Medical Helicopter Accidents in the United States: A 10-Year Review

Use of Ultrasonography to Avoid an Unnecessary Procedure in the Prehospital Combat Environment: A Case Report

The role of ultrasonography in the prehospital combat setting has become a useful tool for triage, diagnosis, and treatment. Recent literature has demonstrated that ultrasonography has a greater sensitivity and specificity than clinical examination and plain radiography for pneumothorax detection in trauma patients, particularly small pneumothoraces. This becomes especially critical in austere and remote environments. Although many pneumothoraces are initially considered non-life-threatening, austere and combat environments possess additional risks of limited supplies, multiple casualties, and prolonged evacuation times that may potentially increase the morbidity of these injuries. This case report discusses the role of ultrasonography in pneumothorax detection in the prehospital combat environment.

Air Medical Transport of Trauma Patients

This report reviews the current status of air medical transportation of trauma patients. Aspects reviewed include patient care, dispatch, safety, and possible future directions in air medical patient care.

Air medical response to traumatic brain injury: a computer learning algorithm analysis

BACKGROUND

The role of air medicine in traumatic brain injury (TBI) has been studied extensively using trauma registries but remains unclear. Learning algorithms, such as artificial neural networks (ANN), support vector machines (SVM), and decision trees, can identify relationships between data set variables but are not empirically useful for hypothesis testing.

OBJECTIVE

To use ANN, SVM, and decision trees to explore the role of air medicine in TBI.

METHODS

Patients with Head Abbreviated Injury Score 3+ were identified from our county trauma registry. Predictive models were generated using ANN, SVM, and decision trees. The three best-performing ANN models were used to calculate differential survival values (actual and predicted outcome) for each patient. In addition, predicted survival values with transport mode artificially input as "air" or "ground" were calculated for each patient to identify those who benefit from air transport. For SVM analysis, chi was used to compare the ratio of unexpected survivors to unexpected deaths for air- and ground-transported patients. Finally, decision tree analysis was used to explore the indications for various transport modes in optimized survival algorithms.

RESULTS

A total of 11,961 patients were included. All three learning algorithms predicted a survival benefit with air transport across all patients, especially those with higher Head Abbreviated Injury Score or Injury Severity Score values, lower Glasgow Coma Scale scores, or hypotension.

CONCLUSION

Air medical response in TBI seems to confer a survival advantage, especially in more critically injured patients.

Transfer of Pediatric Trauma Patients to a Tertiary Pediatric Trauma Centre: Appropriateness and Timeliness

OBJECTIVE

To study the appropriateness of, and time taken, to transfer pediatric trauma patients in New South Wales to The Children's Hospital at Westmead (CHW), a pediatric trauma center.

METHODS

All trauma patients transferred to CHW from June 2003 to July 2004 were included in the study. Indications and time periods relevant to the transfer of the patient from the referring institute were retrieved and analyzed. Pediatric and adult retrieval services were compared.

RESULTS

Three hundred ninety-eight patients were transferred to CHW, of whom 332 were from the metropolitan region. Falls and burns were the commonest mechanism of injury. Burn was the commonest indication for transfer (107 of 398). Mean Injury Severity Score was eight. Nearly half the patients had minor injuries (Injury Severity Score<9). Patients spent an average of 5 hours at the referring hospital. Pediatric retrieval ambulances had significantly longer mean transfer times than did nonpediatric ambulance services with a total time spent of about 2.64 hours versus 1.30 hours, respectively. For aeromedical transfers, on the other hand, the difference between pediatric retrieval services and nonpediatric air ambulances was not significant.

CONCLUSIONS

The majority of the patients transferred had minor injuries. Pediatric trauma patients spend considerable time in their referring hospitals. Pediatric retrieval services appear to take significantly longer to transfer patients than nonpediatric ambulance transfers even after allowing for patient age and injury severity. Although this did not result in mortality or morbidity, there appears to be considerable scope for a reduction in transfer times through better coordination of these services.

Medically appropriate use of helicopter EMS: the mission acceptance/triage process

INTRODUCTION

Appropriate use of helicopter emergency medical services (HEMS) ensures the maximum impact of a limited resource on improved health outcomes. Overtriage increases real and opportunity costs and may unjustifiably expose the program to small but inherent safety risks. The purpose of this study is to describe the mission acceptance process for an integrated, provincially based HEMS program and determine its utilization patterns.

