The statistics might be a mere curiosity, he said, if not for the risk that helicopter transport poses. Ground ambulances crash too, but rarely with such deadly consequences.
"It clearly needs to be re-evaluated," Bledsoe said "Somewhere along the line, there's been a paralysis of intellect where helicopters are concerned."
Maryland officials are re-evaluating, but they say the unpredictable and potentially deadly nature of trauma care makes easy answers elusive.
Maryland guidelines call for flights to be operated in cases in which a trauma center is longer than a 30-minute drive away. That would seem to preclude almost every accident inside the Beltway, but medics also consider traffic congestion, which sometimes means flying just a few miles.
"You can err on the side of patients, and perhaps fly too many to a trauma center, or you can err on the side of under-triage and potentially lose some patients," Bass said. "There is no perfect way."
The two patients involved in last week's crash in Maryland, one of whom survived, were both alert and talking when they boarded the helicopter, but had been selected to fly the 30-mile trip to the nearest trauma center based on the nature of the car accident that caused their injuries.
The "mechanism" of injury - in their case a 12- to 18-inch dent into their vehicle's passenger compartment - is used throughout the country to predict medical problems that are not otherwise apparent, though recent scientific studies suggest that the technique is inaccurate as much as 80 percent of the time.
Maryland's emergency medical officials say they are re-evaluating their reliance on mechanism of injury to determine the method of transport. McSwain and others said they should also consider having paramedics or emergency technicians quickly transport such patients to a nearby community hospital, where doctors could use X-rays or ultrasound to determine whether they need to go to a trauma center.
Last week's car accident in Waldorf occurred about 10 miles from a community hospital in LaPlata where doctors could conceivably have assessed whether the victims needed to fly.
Advocates of helicopter transport see that as an unnecessary delay in treatment and say it ignores one of a helicopter's greatest assets - its on-board paramedic. While ground ambulances are often staffed by technicians trained in basic life support techniques, helicopters typically carry paramedics trained in advance treatments such as resuscitation and airway intubation. And they are often among the system's most experienced responders, because of the volume of complex cases they see.
"You have to look at it as bringing Shock Trauma to the patient," said Dr. Kevin Hutton, an emergency medicine physician and chairman of the Foundation for Air-Medical Research and Education in Virginia. "When you call a helicopter, you're asking for the highest level of care available at the scene."
In that context, even short flights make sense, Hutton said. He recalled a patient he once treated who had to be delicately removed from a piece of machinery after an industrial accident. Paramedics intubated and stabilized him while a helicopter waited outside. The trauma center was close enough for an ambulance - less than two miles away - but with a helicopter the patient got there within minutes and had already received advanced care.
"Is it better to front-load all of that at the risk of determining later that it wasn't necessary? Or is it better to miss a few and have them die?" he asked. "I think that's a very effective and appropriate use of helicopters."
Yet critics question whether the supposed advantage of advanced on-scene treatment is any more valid than for air transport over ground transport.
A 1996 study in Los Angeles of almost 6,000 patients found that victims of severe trauma fared better when they got a ride to the hospital in a friend's car than if they waited for an ambulance or helicopter. A study in Canada found that the more advanced the on-scene care was, the less likely a patient was to survive - even when physicians responded to accidents.
Mattox said such studies reveal that the biggest need for trauma patients is to be treated at a hospital, not at the scene. And while helicopters travel faster than ground vehicles, the time spent warming up engines and preparing patients for transport can minimize or eliminate the speed advantage. The London study found helicopter patients were treated by paramedics 25 minutes faster, on average, but typically arrived at a hospital 10 to 20 minutes later than patients in ambulances.
"When you see these helicopters on television loading a patient, what do you almost always see in the background? A ground ambulance," said Mattox, who is among the nation's leading researchers into the practice of using intravenous fluid to treat trauma patients. "In many cases, if they had just loaded the patient and gotten to the closest appropriate hospital, instead of waiting for the helicopter, the patient would be better off."
"If we could show a survival difference, or even a morbidity difference, I would be the first to say, 'Let's do it,'" Mattox added. "But we can't."
Bledsoe said he often holds up Maryland's medevac system - state-financed and -maintained, well integrated into the region's emergency response system - as one of the best. In other states, where helicopters are typically privately owned, commercial interests can encourage operators to take unnecessary risks and transport patients to inappropriate facilities. Still, he considers Maryland's helicopter fleet - including 6 commercial aircraft and 12 operated by the state police - to be excessive.
"Whenever people ask me which system is the model, I always say Maryland's. I think conceptually it's very good," Bledsoe said.
"You probably only need two or three helicopters, though. They're easy to justify out in Western Maryland or in other rural areas, but why are they flying people around Baltimore and Washington?"
Helicopter transports have dropped off slightly in the past year, perhaps because emergency medical crews are adhering closely to the state's triage guidelines on when to call for air transport.
But any acceptable system will fly patients who, in hindsight, did not need to fly helicopters, he said. Medics err on the side of caring for a patient. And that won't change.
"I also believe it's not just about cost, and not just about safety," Bass said, "but also the thinking that when you really need that helicopter, you want it to be available."