Packing: GI causes lung injury in trained breath-hold divers

[Johan Andersson]

There is a new study on possible risks with glossopharyngeal insufflation:

Glossopharyngeal insufflation causes lung injury i... [Respirology. 2010] - PubMed result

/Johan

 

[trux]

Thank you, Johan. Quite interesting. Pity we don't have access to the full study.

 

[azapa]

Johan: could you sum up this new possible risks in lay terms please?

 

[Johan Andersson]

Johan: could you sum up this new possible risks in lay terms please?

Well, in short, in five out of six divers, pneumomediastinum (which means that air is present in the mediastinum, which is the central compartment of the thoracic cavity) was observed. My interpretation is that a possible cause of the pneumomediastinum could be that there was an alveolar rupture caused by the GI/packing, allowing air to escape into the mediastinum. Rupture in some other part(s) of the airways besides the alveoli is also a possibility.

The authors of the study writes: "The single subject, in whom a pneumomediastinum was not detected, was demonstrated separately to not be proficient at GI". It could mean that this diver was unable to pack his/her lungs to such an extent that alveolar rupture occurred. This would be in accordance with what is known about lung volumes, airway pressures, and risks for pulmonary barotrauma/volutrauma.

Furthermore, the authors state "The long-term effects of this barotrauma are uncertain and longitudinal studies are required to assess cumulative lung damage". This means that even though the divers did not experience any acute symptoms, it can not be excluded that there could be long-term damage to the lungs from e.g. repetitive pneumomedistinum. Overinflation of the lungs by GI above the TLC is a relatively new practice (at least within a larger population), and therefore not much is known about the long-term risks with this practice.

 

[azapa]

that's interesting Johan, thanks very much. Despite being a relatively proficient freediver I am also "unable" to pack, therefor I identify with the odd one out in that study.

Thanks

 

[fpernett]

This article supports the real concern of heavy lung packing. The increase over VC was at least 20% and a maximal of 29%. The only freediver without evidence of barotrauma was the only one that can not increase his VC with packing.
Just attached one of the pictures, and it really worries me.

I have the full article, if anyone interested PM me.

 

[trux]

Frank, I am just not sue if I interpret the picture correctly. Are the white spots, bubbles of air in the mediastinum? Or is it something else. And what exactly is the arrow pointing to? Is the rupture near the heart?

 

[Waterenthusiast]

The white spots look like ribs to me.

 

[Johan Andersson]

trux, the white spots within the black lungs are tissue in the lungs (e.g. blood vessels, etc.) and is not of concern - it should be there. You can also see the ribs along the margins of the lungs. The arrow points at the pneumomediastinum. You can see the trachea in the middle of the figure (the elongated, oval, black shape in the middle). Next to it, where the arrow points, you can see a smaller/thinner, black "stripe". That is the air forming the pneumomediastinum.

In pneumomediastinum, after alveoral rupture (or rupture in any other part of the airways), gas escapes into the surrounding tissue (interstitial pulmonary tissues). This gas may track along the airways and blood vessels, into the region where the bronchi and blood vessels enter the lungs (the hilar region). Then it can move towards the mediastinum and neck region, which is what you see in the figure (gas tracking along the trachea).

 

[fpernett]

Frank, I am just not sue if I interpret the picture correctly. Are the white spots, bubbles of air in the mediastinum? Or is it something else. And what exactly is the arrow pointing to? Is the rupture near the heart?

All that is black is air, in the middle is the trachea, and the arrow is pointing a space of air, next to the trachea, that is the pneumomediastinum. (As Johan explain it).

The most important conclusion, is that there is alveolar rupture during heavy packing. And that is not good.

The next question is to find out if with light packing, there is also alveolar rupture.

 

[azapa]

Johan, Frank:

What happens to this trapped air? Does it dissolve away into tissue?
The Xrays shown are taken with packed lungs or soon after packing?

Thanks

 

[Erik]

Pretty good evidence to stop doing it. On the other hand, what happens to the air? I did tons of packing years ago and I think I'm fine ie: no strokes. Lots of other divers have done lots more and still do, with no apparent problems. Maybe we have all been affected somehow.

 

[efattah]

Dominque Ventzke DID get a stroke after packing for dynamic. Barely 25m in he got paralyzed in half his body and was rushed to the emergency room....

 

[fpernett]

The air is absorbed. The main problem is the alveolar damage and where the air can travel, you can get an air embolism from this (As Eric mention it).

I agree with Erik (with K) this paper shows good evidence for stop doing this at least the heavy packing

 

[stingaree]

Very interesting article indeed. My interpretation of it would be that an increase in lung volume capacity (by packing or just repetitive freediving) isn't really desired. I have a documented slight increase in volume over the last few years, which actually seems to worsen my spiro test and I ALSO SUFFERED A SPONTANEOUS PNEUMOTHORAX several years back and it was suggested, that it could be from of weakening of the tissue caused by this increase as there were no other abnormalities spotted on CT's (such as blebs etc.) NO PACKING (AND NEGATIVE FREEDIVING) FOR ME. EVER!

 

[adelito]

I thought packing was moré for having air to equalize with?
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[Erik]

Here's a few reasons to pack: equalizing at great depth, more oxygen, stretching, and buoyancy control.
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[Lil Dragonfly]

I pack for the same reason I carried a stuffed animal around as a baby, and (even now) refuse to sleep without a night light: I find it to be comforting.

Not everyone does though. Many of my friends find it to be awkward-feeling.

 

[B-J]

Last year they started a study in Norway which to me seems identical to this. I did a dry static with max packing while I was in a CT-machine. They also did ultrasound of my thorax during the static. They had a lot of chords attached to me and they even stuffed somekind of hose into my vein. (From my elbow all the way into the chest) I think they tested 5 persons. All but one had air escaping, and one had quite a lot of air escaping. They too didn`t seem to be worried about the air itself, but the damage to the lungs in the long run.

 

[Goran Colak]

That might be worrying, and true, needs more research do, on a way bigger sample of subjects, for my taste subjects has to be high level freedivers, comfortable with packing. But than again you are quite naive if you think world class results comes for free, and without bill to be paid later in life. There is no such thing as high level sport that is healthy...