METHODS

This is a retrospective review of patient care and administrative databases. All missions were reviewed to determine whether they were medically appropriate. "Appropriateness" was defined a priori as requiring admission to a critical care unit, death during transportation or in first 24 hours, or in the case of trauma, an injury severity scale (ISS) score > or = 12. Overtriage was defined as not meeting these a priori definitions.

RESULTS

Five hundred eighty-four missions were reviewed from March 31, 2003 through December 31, 2004. Our mission acceptance process consists of three distinct but complementary phases: ongoing outreach education, scanning by dispatchers in an integrated dispatch center, and a clinician to online physician discussion about each case. The overall overtriage rate was 13.1%.

CONCLUSION

The rate of medically appropriate missions in this system is relatively high. Prospective research is required to improve HEMS triage systems.

Results and recommendations from the helicopter EMS pilot safety survey 2005

INTRODUCTION

In 2005, the Pilot Safety Study Group (PSSG), consisting of members of the Association of Air Medical Services Research Committee, wrote, distributed, and analyzed a survey of helicopter pilots regarding their knowledge, attitude, and perspectives on safety in the field of air medical transport.

METHODS

The Pilot Safety Survey 2005 (PSS2005) was based on another survey--one that was sponsored by Helicopter Association International (HAI) and National EMS Pilots Association (NEMSPA) and administered to pilots in 2001. The PSS2005 pared questions down so that the survey could be completed in 15 minutes on the internet, and the answers were organized in a manner to simplify analysis. An electronic link to the survey was distributed in a non-randomized fashion to HEMS pilots using the mailing lists of various operators and HEMS programs. Questions were clustered into eight groupings of safety, with a majority of responses being categorical, lending themselves to cross-tabulations.

RESULTS

The information gathered indicated that Helicopter EMS (HEMS) pilots are very experienced, with the average pilot logging 6,625 flight hours. Collectively, they took responsibility for HEMS accidents; with 92% of total respondents citing "pushing weather minimums" and 82% citing "pilot decision making" as the main reasons for crashes. Crew resource management (CRM) was well appreciated by the pilots; there appeared to be a positive correlation with programs that offer their employees CRM and the pilots' general perspective on safety. The survey was also clear that amongst 40% of the respondents, mission-oriented training needs improvement, and 74% responded that more realistic training in flight simulators would improve safety overall. Finally, 57% of the pilots both desired night vision goggles or devices (NVG/NVD) and believed that their usage would improve safety in the field of air medical transport (55% vs 45%, P = .0025).

CONCLUSIONS

Although the recommendations from the PSS2005 are lacking in definite evidence for a decrease in HEMS crashes, we consider the direct input from pilots as critical in the absolute elimination of crashes in Helicopter EMS (Vision Zero). Pilots are, after all, the very ones held responsible for HEMS crashes. Based on these findings, the PSSG hopes that the HEMS community will incorporate the following recommendations into their standard practices. We recommend that all HEMS operators have annual and regular CRM training. We recommend that all HEMS pilots have annual and regular training in realistic flight simulators. Finally, we recommend that all HEMS aircraft be in possession of NVGs, and if this is not possible (eg, light pollution from a highly urbanized region or cost-benefit issues), then to have annual and regular mission-oriented nighttime training.

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.

EMS Helicopter Crashes: What Influences Fatal Outcome?

STUDY OBJECTIVE

In recent years, air transport of patients has been associated with disproportionate increases in crashes and deaths. We identify factors related to fatal outcome in air medical helicopter crashes and suggest preventive measures.

METHODS

This was a retrospective study using National Transportation Safety Board records for helicopter emergency medical services (EMS) crashes between January 1, 1983, and April 30, 2005. The main outcome measure was the percentage of air medical crashes resulting in 1 or more deaths.

