (two studies), mixed effects (one study) and no difference (one study) for CCPs. Finally, three publications addressed the addition of skills to CCP competencies. A randomised controlled trial of CCP rapid sequence induction (RSI) and tracheal intubation demonstrated improved neurologic outcomes. CCP tube thoracostomy was shown to have similar complication rates to the same procedure performed in the emergency department, while addition of a non-invasive ventilation protocol to CCP practice had no effect on long-term mortality.

CONCLUSIONS

There is limited evidence to support the concept of paramedic-delivered prehospital critical care. The best available evidence suggests a benefit from prehospital RSI carried out by CCPs in patients with severe traumatic brain injury, but the impact of CCPs remains unclear for many conditions. Further high-quality research in this area would be welcome.

The association between air ambulance distribution and trauma mortality

OBJECTIVE

To determine whether increasing distance between helicopter ambulance airbase and either home residence or referring facility is associated with an increased risk of injury-related mortality.

BACKGROUND

A dramatic increase in the absolute number and utilization of Helicopter Emergency Medical Services transports has occurred in the management of the critically injured patients. HEMS are resource intensive, and the most efficient geographic distribution of airbases necessary to improve patient outcomes is unknown.

METHODS

We performed a retrospective analysis of 244,293 adult trauma patients who were treated at a designated trauma center (TC) in Pennsylvania during the period 1997 to 2007, using the Pennsylvania Trauma Outcomes Study data set. We performed a multivariate analysis, adjusting for differences in case mix, to determine whether airbase proximity to either residence or referring facility is associated with injury-related mortality.

RESULTS

For patients residing distant (>20 miles) from a TC, increasing distance from an airbase is associated with an increased risk of death; for each mile, the risk of mortality increases by approximately 1% (adjusted odds ratio, 1.011; 95% confidence interval, 1.002-1.018; P = 0.02). There is no additional benefit to living close (<25 miles) to more than 1 airbase. However, most airbases are positioned near TC and other airbases. Despite the proliferation of helicopter ambulances, 18.1% of patients who did not live near a TC also did not live near airbase.

CONCLUSIONS

For individuals residing distant from a TC, proximity to 1 airbase is associated with reduced risk of death. No additional benefit is observed when airbases are positioned close to a TC or other airbases.

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.

Evacuation of wounded with intracranial injury to a hospital without neurosurgical service versus primary evacuation to a level I trauma centre

BACKGROUND

Several studies have shown that delay in neurosurgical intervention worsens the neurologic outcome. However, rapid evacuation of wounded sustaining intracranial injury (ICI) to the nearest hospital may have some advantages, as the nearest hospital ER may be a better environment to prevent a secondary brain injury than the ambulance. Also, evacuation to a referral centre of all the wounded suspected in the field to have ICI will result in high rates of over triage. In order to create a factual basis for triage and resource utilization of wounded with possible ICI, we measured the delay in neurosurgical intervention of wounded with ICI that were evacuated to a hospital without neurosurgery service, the Western Galilee Hospital (WGH), Naharia, Israel, and its impact on morbidity and mortality.

METHODS AND MATERIALS

A retrospective case-control study was conducted for a period of 29 months. The study population included wounded over the age of two years, sustaining blunt ICI as diagnosed by CT scan that were evacuated to the WGH and later transferred to a level 1 trauma centre, Rambam Health Care Campus (RHCC), Haifa. Wounded were included only if the abbreviated injury score (AIS) of any other body system did not exceed 2. A control group of 29 wounded (one per month) was matched by random selection of wounded who met the inclusion criteria, primarily evacuated to RHCC and underwent neurosurgical intervention. Demographic data, anatomical characteristics of the injury, physiological parameters of injury severity, treatment at the ER, the schedules of neurosurgical interventions, ICU and hospital stay and discharge destination were recorded. Comparison between the groups was performed by Chi-square test for nominal variables, Fisher's exact test for 2×2 contingency tables, and Student's t test for numeric variables. The statistical significance was set at 5% (p<0.05).

