Re: Princess Leia had a heart attack!
The cabin is pressurized, you moron. If you are thousands of feet up in the air in a plane and gasping for oxygen, I urge you to inform the flight crew that the cabin has depressurized, or else u will die, ok?
I know what I felt & when I was flying I had breathing difficulties. So I can't accept the argument that the cabin is pressurised. On checking I found out that there is a heath risk if you are suffering from health problems e.g. heart problems.
So if you are older & having health problems you should take note that you might die in the air
http://usatoday30.usatoday.com/news/nation/2001-03-05-oxygen.htm
Do passengers get enough oxygen?
By Robert Davis, USA TODAY
As the number of reported heart attacks, faintings and other medical emergencies aboard airlines continues to soar, the government is considering changing the way cabins are pressurized to provide more oxygen to passengers. The Federal Aviation Administration and scientists across the industry are reevaluating a standard that was set decades ago and based on studies of healthy servicemen in altitude chambers. The modern airline cabin looks very different, as aging baby boomers — many with health problems that can worsen suddenly and sometimes fatally — fly farther and longer than ever before.
There is plenty of oxygen in the air inside airline cabins. But because the barometric pressure is lower — equivalent to standing on an 8,000-foot mountain — not as much oxygen reaches the bloodstream to be carried to vital organs. Much of the focus on cabin air quality has been on the spread of viruses such as the common cold. But a new focus is emerging as scientists and doctors learn more about the threat that affects every airline passenger: hypoxia, the term for too little oxygen.
This lack of oxygen usually causes little more than a headache and a feeling of fatigue in the average healthy flier. But passengers who have an underlying breathing, heart or circulatory problem — even one they don't yet know exists — can suffer serious medical emergencies when the oxygen level drops. Heart attacks are among the more serious problems that hypoxia could cause during airline flights.
"People are traveling to all ends of the Earth and very little attention has been given to the impact and the insult on the human body during flight," says Marian B. Sides, a vice president of the Aerospace Medical Association. As a military researcher, she has studied the drop in oxygen levels at cruising altitudes.
"Ten to 15 years ago, we were concerned about smoking on airlines. Now this is the next level of concern," Sides says. "Going on an aircraft does in fact compromise one's rate of oxygenation. The oxygen deficits are significant."
While aviation experts reconsider — sometimes skeptically — the cabin pressure standards, the National Academy of Sciences has appointed a panel of medical experts to determine the exact health risks of breathing cabin air. The effort, which is expected to be completed this year, comes as the number of reported medical emergencies aboard airliners is increasing.
The FAA does not track the number of medical emergencies in the air, but MedAire, a Phoenix-based company that connects doctors with flight crews and ill passengers in flight, says medical emergencies are at an all-time high. In the mid-1980s, there were about 10 deaths each year on U.S. airliners.
Now, industry officials estimate, as many as 100 people a year die because of medical problems during flights. MedAire hears about many of them: The company helps 35 airlines around the world and took 8,500 medical calls last year.
Aviation experts say in-depth studies would be needed to determine if the hypoxia at cruise altitude is to blame for the medical emergencies. But doctors atMedAire are suspicious. They say that 21% of the calls they get are for passengers who pass out. Heart and breathing problems accounted for 12% and 11%, respectively.
"The issue of hypoxia is really significant for people with heart or lung disease, and no one knows it," says Brent Blue, a doctor and pilot who sells oxygen-measuring devices.
A drop in oxygen
Here's why the body begins losing oxygen within minutes at cruising altitudes:
As the plane soars, extremely hot air is drawn from the jet's engines, cooled and piped into the cabin. This constant flow of very dry air keeps a life-sustaining pressure in the cabin. But because the plane is designed to be as lightweight as possible, it can only withstand so much pressure. The thin aluminum shell of most jets expands like a balloon — as much as an inch — as the pressure inside increases and the outside pressure decreases at high altitudes.
There is just as much oxygen in the cabin air at cruising altitude as on the ground, but because the atmospheric pressure is lower than at sea level, it is more difficult for the body to absorb the vital gas. With less pressure, fewer oxygen molecules cross the membranes in the lungs and reach the bloodstream.
The result is a significant drop in the amount of oxygen in the blood — anywhere from 5% to 20% depending on the person, the plane and the length of the flight.
With less oxygen in the bloodstream, the vital organs soon get deprived.
The reduced oxygen supply to the brain is why some suffer headaches while in flight, one of the symptoms of hypoxia. When oxygen levels fall in the brain, the heart tries to compensate by beating harder and faster. Another symptom of hypoxia is fatigue.
But doctors say the body's efforts to compensate can hurt people who fly with underlying medical conditions.
"Many papers report that the rate of in-flight medical emergencies is higher in cases with cardiovascular or cerebrovascular disorders," says Makoto Matsumura, of the Heart Institute at Saitama Medical School in Japan, who presented new details about the issue at last year's American Heart Association meeting. "The hypoxia is related to the cabin environment. Therefore, it is important to draw attention to the aged and the patients with hypertension who potentially have a vascular disorder."