RESULTS

There were 182 helicopter EMS crashes during the 22.3-year study period; 39% were fatal. One hundred eighty-four occupants died: 45% of the 44 patients and 32% of the 513 crewmembers. Fifty-six percent of crashes in darkness were fatal compared with 24% of crashes not in darkness. Seventy-seven percent of crashes in instrument meteorological conditions were fatal compared with 31% in visual conditions. Thirty-nine percent of all deaths occurred in crashes with postcrash fires; 76% of crashes with postcrash fire were fatal compared with 29% of other crashes. Multivariate logistic regression revealed that controlling for other factors, the odds of fatal outcome was increased by postcrash fire (odds ratio [OR] 16.1; 95% confidence interval [CI] 5.0 to 51.5], bad weather (OR 8.0; 95% CI 2.4 to 26.0), and darkness (OR 3.2; 95% CI 1.3 to 7.9).

CONCLUSION

Fatalities after helicopter EMS crashes are associated especially with postcrash fire and with crashes that occur in darkness or bad weather and can be addressed with improved crashworthiness and measures to reduce flights in hazardous conditions. Further studies will be necessary to determine which changes will decrease the fatal crash rate and which are cost effective.

How safe are HEMS-programmes in Germany?

INTRODUCTION

Recent accidents with helicopter emergency medical service (HEMS) aircraft raise the question how safe HEMS in Germany is and how accidents could be prevented.

MATERIALS AND METHODS

We surveyed all German HEMS-programmes and reviewed the data of the German Aviation Authority regarding accidents with HEMS.

RESULTS

An average German HEMS-programme encounters one accident leading to at least severe damage or loss of the helicopter in 26 operating years, one accident resulting in casualties in 65 operating years and one fatal accident in 111 operating years. The major causes of accidents were obstacle strikes during landing at the scene. Flying in bad weather conditions and lack of discipline were other factors contributing to HEMS-accidents.

CONCLUSION

HEMS-safety could be improved by special training programmes for pilots and HEMS-crewmembers to address the factors listed above. Safety training for doctors is recommended but we did not find support for the notion of changing the doctor's legal position of a passenger to a HEMS-crewmember.

The National EMS Research strategic plan

One of the eight major recommendations put forth by the National EMS Research Agenda Implementation Project in 2002 was the development of an emergency medical services (EMS) research strategic plan. Using a modified Delphi technique along with a consensus conference approach, a strategic plan for EMS research was created. The plan includes recommendations for concentrating efforts by EMS researchers, policy makers, and funding resources with the ultimate goal of improving clinical outcomes. Clinical issues targeted for additional research efforts include evaluation and treatment of patients with asthma, acute cardiac ischemia, circulatory shock, major injury, pain, acute stroke, and traumatic brain injury. The plan calls for developing, evaluating, and validating improved measurement tools and techniques. Additional research to improve the education of EMS personnel as well as system design and operation is also suggested. Implementation of the EMS research strategic plan will improve both the delivery of services and the care of individuals who access the emergency medical system.

Occupational injuries and stressors among Canadian air medical health care professionals in rotor-wing programs

INTRODUCTION

Air medical health care providers work in a unique environment that may affect occupational injury rates and patterns. Despite this knowledge, little high-quality evidence exists regarding occupational injuries specifically incurred by air medical health care professionals. We sought to characterize the epidemiology of occupational injuries experienced by Canadian rotor-wing health care providers.

METHODS

A survey was sent to the 4 rotor-wing programs in Canada. All crewmembers participating directly in patient care were asked to complete the survey detailing any acute occupational injuries sustained within the previous year. A series of both open- and closed-ended questions was used to collect participant demographics and information regarding any injuries sustained.

RESULTS

One hundred and six (40.6%) participants completed the survey. Three hundred and thirty acute injuries were reported. Hand lacerations and leg contusions were most prevalent (31 and 24 individuals incurred these injuries, respectively). Acute back injuries were also prevalent with 25 (23.6%) participants reporting at least one back injury. Overall, an injury rate of 3.2 injuries per person per year was reported. Lifting was cited as a common factor in injury (30 cases). Most injuries required little treatment, with only 17 needing physician intervention, and only 6 required more than 1 week off work.

CONCLUSION

Injuries among Canadian air medical crews are common, but fortunately, the majority are minor. Specific injury prevention strategies may focus on stretcher design, cabin ergonomics, and extremity protective equipment.