No one knows whether an avian flu virus that is racing around the world might mutate into a strain that could cause a human pandemic, or whether such a pandemic would cause widespread illness in the United States. But if it did, public health experts and officials agree on one thing: The nation's hospitals would not have enough ventilators, the machines that pump oxygen into sick patients' lungs.
Right now, there are 105,000 ventilators, and even during a regular flu season, about 100,000 are in use. In a worst-case human pandemic, according to the national preparedness plan issued by President Bush in November, the country would need as many as 742,500.
To some experts, the ventilator shortage is the most glaring example of the country's lack of readiness for a pandemic.
"This is a life-or-death issue, and it reflects everything else that's wrong about our pandemic planning," said Dr. Irwin Redlener, director of the National Center for Disaster Preparedness at Columbia University. "The government puts out a 400-page plan, but we don't have any ventilators, and there isn't much chance we're going to get them."
A typical hospital ventilator costs $30,000, and hospitals, operating on thin profit margins, say they cannot afford to buy and store hundreds of units that might never be used. Cheaper alternatives can be deployed in a crisis, but doctors say they are grossly inadequate to deal with a flu pandemic.
Congress authorized only $3.8 billion of the $7.1 billion that Bush requested for flu preparedness, and nearly 90 percent of it is earmarked for vaccines and the antiviral drug Tamiflu. Buying enough ventilators for a flu outbreak like that of 1918 would cost $18 billion.
"We only have a certain amount of money to spend on preparedness," said Thomas W. Skinner, a spokesman for the U.S. Centers for Disease Control and Prevention in Atlanta. "We can't invest strictly in respirators."
The federal preparedness plan leaves preparations for medical care up to state and city health officials, but the only government agency that amasses ventilators is the Strategic National Stockpile, created in 1999 by the disease centers to store medicine and equipment for use in a terrorist attack or a disaster. But the agency has only 4,000 to 5,000 ventilators, according to a federal official who spoke on the condition of anonymity because of a dispute between government health and security agencies about whether the size of the stockpile ought to be kept secret.
There is also a shortage of trained personnel, said Dr. Michael T. Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota.
"Ask any respiratory therapist - you have to adjust the gases, the pressures," he said. "We don't have enough trained people to maintain them."
In a recent emergency drill, said Dr. John L. Hick, a professor of emergency medicine at the Mayo Medical School in Minnesota, the 27 hospitals in his area could come up with only 16 extra ventilators when faced with a hypothetical outbreak of 400 cases of pneumonic plague.
"In a pinch," Hick said, "you can hand-bag people," a procedure in which a fat plastic bellows is squeezed to push air into the lungs. "But in a pandemic, you're stuck."
Hick wrote a recent paper for The Journal of Academic Emergency Medicine suggesting guidelines to determine in a crisis which patients should be taken off ventilators and allowed to die.
In a national emergency, he said, "it will come down to some really thin cuts on a scoring system."
"Families are going to be told, `We have to take your loved one off the ventilator even though, if we could keep him on it for a week, he might be fine,'" he went on. "How do you think that's going to go over?"
Representatives of three of the country's largest hospital chains, HCA, Tenet Healthcare and Triad Hospitals, said they were aware of the potential shortage. "We're considering the feasibility of acquiring additional ventilators, but I can't say we're even close to making that decision," said Jeff Prescott, a spokesman for HCA.
Steven Campanini, a spokesman for Tenet, said the company had looked at seven models from $40 to $30,000 but had not made any extra purchases. "There are split camps about whether or not bird flu will mutate," Campanini said. "But we recognize the threat, and, should the need arise, we'll work with state and local officials to meet it."
Draeger Medical, a German company that is the world's largest maker of hospital ventilators, can double its assembly line capacity in a week, said Mandy Hartman, a vice president for marketing. In a year, that would add "more than 10,000" ventilators to the world supply, said Hartman, who declined to be more specific.