What do you do if a convulsion happens to your buddy?

Genesis

Here's reality guys...

4 minutes is pretty much the line for severe, permanent impairment on "not breathing".

Now assume you're at 100' when this happens. A normal 33fpm ascent takes 3 minutes to get you to the top.

People talk about rescue breathing in the water - have you ever tried it as a "simulation"? Works reasonably well in a pool. Now try it in 3' seas. Yeah, right - you pull the mouthpiece you DROWN the guy. It doesn't take much water down the windpipe to lock up the airway and that's the end of that. In reality, until the victim is out of the water, there's little you can do in terms of an effective rescue effort.

So here's the deal, as I see it. The real key is "are you breathing"? If the answer is "yes", then you're coming up at a safe rate and doing your stops if I can manage to control both of us in the water column. I'm only going to blow that off if gas supplies get in the way. If you're actively seizing I'm not moving you in the water column until that stops, because your airway is locked shut.

If you're NOT breathing, then you're probably screwed if the incident happens deeper than 60' or so, as there simply is not enough time to do a reasonable ascent, get you where you can be helped, and apply the help. Yes, there's a CHANCE, but its vanishingly small.

All of this goes into the split-second decision as to the degree of personal risk as a rescuer I'm willing to take. If you're not breathing, have a significant deco obligation, and are at 200', I'm not going to kill myself in order to attempt to rescue a corpse, and if you attempt to rescue my corpse under similar circumstances you can bet I'll haunt you (if you survive) for your folly.

This may sound harsh but its reality, and one that all of us really ought to face and talk about with those we dive with.

__________________
"A venturesome minority will always be eager to get off on their own, and no obstacles should be placed in their path; let them take risks for Godsake, let them get lost, sunburnt, stranded, drowned, eaten by bears, buried alive under avalanches - that is the right and privilege of any free American."
http://www.denninger.net
http://www.diversunion.org/liability.htm - Fix the Diving Cert racket

bobmaggi

I can't speak on a toxing diver but I can talk about drowning and recovery.

Last year my wife aspirated water at 85-90 feet due to her failure to purge her regulator after she dropped it due to numb lips (55 degree water) and not biting down on the mouthpiece enough. She started coughing causing her to drop her reg. What happens after coughing is she immediately inhales but with no reg only gets water. She paniced and refused her regulator when I held it up for her. At this early stage I didn't realize there was a problem until she pushed her regulator away that I was holding in my hand up to her face. I tried to force it into her mouth with the purge depressed and started to pull her up. In those few seconds I needed about two more sets of hands. It was all I could do to hang on to her and hold the regulator.

Bouyancy control went out as later review of the dive computer showed a ascent from 83 feet to the surface in under 30 seconds. An embolism for her wasn't a problem, she emptied her lungs of air on the way up dispite my holding the regulator in her face. She ended up passing out around 30 feet.

After pulling her through the water over 250 feet (against the current) I got her to the boat. Rescue breathing on the surface was impossible due to the current and waves. At the time I believed that getting her to the boat was the most important thing. We stripped her gear off, got her into the boat and I started CPR. At this time she hadn't been breathing for several minutes. I cleared her lungs of water and continued to perform rescue breathing since we got a heartbeat.

After several minutes of purging water and continuing breathing for her, she would start to occassionally take a breath on her own. By the time the CG got there, she was having labored breathing and we were giving here 50% O2 from an extra deco bottle (the charter boat didn't have O2 or even sissors in its First Aid kit!)

The final outcome is that she made a complete recovery after 12 days of being unconcious in the hospital and a 3 hour chamber run.

Overall the lesson I learned was that you do the best you can do considering the current circumstances and get the person into medical hands ASAP.

Bob

PS - She still wants to dive, however she has decided that she will be a warm water diver from now on!

dteubner

Amazing story Bob with a happy outcome. Sounds like you did a great job.

The four minute time is about cardiac arrest, not just respiratory arrest.

In a cardiac arrest the brain stops getting oxygen straight away.