RESULTS

162 wounded that were evacuated to WGH and later transferred to RHCC were included in the study. 31(19.1%) of them required invasive neurosurgical intervention. The wounded that needed neurosurgical intervention were transferred earlier: 165.7 (SD 61.1) min on average from arrival to WGH to arrival RHCC, compared to 217.8 (SD 152.9) min for those who did not need any intervention (p<0.005). The demographic variables, injury characteristics, physiological parameters and ER treatment of the wounded that underwent neurosurgical intervention were similar whether the wounded were transferred from WGH or arrived directly to RHCC. The time passed until neurosurgical intervention, was significantly shorter for wounded admitted directly to RHCC: 2h and 13.9 min (133.9 (SD 71.9)min) on average from admission to intervention compared to 4h and 47.6 min (287.6 (SD 107.5)min) on average from WGH admission to neurosurgical intervention (p<0.001). Lengths of ICU stay and hospital stay were similar in both groups. Two patients from each group died. 12 wounded admitted directly to RHCC group and 8 wounded transferred from WGH were discharged to a neurological rehabilitation.

CONCLUSIONS

Only a minority of wounded with an intracranial bleeding require neurosurgical intervention, but primary evacuation of these wounded to a hospital with no neurosurgery service results in an unacceptable delay in neurosurgical intervention. In this study, we did not find that this delay had an influence on prognosis, but a larger sample and a prolonged follow up are probably needed. A faster neurosurgical intervention can be achieved by a direct evacuation from the field to a level 1 trauma centre, or by expedition of the transfer process.

Impact of prehospital mode of transport after severe injury: a multicenter evaluation from the Resuscitation Outcomes Consortium

BACKGROUND

There is ongoing controversy about the relative effectiveness of air medical versus ground transportation for severely injured patients. In some systems, air medical crews may provide a higher level of care but may require longer transport times. We sought to evaluate the impact of mode of transport on outcome based on analysis of data from two randomized trials of prehospital hypertonic resuscitation.

METHODS

Injured patients were enrolled based on prehospital evidence of hypovolemic shock (systolic blood pressure ≤70 mm Hg or systolic blood pressure = 71-90 mm Hg with heart rate ≥108 bpm) or severe traumatic brain injury (TBI; Glasgow Coma Scale score ≤8). Patient demographics, injury severity, and physiology were compared based on mode of transport. Multivariate logistic regression was used to determine the impact of mode of transport on 24-hour and 28-day survival for all patients and 6-month extended Glasgow Outcome Scale for patients with TBI, adjusting for differences in injury severity.

RESULTS

Included were 2,049 patients, of which 703 (34%) were transported by air. Patients transported by air were more severely injured (mean Injury Severity Score, 30.3 vs. 22.8; p < 0.001), more likely to be in the TBI cohort (70% vs. 55.4%; p < 0.001), and more likely blunt mechanism (94.0% vs. 78.1%; p < 0.001). Patients transported by air had higher rates of prehospital intubation (81% vs. 36%; p < 0.001), received more intravenous fluids (mean 1.3 L vs. 0.8 L; p < 0.001), and had longer prehospital times (mean 76.1 minutes vs. 43.5 minutes; p < 0.001). Adjusted analysis revealed no significant impact of mode of transport on survival or 6-month neurologic outcome (air transport-28-day survival: odds ratio, 1.11; 95% confidence interval, 0.82-1.51; 6-month extended Glasgow Outcome Scale score ≤4: odds ratio, 0.94; 95% confidence interval, 0.68-1.31).

CONCLUSION

There was no difference in the adjusted clinical outcome according to mode of transport. However, air medical transported more severely injured patients with more advanced life support procedures and longer prehospital time.

LEVEL OF EVIDENCE

III.

