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à : http://www.mja.com.au/public/issues/182_01_030105/hol10418_fm.html Safety of helicopter aeromedical transport in Australia: a retrospective study Jim Holland and David G Cooksley MJA 2005; 182 (1): 17-19 Abstract Objectives: To determine the accident rate for Australian helicopter emergency medical services (HEMS) per 100 000 flying hours and to determine the patient mortality risk per mission from a HEMS accident. Method: Retrospective observational study of Australian HEMS flying hours and accidents from 1992–2002. Results: The calculated accident rate for Australian HEMS is 4.38 per 100 000 flying hours. One patient died as a direct result of helicopter accident in 50 164 missions. Overall, one accident occurred every 16 721 missions. Conclusions: The overall Australian HEMS accident rate is similar to that reported from other countries, with all accidents occurring in Queensland community HEMS. Helicopters flown at night under Visual Flight Rules (VFR) appear to represent a high-risk subgroup. HEMS flights do not appear to present significant mortality risk to patients being transported. The first Australian helicopter emergency medical service (HEMS) began operations in Sydney in 1973. Since then, HEMS operations within Australia have grown considerably (see Box 1). HEMS programs now operate in all Australian states and territories except the Northern Territory. Benefits in morbidity and mortality have been reported with physician-staffed HEMS stabilisation and primary transport of trauma patients;1-3 however, the benefits for trauma patients4,5 as well as medical patients6-10 have been challenged. It is generally accepted in medicine that the risk of an intervention should not be greater than its demonstrated benefit. Unless the risk is known, it is impossible to realistically assess the risk–benefit of HEMS. To date, there has been no attempt to quantify the risks associated with HEMS operations in Australia. This article attempts to define the accident rate for HEMS operations and the patient mortality risk from a HEMS accident within Australia. Methods Australian HEMS operators listed in the “SAR, EMS and Police Directory”11 were contacted by mail, email and telephone, and asked to provide the following data for the period 1 January 1992 to 31 December 2002: the number of medical missions (primary and interhospital) flown, the number of patients transported, and the total number of flying hours engaged in (primary and interhospital) patient transport. Discussions with the listed HEMS operators and state ambulance services identified other users of helicopters for medical transport, such as the Northern Territory Aerial Service, and government agencies such as Queensland Emergency Services, who were then contacted and asked to provide the same data. Ad-hoc patient transports by commercial (non-HEMS) helicopter operators, as occurred in the Australian Capital Territory, Western Australia and the Northern Territory during the study period, were excluded. When the number of patient transports and the number of missions were not both reported, we assumed one patient transport per mission and vice versa. The number of accidents involving EMS helicopters during the same period was determined from Air Safety Occurrence Reports published by the aviation branch of the Australian Transport Safety Bureau. HEMS air-safety occurrences not associated with usual primary or interhospital patient transports, such as winch (hoist) operations and “search and rescue” missions, were excluded. Aviation accident rates are reported as fatal and total accidents per 100 000 flying hours.12-15 Data were collated and entered onto a standard spreadsheet format. The accident rate (per 100 000 flying hours) and patient mortality rate per mission were then calculated. The study was approved by the chairman of the Townsville Hospital and District Ethics Committee. Results We received data for all HEMS operations in Australia during the study period, with the exception of one Victorian community service provider who commenced operations in mid-1999. The numbers of missions, patients transported, flying hours and accidents for each year of the study period are shown in Box 1. A summary of HEMS activity by state is shown in Box 2. Calculated accident rates per 100 000 flying hours for Australia, Queensland government HEMS, and Queensland community HEMS are shown in Box 3. Published rates for the United States and the Federal Republic of Germany are included in Box 3 for comparison. The number of patients transported is generally less than the total number of missions. This is most likely because of missions being aborted or patients dying before transport. In Australia during the study period, only one patient, a 5-year-old boy, died