Kristin Graham, left, comforts her son, Gatlan, during a visit to the doctor Dec. 30 in Houston. For many who depend on home medical equipment, a power outage goes beyond inconvenience — it could be deadly. As more critically ill people are moving out of nursing homes and into home care, emergency officials have had to adapt to large numbers of power-dependent patients.

WASHINGTON — For many of the growing millions who depend on home medical equipment, a power outage goes way beyond the inconvenience most of us feel. It could be deadly.

It's an issue that snuck up on emergency officials as better medical treatments over the past decade have helped more critically ill people not only survive but move out of nursing homes.

The Associated Press found emergency planners around the country struggling to find new ways to identify people at risk before the lights go out, to ensure they will have the aid they need to survive small outages or big ones.

How serious is the problem?

When ice downed electric lines in Epping, N.H., last month, police found 60-year-old Richard Lapoint dead, hooked to his powerless oxygen machine. The town's rescue workers hadn't known he was power-dependent.

A generator and stack of batteries couldn't keep up with Gatlan Graham's ventilator and other life-supporting equipment when Hurricane Ike knocked out power to his Houston home for 14 days in September. The family fled in search of electricity, spending more than $1,500 to keep the 17-year-old alive.

Utilities in every state operate "medical priority lists" designed to track who depends on power for life. But an AP survey found huge state-to-state variations that suggest only a fraction of patients know they could sign up. Illinois' biggest utilities together report 10,000 patients on critical-care lists, for example. Neighboring Indiana's biggest list carries just 2,000 names.

Even if patients did sign up, in large outages companies don't have the ability to restore power to one home before another down the street. The lists may offer false hope.

"The power companies don't get on the phone and dial 911 for their customers," said Dr. David Prezant, chief medical officer for the New York City Fire Department, who is pushing for medical registries of the power-dependent. "When there's a blackout, citywide, nationwide, we are really unprepared with any structured database, knowledge of who these people are and where they are."

Registries are starting to form — from Benton County, Ark., to North Dakota, which begins a statewide Web-based registry this month.

To help people prepare, the Food and Drug Administration this spring plans to issue the first checklist for device recipients to receive when leaving the hospital.

Emergency workers feel the clock ticking.

"It's incumbent upon us over the next 4Z\x months, before we get into hurricane season again, to have a better plan than we had going into Ike," said Terry Moore, Houston's deputy emergency management coordinator.

"This is a huge vulnerability," added Dr. Lewis Rubinson of the University of Washington, who advises the government on disaster preparations and separately is preparing guidelines for emergency oxygen supplies. "This is something that patients should demand."

It's a growing population. Roughly 2 million people use home oxygen machines, mostly "concentrators" that make oxygen on the spot as long as electricity flows. Just a few years ago, oxygen-gas tanks that don't require home electricity were the norm.Millions more use other at-home equipment: dialysis machines, nebulizers, IV and nutrition pumps, CPAP breathing masks. But power failures bring the most immediate risk for users of ventilators, heart pumps and oxygen.Ventilators and heart pumps have internal batteries that last 45 minutes to a few hours, time to put on longer-lasting batteries or get to help. Some portable oxygen concentrators can run on batteries for three hours or four hours or be plugged into a car adapter, but patients typically depend on oxygen suppliers to deliver old-fashioned tanks of the gas for emergency use."I thought I was prepared," said Houston's Kristin Graham. Before Hurricane Ike, she readied a generator, gasoline and rechargeable batteries that could run son Gatlan's ventilator for six hours to nine hours on a charge, and his oxygen machine for another few hours.But the outage lasted so long, Graham said: "We couldn't afford to buy the highest-powered generator on the market. You can't run that generator 24 hours. You run it a couple of hours, you let it rest a couple of hours. I could never get all the batteries recharged."Graham signed up for her utility's priority list and Houston's 211 emergency service, but said no one checked if she needed aid. Ultimately she loaded Gatlan, his medical equipment and his 4- and 8-year-old siblings into the family van and checked into a hotel room, first in a less hard-hit Houston area and later in cheaper Austin, to get electricity."I don't know what people would do if they didn't have a way to get out on their own," she said. "No one cared this time if you were on a critical list. They couldn't. It was too broad."

The 2003 Northeast blackout, the nation's largest power failure, was a wake-up call for New York City's Prezant. In a study published in the journal Critical Care Medicine, Prezant tracked citywide 911 calls plus emergency room visits at his own large hospital, Montefiore Medical Center, during the nearly 29-hour blackout.The falls and heart attacks doctors had expected didn't materialize. But paramedics and the ER had a surge in patients with at-home oxygen, ventilators and other respiratory equipment who needed help or feared they soon would. Moreover, frail patients often were admitted to the hospital because doctors couldn't be sure a power failure was the only problem, a huge expense fraught with the risk of medical errors, said Prezant, a lung specialist.Whatever a family's back-up plan, Rubinson and Prezant stress that local emergency officials must know how many power-dependent patients they might have to rescue, and getting utilities and home-care companies to share customer lists is a good start.Even the federal government was surprised by the demand during Hurricane Gustav, when nearly 1,400 people were housed in special medical shelters in Louisiana and Texas, 20 percent to 40 percent of whom required powered medical equipment. When generators failed in Baton Rouge shelters, an oxygen supplier hired to refill patients' oxygen tanks couldn't keep up with the unanticipated need."We had some nervous wringing of hands as some of the oxygen tanks started going down to low levels," said Dr. Allen Dobbs, chief medical officer of the National Disaster Medical System — though enough eventually was found. "We have to have reliable contingency back-up plans for these folks."