Transfer delay and in-hospital mortality of trauma patients in Pakistan

BACKGROUND

Mortality and morbidity in trauma remain a major problem in developing countries. Organized emergency response systems for transfer of trauma patients to hospitals are absent and the consequent delays could cause significant complications.

AIMS

This study assessed the outcomes as a result of hospital transfer and delays in trauma patients.

METHODS

The study was based on trauma patients presenting to the Aga Khan University Hospital (AKUH), Karachi, Pakistan from 1998 to 2005, meeting the trauma team activation criteria. Data were collected and entered in a Trauma Registry. The study focused on analyzing the outcomes of injury to delay in definitive treatment and survival.

RESULTS

Out of 978 patients, only 303 (30.9%) patients reached the emergency room (ER) within an hour. The mean time from injury occurrence to arrival in the ER was 4.7h. There was no significant difference in mortality between all patients presenting early and those with more than 1h delay (OR=0.9, 95% CI: 0.6, 1.5).

CONCLUSIONS

Transfer and delay in admission to a tertiary care center does not affect in-hospital mortality of trauma patients in a setting with no emergency response system. This may be due to self selection of patients who survive long enough to reach the hospital.

Validation of a prehospital trauma triage tool: a 10-year perspective

BACKGROUND

Triage of the trauma patient in the field is a complex and challenging issue, especially deciding when to use aeromedical transport. The American College of Surgeons Committee on Trauma recently defined an acceptable under-triage rate [seriously injured patient not taken to a trauma center (TC)] as 5%, whereas over-triage rates may be as high as 25% to 50%. Effective utilization of prehospital helicopter transport requires both accurate assessment of patients and effective communication. The rural county adjacent to our developed trauma system uses standardized triage criteria to identify patients for direct transport to our TCs. We hypothesized these criteria accurately identify major trauma victims (MTV) and further that communication could be simplified to expedite transport.

METHODS

Prehospital personnel use a MAP (mechanism, anatomy, and physiology) scoring system to triage trauma patients. Patients with > or = 2 "hits" are defined as MTV. In 2004, the triage policy was changed so that MTV would be transported directly to a TC without base hospital consultation (previously required). The Emergency Medical Services (EMS) Medical Director reviewed cases transported to the TC to determine the appropriateness of triage decisions (over- and under-triage using the American College of Surgeons Committee on Trauma definitions). Data were compared before and after this policy change.

RESULTS

For 2004 to 2006, we evaluated 676 air transports to TC and compared them to 468 in the prior 56 months. The overall transport rate increased slightly 7% to 10%. During the study period the over-triage rate was 31% compared with 21%, before the policy change. The MAP triage tool yielded a 93.8% sensitivity and a 99.5% specificity. Therefore, it determined the need for air-medical transport out of a rural environment into an established trauma system with > 90% accuracy.

CONCLUSIONS

Prehospital personnel can accurately use a trauma triage tool to identify MTV. Eliminating base station contact, a potential for introducing communication error, did increase over-triage but still well within accepted limits. The system change also resulted in the transport of a greater proportion of minor trauma patients who later proved to have major injuries.

[The influence of transportation mode on mortality in polytraumatized patients. An analysis based on the German Trauma Registry]

BACKGROUND

Thirty years after its introduction in Germany, the benefits of the helicopter emergency medical service (HEMS) compared to ground ambulances (GA) still remain unclear. The aim of this study was to evaluate the influence of helicopter transport on rescue time and mortality based on the data of the German Trauma Registry.

METHODS

Data from patients with multiple injuries were documented prospectively between 1993 and 2003 in different trauma centers in Germany, Switzerland, Austria and The Netherlands. From these data, patients with an injury severity score (ISS)<16 were excluded. Patients who were transported to the hospital without a physician were also excluded. The data from included patients were evaluated for time to hospital and influence of transportation service on mortality.

