Diver pulled from Massachusetts training pond

[Ayisha]

Not necessarily. Even without holding one's breath, significant congestion or an asthma attack can also prevent effective exhalation that can lead to a lung overexpansion injury.

 

[flots am]

Not necessarily. Even without holding one's breath, significant congestion or an asthma attack can also prevent effective exhalation that can lead to a lung overexpansion injury.

Both conditions would mean that the diver should not be diving, and has nothing to do with ascent rate safety on a no-deco dive.

flots

 

[DandyDon]

It was mentioned in post #1 that a heart attack was suspected, and in post #3 that he surfaced after complaining to his diving partner that he was having buoyancy problems, then bloody face, then passing out in the water.

 

[Notso_Ken]

Are you certain about that? If you are breathing compressed air and surface too quickly you can have issues even without a deco obligation. 30 feet in 30 seconds would not be your best option. I could be wrong though.

When I was certified, 60 feet per minute was the standard ascent rate. Yes, 30 fpm is safer, but 60 is not going to kill you by itself. If you hold your breathe, it is not the ascent rate that kills you.

 

[gkwalt]

Townseley, Power, Hooke, Mariotte, and Boyle said that pressure was inversely proportional to volume. The total vital capacity(TVC) of the lungs (the total amount the lungs can fill) is about 6 liters. If a panicked breath holding diver takes a deep breathe, holds their breathe, and then ascends to the surface, his TVC is now 12liters!. Pulmonary expansion injury may present as hemoptysis (bloody sputum). Then the lung ruptures, then bleeding ensues. In IMHO, this is clearly not DCS (the bends) but a lung over expansion injury.
It is disheartening to hear about someone succumbing to a diving accident, but it re-enforces the first commandment of diving: "Never hold your breathe while diving"!

 

[Ayisha]

Both conditions would mean that the diver should not be diving, and has nothing to do with ascent rate safety on a no-deco dive.

Actually, I was referring to the post that is quoted below. It is possible to have a Lung Over-Expansion Injury without holding your breath.

Unless you're their doctor, it's not up to you to decide if any diver should be diving or not. Many divers with asthma do have medical clearance from a doctor to dive.

Unconscious divers can also embolize during the ascent due to a closed airway.

But unless you had a deco obligation (unlikely), that isn't a problem unless you hold your breath...

 

[flots am]

It is possible to have a Lung Over-Expansion Injury without holding your breath.

With an open airway and no medical problems, I don't see how that's possible.

Unless you're their doctor, it's not up to you to decide if any diver should be diving or not. Many divers with asthma do have medical clearance from a doctor to dive.

Certified divers can do whatever they want, but I'm not required to dive with anybody I don't beleive is fit to do so.

Students are required to obtain a signed medical form, but I am not required to take them diving if I feel it's unsafe, even if the form has been signed.

They can always try somewhere else.

flots.

 

[rickgillyon]

It is possible to have a Lung Over-Expansion Injury without holding your breath.

Not terribly likely though. Seen a lot of fast ascents, had one myself, generally not an issue so long as you keep breathing or at least keep the airway open. Sure, you can look at the long odds too if you like.

 

[usmarinekurt]

There is a plaque for Ed on the conning tower of the U853
its the first thing we saw when we dove it Sunday and today

Very nice whoever put it there

 

[wtcreaux]

Many divers with asthma do have medical clearance from a doctor to dive.

I am one of these, having had asthma since 1960s. HOWEVER, my medical release is based on a snapshot in time (the time my physician saw me). Common sense dictates that IF I'm having shortness of breath/difficulty breathing/wheezing, that I NOT dive (until my airways have relaxed (my personal criteria adds 24 hours)).

The same can be said for those with a history of cardiac disease or angina. Though their physician may clear them, common sense dictates that IF chest pain is present or occurs, the dive is OVER.

Having said all the above, having read too many reports of fatalities (from medical events), maybe common sense ain't too common.....