Oregon Live wrote:Although witnesses said Long drank that night and toxicology results are pending, an autopsy by Dr. James Olson of the Oregon State Medical Examiner's office determined she died of an air embolism "due to inhalation of a helium gas mixture from a pressurized canister."
What happens, Olson explained, is that the pressure in the tank sends the helium to the lungs with so much force it can rupture them. Once the lungs are destroyed, the gas can get into blood vessels, sending tiny bubbles to other major organs that can cause additional damage.
Think about how quickly it takes to fill a Mylar balloon with a helium tank, Olsen said. Then think about that same force hitting a person's lungs.
That force is key, said Dr. William Hurley, medical director of the Washington Poison Center, which is why sucking helium from a balloon doesn't carry the same risks. Instead, that vibrates the vocal chords, changing the timbre of a voice and producing a cartoon-character sound.
"I've never heard of a case of an air embolism being caused by a balloon," he said.
Still, helium is a dangerous gas when consumed, said Dr. Mark Morocco, associate professor of emergency medicine at the Ronald Reagan UCLA Medical Center in Los Angeles, which is why it's best to avoid inhaling it at all.
"It's worse if it's pressurized, but it's not safe if it's in a balloon. You can put helium in a bag and cover your head under normal atmospheric pressure and you'll die sounding like Donald Duck," he said. "I would not use helium for anything other than filling up party balloons."
That's how many mail-order suicide kits work. The controversial devices operate when someone places a plastic hood over his head and uses tubing to connect it to a helium tank, but in those instances, the oxygen in the lungs is slowly replaced with helium, causing the person to suffocate.
And as for the others inhaling the helium at the party? They likely didn't create strong enough of a seal with their mouths to send the gas into their lungs with the same force as Long did, Olson said -- and were very lucky.
"Some people get away with it," he said. "Occasionally it happens."
Deaths from inhaling helium are very rare -- so rare, in fact, that the American Association of Poison Controls Center groups helium with other "simple asphyxiants" such as carbon dioxide, methane and propane, said spokeswoman Loreeta Canton. Three deaths from simple asphyxiants were recorded nationwide in 2010.