Joan Sullivan Garrett, who runs MedAire, suspects that many of their medical emergencies are from passengers whose bodies are already weakened by diseases struggling to compensate for a shortage of oxygen.
"In a lot of these, the impetus is some sort of hypoxia," she says. "When you step back and look at the average traveler, they are older and many have health problems before they ever step on a plane."
Time for a new standard?
Because the pressure in an airliner is easy to control, the industry is considering whether it should change the minimum pressure standards to try to prevent medical emergencies.
An FAA rule requires pilots to keep jets pressurized to the level that is equivalent to an 8,000-foot mountain or lower. The rule, FAA officials say, is based on altitude chamber tests performed on healthy airmen decades ago.
But the FAA says it does not monitor planes to see how they are pressurized while carrying passengers.
One study performed by doctors in the 1980s found pressurization differences across the fleet.
Each plane must meet the same strict standard to go into service. But once it is in use, everyday wear and tear can change the way the air flows in the cabin. Even small dents in the floor by the door, where heavy carts are dragged aboard, can make it more difficult to maintain cabin pressure.
The more air the pilot takes from the engines to pressurize the cabin, however, the more fuel it takes to fly. The air also reduces the engine's thrust.
"These planes are flying up to 42,000 feet," says Stanley Mohler of Wright State University School of Medicine in Dayton, Ohio, who has studied the health effects of flight. "When you get up to that area, it takes a lot of fuel to keep the cabin pressurized."
As engineers consider whether the atmosphere inside the cabin could be required to be kept at pressurization equal to 6,000 feet, for instance, to increase passenger oxygenation, the airlines want proof that a change is needed.
"The airlines are going to resist," Mohler says. "If you lower the cabin pressure on many of their airline flights, you're going to burn a lot more fuel."
The aviation industry says that while it is worth studying, there is not yet any proof that changing the pressure will help passengers.
"You have to have some evidence that it's going to be salutary to the passengers," says Russell Rayman of the Aerospace Medical Association.
He calls the FAA's 8,000-foot rule "rather arbitrary" and "a best guess," but he says there is no proof that lowering it would help. "There is no evidence and I think it will be very difficult to get it."
Some people in the industry balk at the idea of changing the rules to meet the needs of people with health problems.
"I feel sorry for somebody who has vascular problems or breathing problems, but maybe they shouldn't be flying," says Dave Heekin, an airline captain. "If you are going to make it comfortable for the most susceptible passengers you're going to have an airplane that you're not going to be able to fly.
"I have compassion for them but you can't do everything to the lowest common denominator."
Who's responsible?
Heekin hopes his passengers begin to take more responsibility for their health. "I'm tired of the flight attendants telling me we have a passenger with breathing problems and we may have to land in Omaha," Heekin says.
Garrett of MedAire says the responsibility shouldn't rest with the airlines, which can't know their passengers' medical baggage.
"I feel sorry for the airlines," she says. "There is no way the airlines can possibly prepare to deal with the kinds of problems and the critical nature of the problems travelers have today. How can they be responsible? They don't know that my Aunt Agnes smokes."
Doctors who have studied the problem agree.
They say two common factors that cause hypoxia are often launched on the ground as passengers prepare to board the plane.
When people drink too much alcohol, the body does not use oxygen as efficiently, leading to what is known as histotoxic hypoxia. And cigarette smoke damages the fragile membranes in the lung where oxygen is exchanged.
People who have smoked for years and who smoke several cigarettes before a flight can suffer what is known as hypemic hypoxia before they board the plane.
Flight attendants say they keep an eye on the "runners" who drink and smoke in the airport bar until the last moments of boarding, then run to catch the plane before it leaves the gate.
"When they get on board they decompensate," says Garrett, who was a flight nurse before starting MedAire. "They get chest pain and in some cases they will have a cardiac arrest."
Blue, a Jackson Hole, Wyo., physician and pilot, says alcohol is a major reason for so many medical emergencies in flight.
"Alcohol should not be served on an airplane," he says. "I can't think of anything worse you could do on an airplane than drink."
Blue has a Web site — Aeromedix.com — with information about hypoxia in flight. And he sells fingertip devices that measure oxygen level in the blood. He began selling to pilots so they could monitor themselves while flying their private planes. But he says thousands of airline travelers have bought the devices, which cost $380, in recent years.
If a healthy passenger suffers any ill effects from hypoxia, it may be anything from a headache to tingling lips to weakness or other annoyances. "But if they have a bad cold or upper respiratory infection, walking pneumonia, coronary artery disease, emphysema, a lot of those things, they'll notice it," Blue says. "Especially with coronary artery disease they will be at significant risk."
He says the airlines should not be "let off the hook" because they do not give any warning to their passengers today about hypoxia or cabin pressurization.
"They can say this flight will be 8,000 feet or 7,500 feet," he says. "Then you could make a choice."
Rayman, a physician on the National Academy of Sciences committee on cabin air quality, offers this perspective: "People with coronary artery disease are flying every day. The great majority reach their destination none the worse. Those with advanced or significant coronary artery disease are at increased risk and should accordingly consult their physicians before planning to travel by air."