Even after a seizure there is still a whole heap of oxygen in the lungs, as much as 8 litres in most people who were running a setpoint of 1.3 with full lungs. Even after a maximal expiration there may be a couple of litres. If someone is unconcious it will take minutes and minutes before this reserve is exhausted. Only once the reserve is exhausted will the brain be exposed to hypoxia and inevitable death after some time.

In other words, if you just stop breathing at depth it may take 15 minutes or more before your brain becomes hypoxic enough to kill you.

If hour heart stops, on the other hand, it is pretty much impossible to perform the ascent, rescue, and necessary treatement.

dave T

Genesis

You're right, but the problem is that a tox hit is not in and of itself going to stop you from breathing - inhaling water, however, will.

So if you tox and are breathing afterward, there is no emergency per-se - and blowing deco to take you to the surface is exactly the wrong thing to do.

If, on the other hand, you have stopped breathing, then either:

1. You likely have quite a bit of water in your lungs (you've drowned) in which case you're in deep doo-doo as the enriched O2 gas isn't there any more, OR
2. The cause of your breathing cessation was not a tox hit, but something else, and again, you're in deep doo-doo (the most common cause is a coronary incident, of course, although going hypoxic or hypercapnic will do it too)

In both cases (1) and (2) if you have no decompression obligation of substance then you've got a shot with the "go for the surface NOW!" approach. If I see you tox and you've got no significant decompression obligation you're going up as soon as I can ascetain your airway is open, and I'm going with you. No problems there.

But that's not the scenario that's being worked here.

Let's be honest here guys - I've timed simulated rescues before (for grins and giggles) coming off the bottom at ~30' (with a friend as a "let's see how bad this really is") and by my stopwatch getting the victim out of the water and into the boat, from the time of the original incident is noted, in less than five minutes is almost literally a miracle - and that's from 30' when the guy on the boat KNOWS we're fixing to do the exercise!

Now take that same incident and move it down to 100' or more and things get a LOT dicier. Then add a deco obligation to this and its even worse.

IF you had a chamber on the boat you could take the victim up immediately, shove 'em (and YOU!) in the chamber with a tender, blow 'yall back down and perform all the interventions you have available and there'd be a decent shot. But without that you're going to be trying to restart respiration (and possibly circulation) while they're "fizzing" - without advanced intervention capability the victim has little chance, and even with it the odds are not good unless you can get them back under pressure in short order.

If I believe I can get the victim to effective help without killing myself in the process, that's what's going to happen.

But the first rule of rescue is "don't make two victims"......

__________________
"A venturesome minority will always be eager to get off on their own, and no obstacles should be placed in their path; let them take risks for Godsake, let them get lost, sunburnt, stranded, drowned, eaten by bears, buried alive under avalanches - that is the right and privilege of any free American."
http://www.denninger.net
http://www.diversunion.org/liability.htm - Fix the Diving Cert racket

silent running

Hello all, here's a question I've wondered about-
If a diver is having a O2 seizure, would the limit before brain damage occurs still be the same 4-5 minutes? I thought that the brain damage occurs because of a lack of O2. If the person is O2 toxic, wouldn't they have an excess of O2 in their blood, and thus have more time before BD occurs? Which would then give a bigger window to get them out of the water safely? -Andy

dteubner

Not at all - see my previous post. Hyoxia will not occur for quite a long time even if they don't start breathing again for whatever reason.

There is a thing called the Paul Bert effect which describes how you will eventually die (presumably of irrevesible brain effects) if the HYPERoxia doesn't go away.

Dave T

silent running

Hi dave, thanks for the clarification. I wasn't quite sure what you meant by the brain becoming hypoxic enough to kill you. I see what you meant now and it makes sens that brain damage will take a good while longer in the aftermath of an O2 hit than with other kinds of incapacitating seizures. -Andy

Mdemon

As Genesis has pointed out, if the person is breathing, or is likely to breathe when the fit ends, you're dealing with no more than an unconscious casualty and whatever deco the pair of you have. The casualty would seem to have less deco than you, since the gradient will be higher (the high O2) and when they start breathing they will be off-gassing quicker.