RESULTS

A total of 7,534 patients with multiple injuries were included. Of these, 3,870 patients were transported by HEMS and 3,664 reached the hospital by GA. There were 74.9% male patients in the HEMS group, and 71.3% male patients in the GA group. The mean ISS was higher in the HEMS group (31.4 vs 30.7; P<0.01); patients transported by GA were older (HEMS: 39.2; NEF:41.3; P<0.01). The GA arrived on the scene after 14.33 min, the HEMS after 18.18 min (P<0.01). Time at the scene was longer in the HEMS group (HEMS: 26:26 min; NEF: 22:29 min; P<0.01). Intubation rate in the HEMS group was about 80%, while patients transported by GA were intubated in 60% of cases. The overall mortality was 30.9%. Evaluation of the TRISS prediction of survival showed a benefit for patients transported with HEMS. In a multivariate analysis, intubated patients with ISS<or=60 had a lower mortality rate if transported with HEMS (NEF: 40.1%; HEMS 34.9%; P<0.01).

CONCLUSIONS

Only minor differences in age and ISS were found between the groups. The time between the accident and arrival of the physician was longer in the HEMS group. The HEMS group also remained on the scene for longer, but had a higher rate of intervention. According to our analysis of the German Trauma Registry, patients with multiple injuries benefit from HEMS transportation.

Pre-hospital trauma care

The chain of survival in outcome from major trauma is equally as important as its well established concept in survival from cardiac arrest. Preventive measures have been shown to be an effective means of reducing death from trauma, and the standard of pre-hospital care for those surviving the primary injury is improving in many trauma systems. The optimal pre-hospital interventions are still debated, but evidence suggests that patients with severe head injury in particular will benefit significantly from pre-hospital rapid-sequence intubation and field stabilization, whereas those with penetrating injury require rapid evacuation to hospital with minimal intervention. Pre-hospital asystole from trauma has a universally poor outcome. When delivering appropriate care, several helicopter-based systems have shown improvements in outcome compared with ground-based systems. The International Liaison Committee on Resuscitation recently published guidelines on resuscitation, with particular relevance to pre-hospital trauma care. The importance of bystander cardiopulmonary resuscitation, oxygenation, and the avoidance of iatrogenic morbidity are stressed.

Predictive effect of out-of-hospital time in outcomes of severely injured young adult and elderly patients

INTRODUCTION

The importance of accessing care within the first hour after injury has been a fundamental tenet of trauma system planning for 30 years. However, the scientific basis for this belief either has been missing or largely derived from case series from trauma centers. This study sought to determine the correlation between prehospital times and outcomes among severely injured elderly patients.

METHODS

This is a cross-sectional, observational study. All adults (> or = 18 years of age) with acute trauma as defined by The International Classification of Diseases Ninth Edition, Clinical Modification diagnostic codes and E-codes were included. Poisonings, single system burns, and late effects of injury were excluded. Chi-square and Student's t-test were used for significance testing. To assess the predictive effects of prehospital time and outcomes, three independent logistic regression models were constructed for both young and elderly groups, with hospital length of stay, mortality, and complications as individual dependent variables. Statistical significance was set at the 0.05 level.

RESULTS

Of 41,041 cases, 37,276 were > or = 18 years of age. Of the 1,866 with an Injury Severity Score (ISS) > 15, 1,205 were young and 661 elderly. Logistic regression results showed that prehospital time correlated significantly with hospital length of stay (p = 0.001) and complications (p = 0.016), but not with mortality (p = 0.264) among young patients, whereas in the elderly group pre-hospital time had no significant predictive effect for length of stay, complications, or mortality (p = 0.512, p = 0.512, and p = 0.954 respectively).

CONCLUSION

This population-based study has demonstrated that prehospital time correlates with length of stay and complications in young patients. In elderly patients, prehospital time failed to show correlation with any outcomes measured.

The effectiveness of video-telemedicine for screening of patients requesting emergency air medical transport (EAMT)

BACKGROUND

Demand for emergency air medical transport (EAMT) services have increased in recent years. However, the high costs of these services have raised questions on the benefit to patient outcomes. In this study, we evaluate the effectiveness of video-telemedicine for the preflight screening of patients for air medical transports.