as a direct result of a HEMS accident in 50 164 missions. He was accompanied by his mother, who also suffered fatal injuries in the crash, as did the pilot and two paramedics.18 Overall, one accident occurred every 16 721 missions. A summary of Australian HEMS accidents that occurred during the study period is provided in Box 4.18-20 Following the study period, another Queensland Community Rescue Service helicopter crashed into the sea north of Mackay, killing all three crew members. This occurred during a night flight to collect an injured patient on Hamilton Island.21 Details of this accident are also included in Box 4. Discussion The accident rate for HEMS in Australia is 4.38 per 100 000 flying hours for the period 1992–2002, which is similar to the reported international experience. All accidents within the study period involved Queensland community HEMS flying under Visual Flight Rules. Their accident rate was 25.03 per 100 000 flying hours, based on three accidents in 11 987 flying hours. During the same period, other HEMS operations in Australia accumulated a total of 56 448 accident-free flying hours. It is important to note that our data do not allow comparison of accident rates between Visual Flight Rules (VFR) and Instrument Flight Rules (IFR) HEMS flying hours (see Box 4 for definitions). It should also be noted that VFR HEMS operations are conducted in other parts of Australia — they are not limited to Queensland community HEMS. It has been stated that helicopter transport is expensive and risky, and that the benefits of helicopter transport must always be weighed against the risk of death for patients.22 The overall risk of accident-related patient death in Australia is about 1 in 50 000 HEMS missions. It is not known how this risk compares to other modes of patient transport, such as road ambulance or aeroplane, and further research is required in this area. Clinicians requesting patient transport should always consider whether any potential benefit to the patient is greater than the risk of the transport itself. Our data underestimate the number of HEMS missions, patients transported and hours flown, because one Australian HEMS operator did not provide data for the study period, and we did not include ad hoc patient transports by general aviation helicopter operators. Thus, our calculated accident rate will be higher than the actual rate. We believe this is unlikely to significantly affect our results. For example, correcting for an underestimation of flying hours by 5% would change the Australian HEMS accident rate from 4.38 to 4.19 per 100 000 flying hours. Another potential confounding variable is the assumption that one patient was transported per mission and vice versa when either of the variables was unknown. Several HEMS operators stated informally that it is unusual to transport more than one patient per mission. The effect of this potential error on the calculated “patient mortality per mission flown” is unknown. All air safety occurrences require mandatory reporting to the Air Transport Safety Bureau. We are therefore confident that all HEMS-related accidents occurring during the study period have been identified. Our study attempts to define risk associated with standard primary and interhospital patient transfers. We specifically excluded HEMS flying hours and air-safety occurrences not associated with standard transports, such as aerial winch (hoist) and “search and rescue” operations. We believe that such operations do not reflect the procedure and risk encountered with standard HEMS transport, and require separate risk assessment. Investigation of reasons for the high accident rate experienced by Queensland community HEMS is beyond the scope of this article and warrants further review. However, we note that three of the four HEMS accidents since 1992 (including one accident after our study period) occurred during night VFR flight in single-engine helicopters flown by a single pilot. Spatial disorientation at night or inadvertent flight into non-VFR weather conditions is thought to have been a major contributor in these accidents.18,19,21 A 2002 review of HEMS safety in the US by the Air Medical Physician Association17 reported that a disproportionate number of accidents occur at night, and during “on scene” transports (primary retrievals). They also noted that more than 85% of weather-related HEMS accidents occurred at night. Our observations appear to be consistent with international experience, and we believe that patient transport by VFR helicopters in inclement weather or at night cannot be supported. One of the major difficulties encountered in this study was that Australia does not have a centralised compulsory reporting system for HEMS flying hours and for the number of patients transported. This makes accurate assessment of HEMS accident rates and patient risk difficult. We recommend establishment of a centralised national database as a means of monitoring HEMS activity and safety. 