Immersion Pulmonary Edema (IPE) - unknown cause, known killer

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Jax,

Thanks for posting this and for helping to increase the visibility of IPE.

As you noted, we're conducting a study on IPE and would welcome anyone who thinks they've experienced this to contact us. Our contact info is on our website, linked below.

I think that it's important to recognize that a number of factors can be at play when a diver or swimmer experiences pulmonary edema. On the surface, gravity tends to pull blood into the lower parts of the body. In the water,this effect is reduced or negated, and blood becomes more evenly distributed in the body. This results in a significant influx of blood into the lungs. If the pulmonary arteries are unable to dilate sufficiently to compensate for this, the resultant pulmonary hypertension can cause pulmonary edema, as you noted. In cold water, a swimmer or diver experiences peripheral vasoconstriction, which magnifies this effect by shunting blood away from the extremities and into the core.

Immersion plays a greater or lesser role depending on the individual's susceptibility. For example, in a superbly conditioned triathlete like Kat Calder-Becker, who we studied, the theory is that extremely high cardiac output combines with individual susceptibility to cause SIPE. On the other hand, a diver with underlying cardiac disease who's in equilibrium on the surface can suffer pulmonary edema on a dive if immersion, work level, temperature, and low cardiac output combine to overwhelm the pulmonary circulation. Immersion would certainly be a factor, but this would not be considered true immersion pulmonary edema.

At any rate, once pulmonary edema occurs, the treatment is essentially the same no matter what the cause. Qualified individuals should provide high-flow oxygen via mask and be prepared to support ventilations and circulation should the need arise. Sometimes, the positive pressure from assisted ventilation can be beneficial. This can be accomplished by using a CPR pocket mask or other barrier device. Some pocket masks have oxygen inlets and can be attached to an O2 bottle to increase the amount of oxygen the diver is receiving. As you noted, if a device like this isn't available, it can be beneficial for a qualified rescuer to don a nasal cannula and provide mouth-to-barrier ventilations. The American Heart Association encourages the use of CPR barriers but also notes that there has not been a reported incidence of disease transmission from direct mouth-to-mouth breathing. From personal experience, however, the presence of bodily fluids like vomit and mucus will make a rescuer very thankful for a barrier device.

CPAP devices and bag valve masks like the one pictured require specialized training and practical experience to be properly employed, and so should only be used by trained rescuers.

IPE and SIPE remain very rare, but prompt recognition will definitely increase a victim's chances of a positive outcome. Thanks again for posting this.

Best regards,
DDM
 
CPAP devices and bag valve masks like the one pictured require specialized training and practical experience to be properly employed, and so should only be used by trained rescuers.

IPE and SIPE remain very rare, but prompt recognition will definitely increase a victim's chances of a positive outcome. Thanks again for posting this.

Best regards,
DDM

This bears repeating!!! :thumb:
 
I think the biggest problem with a blanket recommendation for positive pressure ventilation in the presence of significant dyspnea after diving is that there are other causes of dyspnea that can be worsened by positive pressure -- pneumothorax being one of them. If the person is coughing up pink foam, that would be strong evidence for a pulmonary edema process, but the majority of IPE patients I've read about aren't doing that. Once someone is on site with a stethoscope, a more solid diagnosis can be made, and it is definitely true that positive pressure ventilation can have amazing results with patients in pulmonary edema.

If you have a patient with no pulse, I'd still go first for CPR. Oxygen delivery to the lungs is not going to be effective in the absence of spontaneous circulation.
 
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Jax, given what little info has been released about this incident, it's rather presumptuous to jump to a diagnosis of IPE.
Several other medical conditions could be consistent with what was described in that article.
IPE should definitely be on the differential, though.

We should also bear in mind the track record of journalists reporting on scuba incidents and medical issues. The reporter is unlikely to have training in either discipline. As a result, it's easy to introduce inaccuracies into the story.
 
True.


I am saying we need awareness of what this is, so that when something happens as it did to DeniseGG, for example, it's a consideration.
 
I am saying we need awareness of what this is, so that when something happens as it did to DeniseGG, for example, it's a consideration.
Just to play Devil's advocate for a second...
How will a non-medical person knowing about IPE change the first aid approach to a diver who complains of breathing difficulties?
 
No initial change

For me, the first step would be slapping on the O2 and monitoring.

If the person is coughing up stuff, and still getting air in, then just monitor and pray.

If the person seems to be losing the fight to breathe, I'd be having someone on the pulse continuously, and absolutely make sure that rescue breathing (bag, or mouth to mouth) is ready to jump in. Upon loss of consciousness, rescue breathing commences as the pulse is monitored.

As I was trained, you go to chest compressions immediately that there is no pulse. . . . 100 times a minute. But if there were any suspicion of IPE, I would make the rescue breathing of equal priority. Circulating oxygen-deprived blood isn't doing much.
 
I have a friend (kinda a far relative) that had an episode that I assume was IPE. He is overweight guy (not grossly but VERY far from slim), not very active but doesn't need to catch his breath after walking up the stairs, in late 30s. Started diving in his teens but not diving now on regular basis. Was on Hawaii vacation and went diving. Underwater felt out of breath but continued the dive for a little bit. Signaled to DM that he was in trouble when he felt worse. Upon slow ascent was severely out of breath and started coughing up fluids (no blood). Was helped to the boat, couldn't swim himself, dizzy. Felt better after coughing up bunch of fluids, some O2. Boat staff checked his reg (rental) and said it was leaking and he inhaled bunch of water without realizing it. I don't have enough of experience but question this "diagnosis". Can diver really inhale this much water without realizing it? My feeling is that it might've been IPE and everything in his and his wife's recollection of the incident fits the profile. What do more experienced divers think? If it was IPE is he in higher risk of repeat episode? Anything to check before return to diving (besides getting in shape)?
 
I have a friend (kinda a far relative) that had an episode that I assume was IPE. He is overweight guy (not grossly but VERY far from slim), not very active but doesn't need to catch his breath after walking up the stairs, in late 30s. Started diving in his teens but not diving now on regular basis. Was on Hawaii vacation and went diving. Underwater felt out of breath but continued the dive for a little bit. Signaled to DM that he was in trouble when he felt worse. Upon slow ascent was severely out of breath and started coughing up fluids (no blood). Was helped to the boat, couldn't swim himself, dizzy. Felt better after coughing up bunch of fluids, some O2. Boat staff checked his reg (rental) and said it was leaking and he inhaled bunch of water without realizing it. I don't have enough of experience but question this "diagnosis". Can diver really inhale this much water without realizing it? My feeling is that it might've been IPE and everything in his and his wife's recollection of the incident fits the profile. What do more experienced divers think? If it was IPE is he in higher risk of repeat episode? Anything to check before return to diving (besides getting in shape)?

Hey, Vlad, how about you ask your friend to click that link at the bottom of the OP and have him talk to Duke Diving Medicine?
 
No initial change

For me, the first step would be slapping on the O2 and monitoring.

If the person is coughing up stuff, and still getting air in, then just monitor and pray.

If the person seems to be losing the fight to breathe, I'd be having someone on the pulse continuously, and absolutely make sure that rescue breathing (bag, or mouth to mouth) is ready to jump in. Upon loss of consciousness, rescue breathing commences as the pulse is monitored.

As I was trained, you go to chest compressions immediately that there is no pulse. . . . 100 times a minute. But if there were any suspicion of IPE, I would make the rescue breathing of equal priority. Circulating oxygen-deprived blood isn't doing much.


Hey, does anyone have any ideas? This is a *discussion* thread . . . :D
 
https://www.shearwater.com/products/perdix-ai/

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