Immersion Pulmonary Oedema?

cedricverdier

Hi all,

I just found the following information:

Immersion Pulmonary Oedema
Cause. This is an uncommon condition which presents as sudden onset of dyspnoea whilst immersed. First described in a group of divers by Wilmshurst in 1984, cases of immersion pulmonary oedema have subsequently been reported in both divers and long distance swimmers. Cold water was thought to be the prime causative factor but cases have since been reported in divers and swimmers who were working in warm (23-290C) water. The mechanism of causation is currently unknown but may be due to stress failure of pulmonary capillaries induced by a combination of cold, exercise, immersion, over hydration. A high PiO2 and pulmonary overinflation may be contributory factors. Immersion pulmonary oedema may be associated with the development of hypertension.
Prevention. Over hydration, especially prior to cold dives involving high workloads should be avoided. There is evidence that this condition may recur and as such individuals who have developed pulmonary oedema whilst diving should be advised not to dive again.

Does anybody have more information on this topic?

Cheers

__________________
Cedric Verdier
PADI Course Director, ANDI-IANTD-PSAI-TDI-DSAT-DAN-NAUI-CMAS Instructor Trainer
Trimix (CCR and OC) and Cave Diving Instructor Trainer

www.CedricVerdier.com
DIRrebreather member

jhaaja

Something can be found from the web:
http://en.wikipedia.org/wiki/Pulmonary_congestion

The symptoms seem to be similar to pulmonary O2 tox.

JH

dteubner

Hi Cedric,

Where did the quote come from?

Immersion pulmonary oedema is well recognised but pretty rare in people with normal hearts and circulations.

Pulmonary oedema occurs when the delicate balance of forces in the pulmonary capillaries change so that fluid leaves the circulation and accumulates in the alveoli. Most commonly this happens because the left atrial pressure rises (either because of fluid oveload or because the left ventricle stops working properly due to ischaemia for example)

Immersion removes the effects fo gravity from the circulation and has the effect of moving about 500ml of blood from the peripheries to the core. Most people can cope with this just fine but some people with heart problems may fail to cope with the exess fluid and some pulmonary oedema may ensue.

Cold causes constriction of the systemic circulation again shifting fluid to the core. Hyperoxia has some similar effect.

It may well be that a number of diving deaths are partially caused by this problem. I.e. people with undetected coronary artery disease dive, have their circulation stressed by immersion, cold, hyperoxia or whatever, precipitate pulmonary oedema, feel short of breath, panic and drown.

It may be that a number of the 'heart attacks' which db8us, for one, is so fond of deriding actually follow the above course.

Dave T

cedricverdier

Hi Dave,

The text comes from the Royal Navy diving Manual (Accident management).

Cheers

__________________
Cedric Verdier
PADI Course Director, ANDI-IANTD-PSAI-TDI-DSAT-DAN-NAUI-CMAS Instructor Trainer
Trimix (CCR and OC) and Cave Diving Instructor Trainer

www.CedricVerdier.com
DIRrebreather member

leeflow

Hello all,
I'm one of the lucky few who have had attacks of Pulmonary Oedema. I've had the experience about 5 times in the last 16 years or so. The last was while I was on a Dolphin SCR. I do not expect to ever have one again. After the last episode I did as much studying about it as I could. Unfortunately there is little written, only anecdodal information. I've worked with pulmonary and hyperbaric experts and I've had every pulmonary and circulatory tests available and I passed them all quite well. I also get a dive physical on a yearly basis.
The information I came up with would take more time than I have today to tell but here is a rundown of my conclusions.
Over hydration and a slightly elevated blood pressure seems to be the causes of SIPE. (Submersion Induced Pulmonary Edema). US military cadets preparing for a 2 hour swim suffer from edema because they have been overhydrating prior to the swim.
An increase in inhilation effort may also be a contributing factor. (an anesthesiologist can induce edema by increasing the inhilation effort of a patient, and it only takes 3-4 breaths).
This was once thought to be a cold water induced. My theory is that it's difficult to be overhydrated in a tropical setting due to sweating.
I also studied HAPE (High altitude Pulmonary edema), both are effected by a change in the presrure of the capillary/alveolar walls.
The real question about any diving is if the risk is too great. We all take risks when we do anything. My specialists agree that the risk is too small to worry about.

Jim

UWSojourner

Anyone care to elaborate on what "over-hydration" means?

Drinking plenty of hydrating liquids has been drilled into everyone to avoid de-hydration which is a a risk factor in DCI. How much do you have to drink to be over-hydrated?

Sutty

I read about this in "Diving and subaquatic medicine" by Edmonds, Lowry et al, following Rob Davie's death on the rebreatherworld trip. Its well worth reading, and goes some way to explaining why there might be such a high proportion of "heart attacks" in diving deaths. A heart attack/angina attack or acute rhythm disturbance which would be manageable if not immersed could be much more severe or fatal in water (and potentially even worse once surfaced but with head out of water). What we seem to lack is the serious non-fatal incidents which would support this, however these may be under-reported compared to deaths.

Neil

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leeflow

Hello again

It is correct that staying hydrated is an important defence mechanism to prevent DCS. How much is too much is a good question. I did not encounter any research that indicated what is the right amount of fluid to drink prior to a dive. The fact that SIPE is such a rare condition, I don't think that anyone should worry about it. I suppose that if a diver has been diagnosed with a water retention problem, then maybe they should talk to a physician about it, but remember that MOST physicians know less about SIPE than you now know. I got lucky in my research by finding one Dr. that had some experience and another who liked a challange. Hopefully more physicians will learn about SIPE and prevent miss-diagnosis.

The only treatment is to get the diver out of the water in a sitting position. O2 can be administered but the symptoms will dissapate.

Jim

Sutty

At a purely theoretical level, if you got pulmonary oedema in the water and had back-mounted counterlungs, you would be better on your back as the +ve pressure helps to reduce the oedema. I suppose you might also be better staying on your back on the surface with a fairly full loop to maintain some +ve pressure while getting help to you.

Neil

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abowie

I find it very hard to believe that anyone with a normal heart and kidneys could drink enough fluid to put themselves into pulmonary oedema. The normal homeostatic mechanisms are just too effective at maintaining circulatory volume and osmolarity.

There must be more to it than just that.

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Andrew Bowie

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