Time to recover SAC after CO2 hit

i want to say something but i best not ,

but looking at this thread make,s me shake my head at ccr divers talking some right bollox ,

have none of you ever been oc divers lol if so start there, why what & how , fook the loop your all shiting on about ,

understan it oc wise then add in your loop , and all that go,s with said LOOP


ps

once you understand co2 in oc divers , you will then think why the fook do i dive nitrox in my rebreather , lol
 
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AlexBerger said:
so what causes co2 in your loop? or what causes inadequate ventilation?
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Rising CO2 on the inhale side would be because of bypass or a failed scrubber. Rising CO2 on the exhale side can be anything as any cause, retention or otherwise, will increase CO2 levels here.

Bypass, scrubber failure or bad gas would more properly be called CO2 poisoning. Even if you breathe optimally you will not get rid of it.

In retention your level of ventilation compared to current CO2 production is insufficient and optimized ventilation will reduce or remove the problem
 
Johan Isaksson said:
In retention your level of ventilation compared to current CO2 production is insufficient and optimized ventilation will reduce or remove the problem
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It is quite possible to have a CO2 hit on OC. Trying to ventilate too hard will cause the bronchi to collapse and the gas in the aveoli will not exchange. That's why trying to plan for a 100L/min ventilation rate is pointless. If you are breathing that hard and fast you are going to die even if you have unlimited OC bailout gas.

This explains it for you. Starting around minute 20 but watch the whole thing.
https://www.youtube.com/watch?v=GW1yVFF_FK4
 
rjack said:
It is quite possible to have a CO2 hit on OC. Trying to ventilate too hard will cause the bronchi to collapse and the gas in the aveoli will not exchange. That's why trying to plan for a 100L/min ventilation rate is pointless. If you are breathing that hard and fast you are going to die even if you have unlimited OC bailout gas.

This explains it for you. Starting around minute 20 but watch the whole thing.
https://www.youtube.com/watch?v=GW1yVFF_FK4
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I'm a specialist in respiratory medicine and fully aware how ventilation works, note the use of "optimized" rather than "increased" ventilation :)

I'm trying to simplify it somewhat to get the point across of the different mechanisms between hypercapnia caused by inhalation of CO2 rich gas and the more common event in rebreather diving when work of breathing, dead space, breathing patterns etc. lead to a build up of CO2 in the body that will not show up on an inhale side CO2 monitor.
 
(1) Retention of carbon dioxide during working dives at moderate depth is a definite reality.

(2) Only when the breathing medium is a helium-oxygen mixture is an increase in body carbon dioxide
tension absent or small.

(3) Although increased breathing resistance and dead space both favor carbon dioxide retention, keeping
these factors to a practical minimum does not eliminate the problem.

(4) Some individuals are much more likely to develop high carbon dioxide tensions than others, but all
individuals show a tendency in this direction especially when breathing a nitrogen-oxygen mixture.
There is no sharp dividing line between "retainers" and "normals."

(5) The most effective method of minimizing the complications caused by carbon dioxide retention is to
use helium-oxygen mixtures for "mixed gas" dives

read number 5 once a gain , ask your self do you know what the complications are, and will adding a new gizmo cover them all . answer should be NO will if feek ,


https://www.google.com/url?sa=t&rct...im.pdf&usg=AFQjCNHlM8-mlA-naUeKoQtzWewi4ppXSg
 
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AlexBerger said:
wow ATB mark is the superman he can breath co2 and not retain it amazing!!!!!!!
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Man your missing the point by such a large margin it worries me. You seem to totaly ignore the fact the scrubber has little or nothing to do with retained C02 issues and that retained C02 or non scruber related unit failure are the most likley issue on any unit where the diver is not pushing the scrubber.

Yes you me and the dog can breath C02 without retaining it

The problem is C02 trigers the bodies responce to breath.

