Water entry with regulator in mouth can cause embolism?

[RubberDucky]

By the way, my 1994 PADI Open Water Diver Manual addresses, on p. 150, the issue of "choking on inhaled water" by suggesting one "hold the regulator or snorkel in place and cough through it" and adds that "swallowing sometimes helps relieve choking, too."

My mistake - it is in fact mentioned in mine as well (p. 82). I'll be reviewing the book again before my next diving excursion (which will start out with the refresher course!), it's been toooooo long

I've had my own experience with a partial laryngospasm, so I respect the danger and take a few simple precautions to reduce it.

Aside from what you already mentioned about the precautions in a previous post:

my regulator is always in my mouth when I'm at any risk of taking a shot of water down the wrong pipe!

and aside from what is taught about using your tongue as a splash guard when purging your regulator, I'd be interested in learning about any other precautions you (or anyone) take.

In regards to the embolism at the surface story, that's a very interesting read. That must be one of the worst cases of bad luck in the history of bad luck. Seriously, who could ever see that comin'.. jeez.

 

[Thalassamania]

Either urban legend, or the wild imaginations of a non-diver who reads a lot yet has no training or experience.

Never heard of this happening, ever, anywhere, anytime.

It did give me a good chuckle though, as I found it rather funny.

Really? I can see why you limit yourself to impressing on your students a need for a depth of knowledge, it might help to gain that yourself before you run off at the mouth and question others' veracity.

In regards to the embolism at the surface story, that's a very interesting read. That must be one of the worst cases of bad luck in the history of bad luck. Seriously, who could ever see that comin'.. jeez.

I didn't what to bring this accident into the discussion because it is a Loooooong way away from recreational diving. But please understand, this was not bad luck, it was a case of the German Habitat Engineer (Joe) being complacent and overly confident in his own skills and not following protocol. This was a known potential problem with any habitat that has an "energy buoy" and was (is) discussed during all mission briefings that do in-habitat decompression followed by a no-D ascent to the surface (Agir, PRINUL, Aquarius, etc.)

If you read your way through all the NUADC reports (I wish I could remember even what) in RUBICON you'll find some similar recreational cases.

 

[dave4868]

....and aside from what is taught about using your tongue as a splash guard when purging your regulator, I'd be interested in learning about any other precautions you (or anyone) take.

Coughing or puking while under water should always be done through the regulator because the reflexive inhalation after the ejection will happen very quickly.

Other precautions come from just using your common sense in judging what situations warrant keeping the regulator (or snorkel) in one's mouth.

Examples of situations might include slippery shore entries, being on the surface in rough seas, surf or current, standing on a pitching boat's ladder, providing support to a struggling diver on the surface, etc.

It's tempting to try to look confident and go without the breathing apparatus during such situations, but such vanity could be costly, IMO.

I used to think it was easy to just time my breaths with the whitecaps while waiting for the boat to pick me up, that is, until I got the top of a wave down my throat! It triggered a massive coughing fit! Who knows what may have happened if I got another dose right then! Now, I don't mind appearing overly cautious with the snorkel in my mouth, since I'm breathing easily no matter what splashes in my face!

In regards to the embolism at the surface story, that's a very interesting read. That must be one of the worst cases of bad luck in the history of bad luck. Seriously, who could ever see that comin'.. jeez.

Accident reports can be very instructive, especially when one can see oneself in the same situation.

Dave C

 

[Melicertes]

You may find interesting the following report by Howard W. Pollock entitled:

A CLASSIC CASE OF DIVER AIR EMBOLISM AT THE SURFACE FROM HIGH WAVE ACTION

http://archive.rubicon-foundation.org/6120

According to the article:
1. "The accident occurred following a 3 day saturation dive..."
2. "a normal ascent, at least until the dive team was about 15' to 18' from the turbulent surface..."
3. "10' to 12' waves were breaking against structures and equipment on the surface..."
4. "He was then towed on his back by two support divers, unisuit inflated, regulator in his mouth, with his head out of the water. Although he was virtually incapacitated on the return to the support vessel, there was an occasion when some of the seas washed over causing Joe's mouthpiece (regulator) to come out, and he personally replaced it with his right hand and held it in place momentarily: but, then both hand and mouthpiece fell away. One rescue diver later commented, 'his eyes were open, although I can't recall seeing him blink as the water passed across his face.' Another diver reported that when Joe was being towed a white frothy foam was bubbling from his mouth."

Point 1 tells me that this guy had been under other than usual conditions that we normally would associate with recreational divers just prior to the embolism. Even though he may have been put through the decompression protocols that were considered applicable in the mid-seventies, saturation diving separates this case dramatically from the normal conditions expected with dives done by recreational divers. I wonder if the embolism didn't have more to do with his saturation activities during the prior three days and perhaps even with the irregular ascent during the last couple of feet to the surface than with the fact that he had his reg in his mouth at the surface when he embolized.