1 Australian helicopter emergency medical services, 1992–2002 Year Missions Patients Flying hours Accidents 1992 1 278 1 278 1 707 0 1993 1 755 1 755 2 423 1 1994 1 809 1 769 2 882 0 1995 2 213 2 199 3 233 0 1996 3 637 3 609 4 784 0 1997 4 364 4 343 5 567 1 1998 5 838 5 838 7 962 0 1999 6 817 6 526 9 057 0 2000 7 582 7 257 10 347 1 2001 7 303 6 907 10 170 0 2002 7 568 6 982 10 303 0 Total 50 164 48 463 68 435 3 2 Australian helicopter emergency medical services activity, by state, 1992–2002 Missions Patients Flying hours Accidents NSW 21 336 21 336 32 421 0 QLD 16 899 16 795 23 199 3 VIC 9 524 7 829 8 720 0 SA 1 982 2 080 3 164 0 TAS 423 423 931 0 Total 50 164 48 463 68 435 3 3 Comparison of accident rates for different helicopter emergency medical services Helicopter emergency medical service Period Missions Patients transported Flying hours Accident rate per 100 000 flying hours Fatal Total Australia (total) 1992–2002 50 164 48 463 68 435 1.46 4.38 Australia (excluding QLD) 1992–2002 33 265 31 668 45 236 0.00 0.00 QLD government 1992–2002 8 532 8 532 11 212 0.00 0.00 QLD community 1992–2002 8 367 8 263 11 987 8.34 25.03 United States16 1982–1987 Not available 4.7 11.7 Germany16 1982–1987 Not available 4.1 10.9 United States17 1992–2001 Not available 1.69 4.83 4 Summary of HEMS accidents in Australia, 1992–200318-21 VFR = Visual Flight Rules: the helicopter is principally flown and navigated by visual reference to ground features. The pilot must be able to see at least 5 km and maintain 1.5 km horizontal and 1000 feet vertical separation from cloud. This may be reduced in some circumstances for helicopters so that the pilot only has to be able to see 800 m and remain clear of cloud. When flight cannot be conducted under VFR, then Instrument Flight Rules (IFR) apply, with the aircraft principally flown and navigated by reference to the aircraft instruments and avionics. Not all aircraft are equipped for IFR. Acknowledgements We wish to thank the following for their support and for providing data: Mr Rob Johnson, Director of Aviation Services, Queensland Department of Emergency Services; Mr Jim Campbell, Chief Pilot, Sunshine Coast Helicopter Rescue Service; Dr Ron Manning, Director Medical Retrieval Unit, Ambulance Service of New South Wales; NT Aerial Service; Mr Keith Young, Operations Manager, Air Ambulance Victoria; Ms Jean Henley, Manager, The Tasmanian Air Rescue Trust; Ms Roslyn Clermont, Corporate Information Officer, South Australian Ambulance Service; Mr George Nadal, Australian Transport Safety Bureau; Mr John Streeter, Bureau of Transport and Regional Economics, Department of Transport and Regional Services. Special thanks to Ms Alycia Snell for her assistance with collation and formatting. References 1. Bartolacci RA, Munford BJ, Lee A, McDougall PA. Air medical scene response to blunt trauma: effect on early survival. Med J Aust 1998; 169: 612-616. <eMJA full text> <PubMed> 2. Jacobs LM, Gabram SG, Szrajnkrycer MD, et al. Helicopter air medical transport: ten-year outcomes for trauma patients in a New England program. Connecticut Med 1999; 63: 677-682. 3. Baxt WG, Moody P. The impact of a Rotorcraft aeromedical emergency care service on trauma mortality. JAMA 1983; 249: 3047-3051. <PubMed> 4. Lerner EB, Billittier AJ, Dorn JM, Wu YWB. Is total out-of-hospital time a significant predictor of trauma patient mortality? Acad Emerg Med 2003; 10: 949-954. <PubMed> 5. Thomas SH, Cheema F, Wedel SK, Thomson D. Trauma helicopter emergency medical services transport: annotated review of selected outcomes-related literature. Prehosp Emerg Care 2002; 6: 359-371. <PubMed> 6. Hotvedt R, Kristiansen IS, Forde OH, et al. Which groups of patients benefit from helicopter evacuations? Lancet 1996; 347: 1362-1366. <PubMed> 7. Arfken CL, Shapiro MJ, Bessey PQ, Littenberg B. Effectiveness of helicopter versus ground ambulance services for interfacility transport. J Trauma 1998; 45: 785-790. <PubMed> 8. Kurola J, Wangel M, Uusaro A, Ruokonen E. Paramedic helicopter emergency service in rural Finland — do benefits justify the cost? Acta Anaesthesiol Scand 2002; 46: 779-784. <PubMed> 9. Snooks HA, Nicholl JP, Brazier JE, Lees-Mlanga S. The costs and benefits of helicopter emergency ambulance services in England and Wales. J Public Health Med 1996; 18: 67-77. <PubMed> 10. Arfken CL, Shapiro MJ, Bessey PQ, Littenberg B. Effectiveness of helicopter versus ground ambulance services for interfacility transport. J Trauma 1998; 45: 785-790. <PubMed> 11. SAR, EMS and police directory. Heli-News Australasia 2001; December: 40-41. 12. National Transportation Safety Board. Safety study: commercial emergency medical service helicopter operations. NTSB/SS-88/01. Washington, DC: NTSB, 1988. 