Meanwhile, some key state officials are questioning the criteria for flying patients on Maryland State Police helicopters.
NTSB spokesman Keith Holloway said investigators should conclude their field work as early as today, and a preliminary report should be posted on the board's Web site next week.
"It will not determine causes, but will merely relay the facts as we know them," he said. "We are not at a point we can determine a cause. It can take 12 to 18 months to determine a cause."
Helicopters are dangerous machines that should be used only when medically essential, said Del. Dan Morhaim, a career emergency medicine physician and co-chairman of the Joint Committee on Health Care Delivery and Financing.
Mr. Morhaim, along with a handful of other lawmakers, has long said helicopters are used too often for transporting patients with minor injuries.
"The death rate for air medical crews is 15 times higher than for all other workers, and three times higher than for miners," Mr. Morhaim, D-Baltimore, said pointing to a report presented to his office in February by the faculty at the John Hopkins School of Public Health.
"That doesn't mean it (medevac flights) shouldn't be done, but their use should be as judicious as possible," he said.
Questions about the overuse of helicopters began surfacing earlier this year.
Mr. Morhaim said after a story ran in <i>The Capital </i>describing the problem, more lawmakers began questioning the use of medevac flights.
He said the questions heated up following the release of a state audit in
August that reported state police run a sub-standard aircraft maintenance program and fail to keep adequate records.
Between 50 percent and 75 percent of the roughly 5,000 patients the Maryland State Police transport by air each year have only minor injuries, Mr. Morhaim said. A doctor who helped develop the Maryland trauma system said the shock trauma center and state police helicopters were designed to be overused as a way to generate funds for the medical system.
Dr. Clayton H. Shatney worked with the center's founder, Dr. R Adams Cowley, and taught medicine at the University of Maryland between 1979 and 1982.
Speaking last night from his home in California, Dr. Shatney said he hadn't heard of the Maryland helicopter crash because he has been submerged in a four-day medical conference in Hawaii.
The subject of the conference? Overuse of shock trauma centers and medevac helicopters.
"We are trying for 100 percent (standard of care), which is not possible," he said. "The gross over-triage we are doing is a long-standing, nationwide problem that nobody wants to tackle." In some cases, the patients don't show symptoms of injury, but the "mechanism of injury" requires field paramedics to send patients to trauma centers aboard helicopters.
Examples of "mechanism of injury" cases that qualify patients for treatment at a trauma center include when a patient falls three times his height or is thrown from a bicycle at any speed. Under state regulation, if the patient is more than 30 minutes' travel time by land from a trauma center, the paramedic is to call for a helicopter.
"The number of (actual injuries) in 'mechanism of injury' cases is miniscule, it is not cost-effective," Dr. Shatney said.
Early last month, Mr. Morhaim's joint committee conducted a hearing on the Emergency Medical System, and followed up by sending questions to Dr. Robert Bass, executive director of the Maryland Institute for Emergency Medical Services Systems.
"We don't want to take patients to a trauma center by helicopter who don't need it," he said.
Dr. Bass said he has "enlisted" help from trauma experts at Johns Hopkins University in reviewing current standards.
"There is not always an exterior manifestation of injuries, but there could be a lacerated liver, a torn bowel or a ruptured spleen," he said.
The two patients who were being transported when the crash occurred late Saturday were Priority 2, Dr. Bass said. That means they had, according to state standards, a "less serious condition, requiring emergency medical attention, but not immediately endangering the patient's life."
"We have known about this problem for 15 years," he said, "but it takes three years to get something into the medical literature and 30 years to get it out."

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