Royal Flying Doctor Service Essential Aspects of Aeromedical Retrieval
Modes Of Transport
Session Objectives Consider the requirements for the ideal mode of transport Discuss the advantages and disadvantages of each mode of transport Introduce the evidence base for transport selection Introduce the relevant safety issues
The Gold Standard Easily available Safe Cost effective Spacious Easy to load / unload Access to the whole patient Fast Comfortable Quiet Door to door Easy to divert Not weather dependent No physiological consequences Adequate power supply Large centre of gravity Replicates your Resus bay DOES NOT EXIST
3 Principal Modalities Ground Ambulance ( Road ) Rotary Wing Fixed Wing
Choice of Transport Clinical scenario Diagnosis Stability Anticipated complications Urgency for definitive care Current level of care Patient numbers Availability Weather and traffic conditions Local geography Distance Terrain Accessibility Safety Cost
Ground Ambulance
Ground Ambulance Advantages Easily available Door to door Easy to load / unload Easy to divert Relatively roomy Familiarity Relatively low cost Well established infrastructure Few weather constraints
Ground Ambulance Disadvantages Lengthy transit times over long distances or difficult terrain Subject to traffic conditions Rough ride Firm suspension High centre of gravity Motion sickness
Rotary Wing
Rotary Wing Advantages Rapid transport times over moderate distances Accessibility Maneuverability Versatility Pretty much go anywhere
Rotary Wing Disadvantages Requires adequate hospital based landing sites Loading problems Limited space and patient access issues Weather and fuel constraints eg high temps in QLD limit lifting capacity Non pressurised Noise and vibration Not always easy to maintain thermal integrity Incident light High staff training requirements Expensive
Fixed Wing
Fixed Wing Advantages Rapid transport over long distances Pressurisation ( not always ) Higher operating ceiling Ability to fly around bad weather Relatively large cabin space ( usually ) Quieter than RW
Fixed Wing Disadvantages Need an airstrip to take off / land Multiple patient transfers Substantial take off / landing forces
Distance GA GA or RW RW RW or FW FW
ACEM Previously suggested that patients less than 30/60 by road are unlikely to benefit from helicopter transportation Australasian College for Emergency Medicine and Australian and New Zealand College of Anaesthetists. Policy on minimum standards for transport of the critically ill. Emerg Med. 1993;5:245 324.
Thomas, Wisham et al FW vs RW at ranges of 101 150 radial miles FW 509 vs RW 104 No significant difference in time to hospital No differences in ISS. Age, LOS, mortality, discharge disability score for trauma patient RW costs 400 x those of FW Thomas F, Wisham J, Clemmer TP, et al. Outcome, transport times, and costs of patients evacuated by helicopter versus fixed-wing aircraft. West J Med. 1990;153:40-43.
Diaz, Hendey et al Ground ambulance always faster at distances of less than 16 km At greater distances HEMS faster if simultaneously dispatched In the real world ground ambulance likely to be faster up to 70 km Diaz MA, Hendey GW, Bivins HG. When is the helicopter faster? A comparison of helicopter and ground ambulance transport times. J Trauma. 2005;58:148.
Trying to make sense of it all? GA < 16 km GA or RW 16 160 km RW > 100 km RW or FW 160 240 km FW > 240 km Guidelines at best!!
A sobering thought Fatal Crashes per million flight hours 20 18 16 14 12 12 12 10 8 6 6 4 2 1 0 19 Airline Commuter Ground Ambulance All Helicopters Medical Helicopters A Safety Review and Risk assessment in Air Medical Transport AMPA 2002
But that was 2002!! Year Accidents Fatalities 2003 19 7 2004 13 18 2005 15 11 2006 13 5 2007 12 7 2008 13 29 National Transport Safety Board Review on HEMS related Actvities
Australia Australian HEMS Data 1992-2002 Year Flying Hours Accidents 1992 1707 0 1993 2423 1 1994 2882 0 1995 3233 0 1996 4784 0 1997 5567 1 1998 7962 0 1999 9057 0 2000 10347 0 2001 10170 1 2002 10303 0 Totals 68435 3 Accidents: 4.38 / 100 000 flying hrs Fatalities: 1.46 / 100 000 flying hrs 14.6 / million flying hrs Holland J, Cooksley DG. Safety of helicopter aeromedical transport in Australia: a retrospective study. Med J Aust 2005; 182: 17-19.
Twin vs Single RW Analogous to Crystalloid vs Colloid No definitive proven safety benefits Twins generally Perceived to be safer More powerful Cost more to buy initially Have ~ 30% more operating costs Increasingly regulated for AME work
Do you really understand your choices? Cheapest to buy may not be cheapest to run Fastest may not mean the best range Fastest does not mean safest Shortest flight time does not mean shortest time to definitive care Safety benefits may only apply if flown within strict weight limits and flight profiles VFR vs IFR? Turboprop vs jet? Single engine vs twin?
Summary Individualise the mode of transport to the patient s clinical need Consider Local knowledge especially geographical Actual or potential need for time critical interventions Availability of and impact on existing resources Risks vs benefits Safety Understand your transport choice, its limitations and its capabilities
FW vs RW No airplane will be good until it can go straight up and down Thomas Edison Helicopters can't fly; they're just so ugly the earth repels them Anon