Which brings me back to my question above: are there more to these fits than just the two phases? Because if not, and their airway is protected (FFM/gag etc) then there is no reason to launch people to the surface and start getting over-excited.

So, rather than ripping masks off (?!!! btw! Why would you do that, ever?! Madness...) and dumping lead and adding DCS/CAGE to the equation, we should be focusing on maintaining the integrity of the casualty's loop/breathing system and airway.

This isn't a standard RD OC rescue, it's much more complex than that. And as pointed out above in several posts, raising someone is going to take time and is very labour-intensive. Why not put the effort into keeping a potential loop in place and controlling the guy's position in the water? You may be there a while until the CO2 builds up and the fit ends, but why on earth would you risk further, unnecessary damage to you or the victim by rocketing skywards if you are sure you can keep the airway open and loop/reg in place?

__________________
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dteubner

How can you be sure that you are maintaining their airway and that they are breathing adequately? It can be hard enough to do this in an ideal environment.

Even with a full face mask assessing the airway will be very difficult.

Holding an ordinary reg/DSV in an unconcious person's mouth so that they can breathe gas and not water for 30 minutes of deco seems like an unrealistic task to me.

Dave T

NeilHolden

For further info on this topic, here is what BR2806 (UK Military Diving Manual) has to say

BR 2806 Vol 2 (UK MILITARY DIVING MANUAL)

Art. 1321

c. Cerebral Oxygen Toxicity

(1) Symptoms and Signs. These are highly variable. Furthermore, there is no fixed O2 exposure at which toxicity becomes apparent. Instead, susceptibility varies both between individuals and within the same person from day to day. As a consequence, there is no cerebral equivalent of the UPTD. It is not unusual for the first sign of cerebral oxygen toxicity to be a grand mal convulsion. This generally occurs in two phases: First, there is a period of body rigidity - the ‘Tonic’ phase - which may last for up to a minute. It is dangerous to attempt to surface the casualty at this stage because spasm of the glottis and respiratory muscles will result in inadequate exhalation and may therefore provoke pulmonary barotrauma. The tonic phase is followed by the ‘Clonic’ phase during which the casualty undergoes true convulsions. This can last for widely varying periods of time. Symptoms which may precede the onset of a grand mal convulsion include: lip twitching; dizziness; nausea; ringing or roaring in the ears; tunnel vision; a choking sensation; difficulty breathing and tremor.

(2) Treatment. If a convulsion occurs underwater, the diver’s depth should be kept as constant as possible until at least the tonic phase of the convulsion subsides. He should then be returned to the surface. If a diver surfaces because of an oxygen convulsion or must be surfaced to prevent drowning, there is a risk of pulmonary barotrauma and the possibility of decompression illness should be considered in the event of subsequent neurological abnormalities. A neurological examination should be completed to exclude decompression illness. A period of confusion and
disorientation will follow a seizure. This must not be confused with neurological decompression illness.

(3) On reaching safety, remove the breathing apparatus and place the casualty in fresh air to recover. If there are any further convulsions, use sufficient restraint to prevent self-injury. Do not force the mouth open but, if necessary, keep the airway open once the convulsion has subsided (Fig 13-3), by positioning the head and neck gently into the ‘Sniffing the Morning Air position’.

(4) The casualty must be kept under observation by his fellow divers or in a sick bay for at least 12 hours; loss of memory almost invariably occurs, but this is normally limited to short-term memory and resolves quickly.

Note. Paradoxically, the symptoms of cerebral oxygen toxicity may be made transiently worse when the inspired PO2 falls. This is the so-called ‘Off Phenomenon’. Consequently the onset of symptoms or signs may be delayed by up to 5 minutes after leaving the water, coming off O2, or during a decompression stop where the partial pressure of O2 is reduced.