More C02? Faster and more urgent breathing rate which will eventiualy cause the avilo to colaps and THEN and only then will your abuility to exhale C02 is reduced and you will be in a period of C02 retention

Dr Simon Mitchell did an excelent presentation on this in responce to the death of Dave Shaw from retained C02 as a result of poor asembly of his Mk15.5 CCR and dense gas.

He died of C02 related issues but his scrubber (which was 15mins old from new) was just fine

You really need to look it up and get a better understanding of C02 related issues and diveing
 
rjack said:
It is quite possible to have a CO2 hit on OC. Trying to ventilate too hard will cause the bronchi to collapse and the gas in the aveoli will not exchange. That's why trying to plan for a 100L/min ventilation rate is pointless. If you are breathing that hard and fast you are going to die even if you have unlimited OC bailout gas.

This explains it for you. Starting around minute 20 but watch the whole thing.
https://www.youtube.com/watch?v=GW1yVFF_FK4
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lol

when i first went from 70m air diving to 70m mixgas diving my sac all most Dubbled , so id say i had a good bit of retention on the treacle toffee , but no co2 hit ,
most iv even seen oc is someone with a headache,
 
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matt said:
I've no longer any idea what you are going on about. Sorry.

Hypercapnia and CO2 retention are the same thing. I put what I thought in #59.
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Hypercapnia is mearly the medical term for the efect of both retained C02 related issues and scruber failure C02 related issues

The medical term for the bodies reaction to C02 poisening is not the point of discussion.

The point is:

The cause of a scrber related C02 hit is overworking or bad packing of the scrubber. This can be detected by scruber monitors and existing C02 detectors

The cause of retained C02 is work of breathing or gas friction due to depth related increse in gas density

BOTH will result in the condition Hypercapnia

Retained C02 related Hypercapnia can not be detected by a C02 moniter. Your retaining it. QED its not in the loop to detect

I am running out of ways to try and clarifie this very basic principle
 
I might as well throw something else into the equation. :lol:

If you are breathing shallow and not exhaling fully, you will also tend to retain CO2. This can happen on OC or CC regardless of workload or WOB.
 
DSix36 said:
I might as well throw something else into the equation. :lol:

If you are breathing shallow and not exhaling fully, you will also tend to retain CO2. This can happen on OC or CC regardless of workload or WOB.
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read my link , save your arm :lol:


ps
i like to save me throwing arm as its the same arm i pull my self round the room with , :haha:
 
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DSix36 said:
I might as well throw something else into the equation. :lol:

If you are breathing shallow and not exhaling fully, you will also tend to retain CO2. This can happen on OC or CC regardless of workload or WOB.
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bit llike teaching Minimum loop , for good buoyancy and not saying feek all about co2 and inadequate ventilation lol

let me think piss 10 bar of gass away or run min loop help retain co2 , maybe have a o2 hit later ,


lol fook it just buy all the gizmo,s no need to help your self be safe , or even know why your not safe , or when you are probably safe ,

i can see why deas and brad can have a good old time with the WOB format , on the Shallow water blackout unit they sell :lol:
 
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Mr fish said:
bit llike teaching Minimum loop , for good buoyancy and not saying feek all about co2 and inadequate ventilation lol

let me think piss 10 bar of gass away or run min loop help retain co2 , maybe have a o2 hit later ,


lol fook it just buy all the gizmo,s no need to help your self be safe , or even know why your not safe , or when you are probably safe ,

i can see why deas and brad can have a good old time with the WOB format , on the Shallow water blackout unit they sell :lol:
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lol i am out of here
 
Mark Chase said:
Oi, tell us what you thaught of Dr Mitchels presentation on retained C02 first

Note there wasn't a scrubber in sight

ATB
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well he did talk about one for 10sec and then he went on about retaining co2 from elswere.so you are right i am wrong but thats not why i am out its cos mr. fish started to talk about deas and brad
 
AlexBerger said:
well he did talk about one for 10sec and then he went on about retaining co2 from elswere.so you are right i am wrong but thats not why i am out its cos mr. fish started to talk about deas and brad
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I can edit that if its not to your liking l:hehehm:
 
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