13. Harris JS. US Hospital-based EMS helicopter accident rate declines over the most recent seven year period. Helicopter Safety 1994; 20(4): 1-7. 14. Collett HM. Accident trends for air medical helicopters. Hospital Aviation 1989; 8(2): 6-11. <PubMed> 15. De Lorenzo RA, Freid RL, Villarin AR. Army aeromedical crash rates. Mil Med 1999; 164: 116-118. <PubMed> 16. Rhee KJ, Holmes EM, Moecke HP, Thomas FO. A comparison of emergency medical helicopter accident rates in the United States and the Federal Republic of Germany. Aviat Space Environ Med 1990; 61: 750-752. <PubMed> 17. Blumen IJ, UCAN Safety Committee, editors. Air medical physician handbook, November 2002 supplement. Salt Lake City, Utah: Air Medical Physician Association, 2002. 18. Air Safety Occurrence Report 200003130. Australian Transport Safety Bureau, 16 May 2002. Available at: www.atsb.gov.au/aviation/occurs/ (accessed Oct 2004). 19. Air Safety Occurrence Report 199301330. Australian Transport Safety Bureau, 9 Mar 1994. 20. Air Safety Occurrence Report 199701421. Australian Transport Safety Bureau, 8 Sep 1998. Available at: www.atsb.gov.au/aviation/occurs/ (accessed Oct 2004). 21. Air Safety Occurrence Report 200304282. Australian Transport Safety Bureau, 10 Jun 2004. Available at: www.atsb.gov.au/aviation/occurs/ (accessed Oct 2004). 22. Cunningham P, Rutledge R, Baker CC, Clancy TV. A comparison of the association of helicopter and ground ambulance transport with the outcome of injury in trauma patients. J Trauma 1997; 43: 940-946. <PubMed> (Received 7 Jun 2004, accepted 11 Oct 2004) Department of Emergency Medicine, Royal Adelaide Hospital, Adelaide, SA. Jim Holland, MB BS, Emergency Medicine Registrar. Department of Emergency Medicine, Townsville Hospital, Townsville, QLD. David G Cooksley, MB ChB, FACEM, Emergency Physician. Correspondence: Dr D G Cooksley, Department of Emergency Medicine, Townsville Hospital, PO Box 670, Townsville, QLD 4810. dgcooksleyATausdoctors.net AntiSpam note: To avoid spam, authors' email addresses are written with AT in place of the usual symbol, and we have removed "mail to" links. Replace AT with the correct symbol to get a valid address. ©The Medical Journal of Australia 2005 www.mja.com.au Print ISSN: 0025-729X Online ISSN: 1326-5377 ........................................... Editorial : Safety of emergency medical service helicopters Alan A Garner, Deanne M Keetelaar and Jeff Konemann MJA 2005; 182 (1): 12-13 Robust safety specifications and funding arrangements are needed A recent review of the safety of helicopter emergency medical services (HEMS) in the United States found that the risk of death for a HEMS crewmember (per hour engaged in the activity) was similar to that of rock climbers and skydivers.1 The study on the accident and fatality rate of HEMS by Holland and Cooksley (page 17) in this issue of the Journal2 is a timely reminder of the risks faced by HEMS crew in Australia. . . . at least one Australian state government is yet to conduct any independent audits of its contracted HEMS operators . . . Aviation safety, like patient safety, is a complex interaction of systems, human factors and technology. Many of the lessons learned in aviation in improving safety and management of risk, such as incident reporting, crew resource management and simulator training, have crossed over into medical practice. The underlying issues affecting safety are similar, and are frequently unrelated to operator error. Investigation of major incidents and accidents worldwide, in industries such as transport, mining, and indeed health, has revealed many common contributing factors identified as “latent conditions”, or failures of the system.3 These include the lack of a positive safety culture through poor governance, limited resources or misallocation of resources. Blame for accidents often lies with operator error, or active failures (slips, lapses and mistakes — errors at the level of the frontline operator), but it is the mitigation of latent failures that is likely to have the biggest impact on safety. HEMS in Australia operate in a risky environment for flight crew, medical crew and patients alike, for several reasons. First, HEMS in Australia are generally required to fulfill multiple roles, performing critical care interhospital transfer, land-on-scene response, hoist operations and search and rescue (SAR). In North America and Europe, there is generally a distinction between hoist and SAR operators and those who undertake interhospital transfers and land-on-scene response. Second, Australian HEMS operations are further complicated by the vast distances and the predominantly hot conditions, which challenge both aircraft and crew performance. All incidents with injuries or fatalities reported by Holland