Performing a CESA After Exhale

[Storker]

Grab a lungful of whatever's left in your BCD.

If you have any other option, that's probably bad advice.

Mike Firth - Diver - Aspergillosis Patients and Carers

 

[TMHeimer]

I think people are missing his point. He’s not talking about running out of “Air” before reaching the surface, he’s talking about the requirement of exhaling during ascent to prevent an over-expansion injury.

I’ll give a shot at the answer. If your lungs are truly empty, they can’t expand upon ascent, and therefore exhaling is unnecessary. In reality, some air will remain and can expand, and therefore upon ascent you should try to exhale as more gas “becomes available”. As someone else stated, the gas in your tank also expands, and you often get a breath there as well to help during ascent. I think this is why “blow and go” isn’t recommended; even if you think your lungs are empty, air can still expand resulting in over-expansion injuries.

I’ve never done a “real” CESA from more than about 4 meters, so maybe I’m a little off base here and would like some verification of my answers.

Agree. A point we all probably know is that keeping your airway open is what counts, regardless of what air is in your lungs. Exhaling only "confirms" that it is open, and saying "Ahhhh…….." only confirms to the instructor during a class that it is open. I do all of the above anyway.

 

[Norrm]

If you have any other option, that's probably bad advice

That was a very rare situation- I don't recall ever hearing about another one. If someone is concerned about going OOA then they might want to practice regular disinfection of the BCD bladder or at least periodically do a REALLY good rinse by removing 2 dump valves and running freshwater through it. (or run water directly into the BCD vent using a garden hose adapter.

 

[TMHeimer]

That was a very rare situation- I don't recall ever hearing about another one. If someone is concerned about going OOA then they might want to practice regular disinfection of the BCD bladder or at least periodically do a REALLY good rinse by removing 2 dump valves and running freshwater through it. (or run water directly into the BCD vent using a garden hose adapter.

After each dive day I rinse inside the BC with baby shampoo & tons of fresh water (AFTER dumping out as much salt water as humanly possible). I found that this was not discussed very often in OW courses or on SB. I don't know how good this is in preventing infections from breathing BC air--can't hurt.

 

[Griffo]

Just try to hum on the way up, it will keep your glottis open and any residual air will escape. Just like a cesa with full lungs.

 

[decompression]

I sincerely wish the CESA was eliminated from all training agencies that still teach it.........for a multitude of reasons......not least of which the discussion usually brings up the “breathe from your BCD” silliness. Much better off teaching ways to avoid the scenario in the first place.

 

[TMHeimer]

I sincerely wish the CESA was eliminated from all training agencies that still teach it.........for a multitude of reasons......not least of which the discussion usually brings up the “breathe from your BCD” silliness. Much better off teaching ways to avoid the scenario in the first place.

I had my SPG needle get stuck on 1000 psi once (it was busted, needed a new one). I noticed it wasn't going lower, so I ended the dive. It was like, a 20' dive tops. If I hadn't noticed it, I may have gone OOA and would've been thankful that I could do a CESA, having practiced it.
Perhaps it would be best to at least keep the horizontal CESA in the pool drill, so the instructor doesn't have to go up & down all those times with students in OW. At least students would be shown what it is and then could practice it on their own after gaining some diving experience.

 

[boulderjohn]

I realize this is an old thrad, but I could not resist making a couple comments.

As someone else stated, the gas in your tank also expands, and you often get a breath there as well to help during ascent.

The gas in your tank will not expand because it is an inflexible container that is not affected by ambient pressure. What will be affected is the regulator's first stage, which reduces the tank's pressure to roughly 140 PSI more than ambient pressure. If the tank pressure gets too low, it can no longer do that, and it becomes harder and harder to breathe. As you ascend, ambient pressure decreases, so the regulator will once again be able to deliver air to you.

That last point is important for the purpose of this thread. Not only will you get more air from the tank as you ascend, you should also get a warning that the tank is getting low on air, so you should not just run out of air at the end of an exhale. I regularly have to drive over a mountain pass not long after diving, and I often breathe what is left in my oxygen bottle as I drive as a safety measure. On the days that I actually finish off a bottle, I can tell I am getting to the end with 5-6 breaths to go.

 

[decompression]

I had my SPG needle get stuck on 1000 psi once (it was busted, needed a new one). I noticed it wasn't going lower, so I ended the dive. It was like, a 20' dive tops. If I hadn't noticed it, I may have gone OOA and would've been thankful that I could do a CESA, having practiced it.
Perhaps it would be best to at least keep the horizontal CESA in the pool drill, so the instructor doesn't have to go up & down all those times with students in OW. At least students would be shown what it is and then could practice it on their own after gaining some diving experience.

Understood but I’d rather focus on situational awareness.......as per your example.....where was your teammate?

 

[TMHeimer]

Understood but I’d rather focus on situational awareness.......as per your example.....where was your teammate?

You know this is the Solo forum, no?
Agree completely on focusing on situational awareness. Doesn't mean knowing how to do a CESA is pointless. You just may slip up someday--we are all capable of that. I read that the most likely candidates for accidents are new divers and very experienced ones (due to becoming complacent). You can have great situational awareness and still have CESA in your tool box. What can it hurt?