METHOD

A prospective cohort study. Medical records of patients transported from the Penghu Islands to Taiwan were retrospectively collected from November 1999 to October 2002 (stage 1). In addition, we collected medical records of patients who were preflight-screened by physicians using video Web cameras from November 1, 2002 through August 30, 2003 (stage 2). The intervention in stage 2 included a set of protocols and screening criteria for EAMT implemented by the National Aeromedical Consultation Center (NACC). In stage 1, there were no standardized protocols or screening guidelines for EAMT. The EAMT system before implementing preflight screening and telemedicine was mostly based on patient's requests and their health condition determined by the treating medical officers (TMO).

RESULTS

A total of 822 transfers were included in this study. Patient demographic backgrounds in the two groups were similar on gender, age, disease classification, and types of illnesses. Patients in stage 2 were significantly older than those in stage 1. In a comparison of flight frequencies between the two stages, the results revealed a 36.2% reduction of EAMT applications in stage 2. The flight approval rate was 91.2%. The intervention in stage 2 also presented a significant reduction in cross-zone transport (16.1% to 0.1% to the northern Taiwan region). Within-zone transfers increased from 74.9% to 88.3%. Cost analysis showed that physician triage in stage 2 resulted in a total annual savings on EAMTs of US 448,986 dollars.

CONCLUSIONS

This study demonstrates the physician-assisted preflight screening using video-telemedicine significantly reduced the frequency of unnecessary air medical transports and consequently led to reduced costs. Video-telemedicine can be an essential tool to support physicians in decision-making for patient screening.

The Fastest Route Between Two Points is Not Always a Straight Line: An Analysis of Air and Land Transfer of Nonpenetrating Trauma Patients

BACKGROUND

The distance beyond which helicopter transport is faster than ground for interfacility transfer of trauma patients has not been established. Our objective was to determine whether such a threshold exists.

METHODS

A retrospective cohort study was conducted involving 243 patients transported by land and 139 patients by air from 13 sites during a 3-year period. Time intervals between critical events were compared for the two modes of transport at each site.

RESULTS

The time interval between the decision to transfer and the actual departure time was shorter for patients transferred by land from all sites studied (mean 41.3 versus 89.7 minutes, p < 0.001). The travel time was shorter by helicopter from all sites (mean 58.4 versus 78.9 minutes, p < 0.001). The time between the decision to transfer and the arrival at the trauma center was similar at most sites but faster by land overall (mean 120.3 versus 150.0 minutes, p = 0.014). No threshold was detected beyond which helicopter transport was superior.

CONCLUSIONS

Several factors other than the distance to be traveled determine the time required for interfacility transfer of trauma patients. A fixed distance threshold beyond which helicopter transport should be used does not exist. The decision as to which mode of transport to use for emergent trauma patient transfers should be based upon multiple factors including the distance traveled and ambulance availability, and must be individualized for each site that transfers patients.

Helicopter Scene Transport of Trauma Patients with Nonlife-Threatening Injuries: A Meta-Analysis

BACKGROUND

Helicopters have become a major part of the modern trauma care system and are frequently used to transport patients from the scene of their injury to a trauma center. While early studies reported decreased mortality for trauma patients transported by helicopters when compared with those transported by ground ambulances, more recent research has questioned the benefit of helicopter transport of trauma patients. The purpose of this study was to determine the percentage of patients transported by helicopter who have nonlife-threatening injuries.

METHODS

A meta-analysis was performed on peer-review research on helicopter utilization. The inclusion criteria were all studies that evaluated trauma patients transported by helicopter from the scene of their injury to a trauma center with baseline parameters defined by Injury Severity Score (ISS), Trauma Score (TS), Revised Trauma Score (RTS), and the likelihood of survival as determined via Trauma Score-Injury Severity Score (TRISS) methodology.

