Rescuing unconscious diver question

[MB]

Or they're afraid of a little water up the nose. Good morning! You know what we have to schedule...........

YUP - after reading this thread, I think we might have waited too long.... eeeck!

 

[victor]

This statement is correct, but a rapid, uncontrolled ascent to the service will not allow the air that's still in the lungs enough time to escape through the small opening of the trachea, larynx, nasal passages. The lining of the lungs will give way before the air can escape.

I am surprised by this.
Given the drag an uncontrolled ascent is never going to be that quick. I am guessing but I cannot see it being faster than 1m per sec (3ft per sec), olympic swimmers don't do 2m per sec.
I assume the last 10m are the worst as the lungs would have to expell 1 full lung full of air in 10 seconds.
Even at 2 or 3 times this rate of ascent I doubt whether this is an issue unless the airways are constricted.
If the divers airway is constricted then they are suffocating. Delaying there arrival at the surface for 5 minutes is going to be fatal anyway.
If the diver is dead then they are not going to be holding there breath.

Do you have any evidence to back up your position?

 

[Dive-aholic]

http://www.emedicine.com/emerg/topic121.htm

http://www.iaff.org/safe/content/DivingMedicine/diving_medicine.htm

http://www.scubamed.com/divess.htm

Too many unknowns in this scenario. We don't know why the diver is unconscious, how deep we are, whether it was witnessed. Pneumothorax may not occur in every set of circumstances, but the possibility exists. I'd rather ascend in a safe, controlled manner for both me and the diver.

 

[KrisB]

Get face to face, the inflator will be right there. It also allows you to see if the mask is flooded and watch for any facial expressions/changes.

Why do class victims almost always lie face down?

I'd guess that's mostly because the training seems to be to ascend with them facing away from you...

The reason for that? I can only surmise it has something to do with them recovering during the ascent and panicking.

 

[Walter]

I'd guess that's mostly because the training seems to be to ascend with them facing away from you...

The reason for that? I can only surmise it has something to do with them recovering during the ascent and panicking.

Poor choice, IMO.

 

[kidspot]

Walter, MD & NetDoc - THANK YOU so much for your comments... I had never even heard, much less considered many of them ...

Walter - Shall I take it that your students perform these ascents with a variety of victim positions?

I have learned a lot more than expected in this thread, and am wondering where else I have large gaps in my knowledge now... guess I'll just have to keep asking questions around here

Aloha, Tim

 

[The Chairman]

Hey Tim,

Come invade the Keys with us! We'll show you some moves we don't dare mention here!

 

[kidspot]

Can't tell you how tempting that is ... if I could drive there I'd be coming ...

So when is the next "invade Hawaii" planned for?

 

[victor]

http://www.emedicine.com/emerg/topic121.htm

http://www.iaff.org/safe/content/DivingMedicine/diving_medicine.htm

http://www.scubamed.com/divess.htm

Too many unknowns in this scenario. We don't know why the diver is unconscious, how deep we are, whether it was witnessed. Pneumothorax may not occur in every set of circumstances, but the possibility exists. I'd rather ascend in a safe, controlled manner for both me and the diver.

Interesting articles, they seem to support my argument that an uncontrolled ascent might be the best option for the injured diver.
Yes there is a very significant chance that the diver will have a severe case of DCS however a pulmonary embolism seems from these articles to be an unlikely event.

From the articles you quoted

Spontaneous pneumothorax is an inherited disease which leaves some individuals with weak areas of the pleural lining of the lung. Yes this might be the cause of the problem, in which case any ascent is going to be bad news, still we can’t live at depth forever so they will have to come up sometime.

“Pulmonary over inflation is most commonly seen in the context of inadvertent breatholding during an uncontrolled ascent by an inexperienced or poorly trained diver.”
Well as long as our diver is breathing they are not holding there breath.

“During the numerous dives involved in the recovery of wreckage from TWA Flight 800, rapid ascents resulting in AGE were uncommon even under stressful conditions.”
Age = arterial gas embolisms.

I think this deserves further discussion, I am definitely not recommending it.
If it is going to take you 5 minutes to get safely to the surface should the injured diver stay with you for that long?

 

[Walter]

Interesting articles, they seem to support my argument that an uncontrolled ascent might be the best option for the injured diver.

Who will be taking care of trhe injured diver? What's the point of sending him up to die on the surface?

If it is going to take you 5 minutes to get safely to the surface should the injured diver stay with you for that long?

5 minutes at 60 feet/minute - that's 300 feet. If you're that deep, you'll need more than 5 minutes of deco. My personal choice is if I had less than 5 minutes od deco obligation, I'd blow it and take the victim to the surface. I wouldn't ever recommend anyone blow by a deco stop, but I do recommend skipping safety stops and ascending at the emergency ascent rate. It shouldn't take 5 minutes to get to the surface (assuming you aren't inside a cave or wreck when you can't head straight up) in an emergency. It should either take about 2 minutes or less or a whole lot longer than 5 minutes.

Walter - Shall I take it that your students perform these ascents with a variety of victim positions?

Of course. How else can you teach this material? MB & I will be giving an instructor level Rescue Seminar soon. Keep an eye out for an announcement. Come to Florida for it.