Points 2 and 3 seem to imply that the ascent rate followed by the dive team during the last 18' to 15' was not normal and most likely accelerated and even made worse by the 10' to 12' waves breaking at the surface. I have personally experienced what it feels like to do a fun roller coaster ride at the surface with 8' to 10' swells; thinking about 10' 12' breaking waves though must have been seriously daunting. These are not conditions that I think your average vacation diver will most likely ever encounter when they sign up for the morning dive roster at Popeye's Dive charter.

Finally, point 4 seems to describe the events at the time the embolism occurred. The diver was being towed by the support divers at the surface with his unisuit fully inflated and his head out of the water. He even replaced his regulator himself when it was washed out of his mouth by some water. This makes me think that he was conscious enough at the time and since one support diver mentioned that he could see Joe's open eyes but could not recall if he saw him blink as the water washed over his face it leads me to think they were not in a Maytag spin cycle when Joe embolized but that the waters were rough enough to wash aggresively over his face.

In this case it does not seem as if Joe held his breath and resurfaced from a depth that could have caused lung over-expansion injury or anything similar that could have caused him to embolize. It seems more likely to me that he may have embolized due to sudden reduction of ambient pressure as they surfaced the final 15' to 18' to the surface which was probably made worse by the huge breaking waves. Having just completed a saturation dive just prior to the event doesn't help either. Without more information I suspect that these were extraordinary circumstances that most recreational divers would never see so I see very little that suggests that anything in this article applies to the OP's thread here.

 

[Thalassamania]

According to the article:
1. "The accident occurred following a 3 day saturation dive..."
2. "a normal ascent, at least until the dive team was about 15' to 18' from the turbulent surface..."
3. "10' to 12' waves were breaking against structures and equipment on the surface..."
4. "He was then towed on his back by two support divers, unisuit inflated, regulator in his mouth, with his head out of the water. Although he was virtually incapacitated on the return to the support vessel, there was an occasion when some of the seas washed over causing Joe's mouthpiece (regulator) to come out, and he personally replaced it with his right hand and held it in place momentarily: but, then both hand and mouthpiece fell away. One rescue diver later commented, 'his eyes were open, although I can't recall seeing him blink as the water passed across his face.' Another diver reported that when Joe was being towed a white frothy foam was bubbling from his mouth."

Point 1 tells me that this guy had been under other than usual conditions that we normally would associate with recreational divers just prior to the embolism. Even though he may have been put through the decompression protocols that were considered applicable in the mid-seventies, saturation diving separates this case dramatically from the normal conditions expected with dives done by recreational divers. I wonder if the embolism didn't have more to do with his saturation activities during the prior three days and perhaps even with the irregular ascent during the last couple of feet to the surface than with the fact that he had his reg in his mouth at the surface when he embolized.

I am intimately familar with the decompression that was conducted inside the habitat, it was complete and just prior to their repressurization, reimmersion and ascent the team was at 1 ATA.

Points 2 and 3 seem to imply that the ascent rate followed by the dive team during the last 18' to 15' was not normal and most likely accelerated and even made worse by the 10' to 12' waves breaking at the surface. I have personally experienced what it feels like to do a fun roller coaster ride at the surface with 8' to 10' swells; thinking about 10' 12' breaking waves though must have been seriously daunting. These are not conditions that I think your average vacation diver will most likely ever encounter when they sign up for the morning dive roster at Popeye's Dive charter.

The sea conditions on that day were very difficult, but the crew recovery operation was deemed doable.

Finally, point 4 seems to describe the events at the time the embolism occurred. The diver was being towed by the support divers at the surface with his unisuit fully inflated and his head out of the water. He even replaced his regulator himself when it was washed out of his mouth by some water. This makes me think that he was conscious enough at the time and since one support diver mentioned that he could see Joe's open eyes but could not recall if he saw him blink as the water washed over his face it leads me to think they were not in a Maytag spin cycle when Joe embolized but that the waters were rough enough to wash aggresively over his face.

In water 170 feet deep there is no "spin cycle" even when the waves are "breaking." It is a very different kind of break, not one where the wave reforms and builds and then the top tumbles off as the bottom is slowed, but where the top of a creast is blown by wind off the bottom of the wave.

In this case it does not seem as if Joe held his breath and resurfaced from a depth that could have caused lung over-expansion injury or anything similar that could have caused him to embolize. It seems more likely to me that he may have embolized due to sudden reduction of ambient pressure as they surfaced the final 15' to 18' to the surface which was probably made worse by the huge breaking waves. Having just completed a saturation dive just prior to the event doesn't help either. Without more information I suspect that these were extraordinary circumstances that most recreational divers would never see so I see very little that suggests that anything in this article applies to the OP's thread here.

The Habitat Engineer was holding onto an pipe that was fixed with respect to the bottom whilst waves of fifteen or so feet passed over him rapidly, the saturation dive that been completed was complete irrelevant in that the they had fully decompressed in the bunk room and were at 1 ATA less that five minutes before the accident.

 

[pt40fathoms]

before you run off at the mouth and question others' veracity.

Running off at the mouth? Question others' veracity?

I see nowhere in my post where this was evident, and warranted such a visceral retort.