RESULTS

There were 22 studies comprising 37,350 patients that met the inclusion criteria. According to the ISS, 60.0% [99% confidence interval (CI): 54.5-64.8] of patients had minor injuries, According to the TS, 61.4% (99% CI: 60.8-62.0) of patients had minor injuries. According to TRISS methodology, 69.3% (99% CI: 58.5-80.2) of patients had a greater than 90% chance of survival and thus nonlife-threatening injuries. There were 25.8% (99% CI: -1.0-52.6) of patients discharged within 24 hours after arrival at the trauma center.

CONCLUSIONS

The majority of trauma patients transported from the scene by helicopter have nonlife-threatening injuries. Efforts to more accurately identify those patients who would benefit most from helicopter transport from the accident scene to the trauma center are needed to reduce helicopter overutilization.

The Impact of Aeromedical Response to Patients With Moderate to Severe Traumatic Brain Injury

STUDY OBJECTIVE

Aeromedical crews offer an advanced level of practice and rapid transport to definitive care; however, their efficacy remains unproven. Previous studies have used relatively small sample sizes or have been unable to adequately control for the effect of other potentially influential variables. Here we explore the impact of aeromedical response in patients with moderate to severe traumatic brain injury.

METHODS

This was a retrospective analysis using our county trauma registry. All patients with head Abbreviated Injury Score of 3 or greater were included; interfacility transfers were excluded. The impact of aeromedical response was determined using logistic regression, adjusting for age, sex, mechanism, preadmission Glasgow Coma Scale score, head Abbreviated Injury Score, Injury Severity Score, and the presence of preadmission hypotension. Propensity scores were used to account for variability in selection of patients to undergo air versus ground transport. Patients with moderate and severe traumatic brain injury, as defined by head Abbreviated Injury Score and Glasgow Coma Scale score, were compared. Finally, aeromedical patients undergoing field intubation were compared with ground patients undergoing emergency department (ED) intubation.

RESULTS

A total of 10,314 patients meeting all inclusion and exclusion criteria and with complete data sets were identified and included 3,017 transported by aeromedical crews. Overall mortality was 25% in the air- and ground-transported cohorts, but outcomes were significantly better for the aeromedical patients when adjusted for age, sex, mechanism of injury, hypotension, Glasgow Coma Scale score, head Abbreviated Injury Score, and Injury Severity Score (adjusted odds ratio [OR] 1.90; 95% confidence interval [CI] 1.60 to 2.25; P<.0001). Good outcomes (discharge to home, jail, psychiatric facility, rehabilitation, or leaving against medical advice) were also higher in aeromedical patients (adjusted OR 1.36; 95% CI 1.18 to 1.58; P<.0001). The primary benefit appeared to be in more severely injured patients, as reflected by head Abbreviated Injury Score and Glasgow Coma Scale score. Improved survival was also observed for air-transported patients intubated in the field versus ground-transported patients given emergency intubation in the ED (adjusted OR 1.42; 95% CI 1.13 to 1.78; P<.001).

CONCLUSION

Here we analyze a large database of patients with moderate to severe traumatic brain injury. Aeromedical response appears to result in improved outcomes after adjustment for multiple influential factors in patients with moderate to severe traumatic brain injury. In addition, out-of-hospital intubation among air-transported patients resulted in better outcomes than ED intubation among ground-transported patients. Patients with more severe injuries appeared to derive the greatest benefit from aeromedical transport.

Einfluss von Rettungsmittel und Zielklinik auf die Letalität nach Polytrauma

BACKGROUND

The aim of this study was to document the present knowledge from the medical literature on (1) efficacy of aeromedical evacuation (helicopter emergency medical service, HEMS) and (2) influence of the level of the first receiving hospital on mortality of patients.

METHODS

Systematic review of the literature between 1970 and 2003; identification of studies with an evidence level of at least III and included control group; own results.

