What does it mean to "blow out" a lung?

November 15, 2006 4:20 PM

What does it mean when a paramedic applies oxygen to someone in respiratory distress and it "blows out" the lungs?

My aunt passed away on Sunday after battling emphysema for many years. Something my uncle told me about her last moments was confusing but I didn't feel it was appropriate to ask him, and Google isn't yielding any results.

He said that she went into respiratory distress during the night, so he called 911. When paramedics came, they attempted to give her oxygen, but it "blew out" her lungs. They then attempted to intubate her, but it was too late.

What did they mean? Did the pressure of the oxygen they tried to force into her lungs literally blow holes in each lung? I can imagine her lungs were like putty these last few years, but can anyone tell me exactly what they could have meant by the "blew out" description? Thanks in advance.

posted by forensicphd to Health & Fitness (4 answers total)

When folks have emphysema, the lung tissue is abnormally stiff and brittle. High pressures, such as those used in positive pressure ventilation can do what is known informally as 'rupturing a bleb.' This rupture allows the airway to communicate with the pleural space. The result is pneumothorax, often tension pneumothorax; persons with emphysema already have respiratory compromise, meaning that the loss of the ability to inflate a lung can be fatal.

I'm sorry to hear your story.
posted by ikkyu2 at 4:24 PM on November 15, 2006

Best answer: I'm sorry for your loss as well. To expand on ikkyu2's answer, the word you're looking for is barotrauma - "a well recognized complication of mechanical ventilation." Basically, what "blows out" are the alveoli, the tiny air sacs in the lungs where O2/CO2 gas exchange takes place. Once that air gets into the cavity surrounding the lungs (the "pneumothorax" condition), its pressure against the lungs makes them harder to inflate. When the air's pressure gets too strong inside the lung cavity, it causes the lung and/or lungs to collapse.

EMTs have to watch out for a similar problem when using positive pressure ventilation in infants and small children.
posted by mediareport at 7:39 PM on November 15, 2006

After a near-fatal car accident I had, with a rib puncturing one of my lungs, I had a pneumothorax. They put a tube in through my ribcage, in order to bleed off air and fluid that were in my chest cavity (and were preventing the lung from re-inflating). I had to do breathing exercises, and it still took a few days before my lung re-inflated. It took several weeks before it was close to normal. I'm sorry for your loss.
posted by Alt F4 at 4:56 AM on November 16, 2006

One more point to add here. There's another possibility that doesn't have to do with barotrauma ( which would only occur if someone was actively pushing oxygen into her lungs by "bagging her" ).

Healthy people have two drives to breathe: too much carbon dioxide or too little oxygen. People with emphysema are tolerant of carbon dioxide, so too little oxygen is their only drive to breathe. If someone with severe emphysema is given a large amount of oxygen, say by a mask that fits over nose and mouth, that "low oxygen" drive to breathe gets knocked out, and they develop dangerous buildups of carbon dioxide. This can make them sleepy and less responsive, further decreasing their drive to breathe. The remedy for this is to intubate her.

I grant you, though, that this wouldn't normally be called "blowing out her lungs."

One final point to note, is that people with severe emphysema are prone to spontaneous "blow-outs" (pneumothoraces) which may even have occured before the EMTs arrived, and may have been the cause of her distress in the first place.
posted by cameradv at 8:42 AM on November 16, 2006