and Cooksley2 were flights conducted in helicopters without sufficient instrumentation for flight in cloud. Under the current regulatory requirements, flight in such aircraft over water or in rural areas at night is acceptable but is not viewed as best practice. Aircraft not equipped to fly in cloud have much lower acquisition costs than aircraft that are so equipped. Crew training and experience levels are also substantially less. Such aircraft continue to be used for HEMS in Australia, operating with minimal safety margins, as a result of inadequate funding arrangements. In Australia, the Civil Aviation Safety Authority (CASA) certifies aircraft operators to provide specified levels of service. However, CASA certification does not necessarily mean a safe operator, any more than accreditation by the Australian Council on Health Care Standards means a safe hospital. Furthermore, the supervision provided by CASA varies with the category of operation. HEMS is situated at the lower end of the oversight spectrum by virtue of the category of operations in which CASA has placed it, resulting in a level of scrutiny that, given the complexity and risk involved, is lower than perhaps required. Recategorisation of HEMS into a higher category requiring higher standards of compliance, and hence scrutiny by CASA, is probably appropriate. However, effecting regulatory change is a slow process. Given the low level of regulator scrutiny in some categories of aviation operations, the industry has recognized a need to enforce its own standards by commissioning aviation safety experts to conduct independent safety audits. For example, in high-risk areas, such as the off-shore oil industry, oil companies conduct independent safety audits of contracted helicopter operators as frequently as every couple of months. Although HEMS carry greater risk than off-shore oil work, at least one Australian state government is yet to conduct any independent audits of its contracted HEMS operators, despite this being a requirement of contract. Recent accidents in Australia2 have highlighted latent factors, such as equipment and crewing issues. However, to operate the equipment specified by either regulations or contracts, operators will only put in place systems they can afford. Maintaining the high standards mandated by this complex operating environment requires that health systems work in partnership with HEMS providers to ensure robust contract and auditing processes. This does not come without cost, and adequate funding of HEMS needs to be accepted and achieved. Cost cutting to ensure financial survival compromises the safety systems that HEMS operators endeavor to put in place. These are designed to mitigate error, and include hazard and incident reporting, training and education, audit programs, and safety officer appointment. Against this background, a group of community HEMS providers in NSW and Queensland have commissioned, at their own expense, the development of a safety and integrated risk-management framework for HEMS. This is being facilitated by a specialized aviation risk-management company, which has been responsible for the development of similar programs for the Royal Australian Air Force, commercial airlines, airports and other aviation organizations. This program is a collaborative effort by HEMS operators to exceed regulatory compliance and lead the way for best practice. The program has subsequently expanded to a trans-Tasman initiative, with a number of New Zealand operators joining the consortium. The framework will be formally launched in February 2005. Robust safety specifications and funding arrangements are essential to ensure that HEMS operations in Australia are performed at a more appropriate level. 1. Blumen I, and the UCAN Safety Committee. A safety review of risk assessment in air medical transport. Supplement to the Air Medical Physician Handbook, November 2002. Salt Lake City, Utah: Air Medical Physician Association, 2002. 2. Holland J, Cooksley DG. Safety of helicopter aeromedical transport in Australia: a retrospective study. Med J Aust 2005; 182: 17-19. 3. Reason J. Human error: models and management. BMJ 2000; 320: 768-770. <PubMed> (Received 11 Oct 2004, accepted 4 Nov 2004) NRMA CareFlight/NSW Medical Retrieval Service, Sydney, NSW. Alan A Garner, FACEM, MSc, Medical Chairman; Jeff Konemann, CFS, Training and Safety Manager. Aerosafe Risk Management, Sydney, NSW. Deanne M Keetelaar, Risk Adviser. Correspondence: Dr Alan A Garner, NRMA CareFlight/NSW Medical Retrieval Service, PO Box 159, Westmead, NSW 2145. alangATcareflight.org AntiSpam note: To avoid spam, authors' email addresses are written with AT in place of the usual symbol, and we have removed "mail to" links. Replace AT with the correct symbol to get a valid address. --- SMU-L Bonne annee a tous!