RESULTS

(1) 17 studies concerning the efficacy of HEMS were included into the review. No single study yielded shorter rescue times with the use of HEMS. 11 of 17 studies showed a significantly higher survival rate (8.2 to 52%) with the employment of HEMS especially with mid-degree polytrauma. (2) All 6 relevant studies dealing with hospital level found a considerable lower mortality rate (19 to 42%) for patients treated primarily at a level 1 trauma center or comparable institution.

CONCLUSIONS

The analyzed studies showed a trend toward decreased mortality rates with the employment of HEMS. Considering the comparable hospital level and even longer rescue times with HEMS, these differences can be explained with higher quality of initial diagnosis and treatment of the HEMS rescue team. Furthermore, mortality rates can be lowered significantly through primary treatment at a level 1 trauma center. Thus, the more flexible choice of the first receiving hospital represents a specific, clinically relevant advantage of HEMS in emergency medicine.

Regional Air Transport of Burn Patients: A Case for Telemedicine?

BACKGROUND

Air transport of burn patients is plagued by frequent "overtriage." We examined the use of air transport and the feasibility of using alternative methods such as telemedicine to assist in evaluation and treatment of burn patients within our region.

METHODS

We reviewed all burn patients transported by air during 2000 to 2001. Each patient was classified as being most appropriate for air, ground, or family transport. In addition, a decision was made regarding whether telemedicine evaluation of the patient before transport could have significantly altered initial treatment decisions.

RESULTS

Two hundred twenty-five acutely burned patients were transferred from referring hospitals in nine states, at a mean distance of 246 air miles. Mean burn size calculated by burn center physicians was 19.7% total body surface area, whereas referring physicians' mean estimate was 29% total body surface area. In 92 cases, over- or underestimation of burn size by referring physicians of as much as 560% or decisions regarding performance of endotracheal intubation suggested that telemedicine evaluation before transport might have significantly altered transport decisions or care. Air transport charges exceeded hospital charges in 21 cases.

CONCLUSION

Frequent discrepancies in burn assessment contribute to overuse of air transport. The ability to evaluate burn patients by telemedicine may have the potential to assist decisions regarding transfer, avoid errors in initial care, and reduce costs. We are currently attempting to develop and test such a system.

The utility of helicopter transport of trauma patients from the injury scene in an urban trauma system

BACKGROUND

Continuing controversy surrounding the value of scene helicopter evacuation of urban trauma victims led to the present study.

METHODS

A retrospective review was performed of all patients brought to our trauma center from the injury scene by helicopter from 1990 to 2001.

RESULTS

The study included 947 consecutive patients, 911 with blunt trauma and 36 with penetrating injuries. The mean Injury Severity Score (ISS) was 8.9. Fifteen patients died in the emergency department, 312 patients (33.5%) were discharged home from the emergency department (mean ISS, 2.7), and 620 patients were hospitalized (mean ISS, 11.4). Three hundred thirty-nine of the hospitalized patients (54.7%) had an ISS < or = 9; 148 patients had an ISS > or = 16. Eighty-four patients (8.9%) required early operation, mostly for open extremity fractures; only 17 patients (1.8%) underwent surgery for immediately life-threatening injuries. For 54.7% of the patients, the helicopter was judged to be clearly faster than would have been possible by ground transport. In 140 additional patients (14.8%) with prolonged scene time, the helicopter was probably faster than ground ambulance. Considering faster transport time and either the need for early operation or hospitalization with an ISS > or = 9 as advantageous, a maximum of 22.8% of the study population possibly benefited from helicopter transport.

CONCLUSION

The helicopter is used excessively for scene transport of trauma victims in our metropolitan trauma system. New criteria should be developed for helicopter deployment in the urban trauma environment.

Trauma systems

Trauma is one of the major causes of death and disability in modern society, particularly for the young. Organized trauma systems reduce mortality and morbidity from trauma. An effective trauma system addresses all aspects of trauma care, from prevention to rehabilitation. Well-developed trauma systems are currently available only to a minority of the world's population. Trauma systems in developed nations have much potential for improvement.