Having a bad day are we?

 

[dave4868]

Without more information I suspect that these were extraordinary circumstances that most recreational divers would never see so I see very little that suggests that anything in this article applies to the OP's thread here.

IMHO, Pollock's report has numerous facets that can be applied to this thread's discussion.

Our main discussion has been about the potential that one might suffer arterial gas embolism near the surface related to entering the water with a regulator in one's mouth. It's also been about whether it would be prudent to take preventive measures.

Applicable insights can be gained from the report:

• Arterial gas embolism can occur with as little as a 4' change of depth under certain conditions (full inhalation held)
• A tiny amount of water can cause laryngospasm (breath-holding reflex) and result in constriction of the air flow and trapping the expanding gas in the lungs
• Near-surface depth (and pressure) changes can occur in unusual ways, such as during intermittent dunking
• Experienced divers can make mistaken judgments under adverse situations and/or stress or injury

In our discussion, these insights could lead one to:

• Use more care during high-drop entries, especially in rough seas (hold the regulator firmly in one's mouth, breathe normally)
• Consider alternatives and their risks

Other discussions may arise from this such as:

• What are the risks of anchoring oneself to a mooring line in rough seas?
• What are the risks of being on a pitching boat's ladder and being dunked repeatedly ?
• What are the risks of trying to manage extraneous gear under adverse conditions?

For some people, I think Pollock's report may actually provide some excellent "food for thought".

It did for me.

Dave C

 

[Melicertes]

I am intimately familar with the decompression that was conducted inside the habitat, it was complete and just prior to their repressurization, reimmersion and ascent the team was at 1 ATA.
The sea conditions on that day were very difficult, but the crew recovery operation was deemed doable.
In water 170 feet deep there is no "spin cycle" even when the waves are "breaking." It is a very different kind of break, not one where the wave reforms and builds and then the top tumbles off as the bottom is slowed, but where the top of a creast is blown by wind off the bottom of the wave.
The Habitat Engineer was holding onto an pipe that was fixed with respect to the bottom whilst waves of fifteen or so feet passed over him rapidly, the saturation dive that been completed was complete irrelevant in that the they had fully decompressed in the bunk room and were at 1 ATA less that five minutes before the accident.

Fair enough. I wasn't there and I don't proclaim to be entirely clued up on this case specifically, or any other case for that matter. I'm just going on how I interpreted what was in the article after a brief read. Those conditions must have been hairy to say the least, that much I agree with you. Lots of things go wrong in hairy situations, even when they appear incredulous. I still do not think that the average vacation diver will ever likely see conditions like that but if it lends support to the idea that even minimal submersion while holding a breath could lead to embolism, well I'm not going to say impossible, or b.s. I'll concede that it may be possible and I will even go as far as to say that I believe that under some pretty narrow and specific circumstances it might even be probable. However, to conclude that just because something bad has happened once, or twice, or three times (there must surely be more similar cases as this one) that we therefore should not ever do something, e.g. enter with our regs in our mouths, does not seem reasonable to me. If we were to stop doing everything we do every day just because somewhere something has gone wrong with someone doing it, we'd probably never do anything, and even then we might be at risk of something bad happening to us.

I know of a case where a student embolized in a pool during confined water training, so I am not saying you have to be at least 15' down before there's a risk. Every time I enter the water in my drysuit I recognize the squeeze I feel on my legs because of the pressure exerted at that shallow depth already, so possible, you bet, probable if entering the right way with some precautions? Hmmm...unlikely methinks.

So, to make a long story short, I think it is fair to say that when entering the water, keep your BCD reasonably inflated, break the depth penetration of your plunge by keeping your legs splayed apart in the giant stride stance (unless you're doing a backward roll the way I'm used to, but then again keeping your legs splayed apart might make for some pretty funny laughs then too ;o), keep your reg in your mouth (I may be mistaken but most students are probably taught this way as far as I know,) don't ever hold your breath, and you'll be just fine.

 

[RonFrank]

Holding one's breath while ascending can cause an embolism. That has zero to do with entering the water with a regulator in ones mouth. One would have to be breathing on the way down, descend a goodly ways, and then holding ones breath on the way back up to result in an embolism.

That is hardly the same thing as what is suggested by the OP. EVERYONE I've ever dove with enters the water with the reg in their mouth. If you don't... well then you can not breath UW which defeats the point of all that equipment on your back!

I once started an ascent without my regulator in my mouth, I did not get very deep!

That main point is always BREATH! If you do that, you are at least halfway there! The other thing to keep in mind is controlled ascents. In this case either a diver jumps off the boat, and starts their ascent immediately..... OR they inflate their BC part way, and never goes below a couple of feet before rising back to the surface. In either case, the bottom line is as long as one continues breathing..all is well.

 

[Melicertes]

For some people, I think Pollock's report may actually provide some excellent "food for thought".

It did for me.

Dave C

I hear you. It's certainly food for thought. Am I going to change the way I do things because I read this report? Unlikely; but it is interesting, albeit somewhat sad, to read about what happened.