Equipment IPE and Regulator Adjustments

[Duke Dive Medicine]

Thanks for the insight. I’d be glad to share more details but I was not sure what would be pertinent and I didn’t want to over share info that may be irrelevant. If you don’t mind, what other factors should be considered? Or what questions should be asked. Thank you in advance for any information or guidance you can give me.

Has this ever happened to you before? How old are you, and do you have any history of heart failure, even mild? What was the water temperature, and how hard were you working under water when this happened?

Best regards,
DDM

 

[SubSoul]

Has this ever happened to you before? How old are you, and do you have any history of heart failure, even mild? What was the water temperature, and how hard were you working under water when this happened?

Best regards,
DDM

Hi. This has never happened before. I am a 45 year old female with no past medical history. Non-smoker, normal/lower end of normal weight, cardio exercise frequently and an active life style. I had a cardio work up last year for employment and no issues were detected. Wasn’t feeling off or ill the day of the dive.

After this incident I was evaluated at the hospital and although my troponin was high, my sodium low and my lactic acid high, they attributed this to “demand ischemia.” My BP and EKG were normal. No SOB, no chest pain…..nothing. My initial O2 sat was 93% but was 98% when I was discharged. All of the bloodwork trended back to normal levels and I was released 12 hours after I was admitted.

The water temp was 45 degrees but there was no drastic thermocline. I was wearing a dry suit with appropriate thermal base layers. I dive this site frequently.

Other than the typical task loading associated with descending (checking computers, making sure my bailout bottle is out of the way, putting air in my drysuit) there was little exertion. There was no current this day and the descent was slow due to a buddy needing extra time to equalize.

 

[Duke Dive Medicine]

Hi. This has never happened before. I am a 45 year old female with no past medical history. Non-smoker, normal/lower end of normal weight, cardio exercise frequently and an active life style. I had a cardio work up last year for employment and no issues were detected. Wasn’t feeling off or ill the day of the dive.

After this incident I was evaluated at the hospital and although my troponin was high, my sodium low and my lactic acid high, they attributed this to “demand ischemia.” My BP and EKG were normal. No SOB, no chest pain…..nothing. My initial O2 sat was 93% but was 98% when I was discharged. All of the bloodwork trended back to normal levels and I was released 12 hours after I was admitted.

The water temp was 45 degrees but there was no drastic thermocline. I was wearing a dry suit with appropriate thermal base layers. I dive this site frequently.

Other than the typical task loading associated with descending (checking computers, making sure my bailout bottle is out of the way, putting air in my drysuit) there was little exertion. There was no current this day and the descent was slow due to a buddy needing extra time to equalize.

That's interesting, thank you. Cold water is a risk factor for immersion pulmonary edema as it results in constriction of the blood vessels in the extremities, which directs even more blood into the vessels in the torso. The negative pressure/high work of breathing on inspiration may have been a factor as well. Did you have an echocardiogram done?

Best regards,
DDM

 

[SubSoul]

That's interesting, thank you. Cold water is a risk factor for immersion pulmonary edema as it results in constriction of the blood vessels in the extremities, which directs even more blood into the vessels in the torso. The negative pressure/high work of breathing on inspiration may have been a factor as well. Did you have an echocardiogram done?

Best regards,
DDM

I had one done last year as part of a work physical but they did not do one after this incident. I should have also added that this was our 2nd dive of the day after a 4 hour surface interval and the incident occurred approximately 4/5 minutes into the dive.

 

[CG43]

Hello Kendall Rainer

Do you know how to determine the relative impact on WoB from different cracking pressures? For example, if WoB of a regulator is 1.2" does tuning it to, say .8" reduce WoB by a 1/3? I'm sure it's not as simple as that, but wondering whether you know a way to impute the impact on Mitchell's 6g/l threshold gas density for differences in cracking pressure (holding all other factors like static lung load, etc., constant)?

I assume you wanted to write : For example , if the cracking pressureof a regulator is 1,2" does
tinning................. .
Michell's 6g/l threshold gas density is only a problem the OC diver has in his own airways .
ANSTI loop tests allready include air with highter density air the reg. has to work with .

Hello rsingler

As you suggested later, it's indeed quite complex. The change in WOB is more related to the total joules in the ANSTI loop, of which cracking effort is only the bottom right corner.

Are you shure ?
I guess a more negativ cracking pressure will shift the hole inhalation line down .
It's not a big deal for you to test this.

 

[Kendall Raine]

Hello Kendall Rainer


I assume you wanted to write : For example , if the cracking pressureof a regulator is 1,2" does
tinning................. .
Michell's 6g/l threshold gas density is only a problem the OC diver has in his own airways .
ANSTI loop tests allready include air with highter density air the reg. has to work with .

No. Tuning to .8" in order to lower WoB.

 

[Duke Dive Medicine]

I had one done last year as part of a work physical but they did not do one after this incident. I should have also added that this was our 2nd dive of the day after a 4 hour surface interval and the incident occurred approximately 4/5 minutes into the dive.

What were the results of the echo?

Best regards,
DDM

 

[SubSoul]

What were the results of the echo?

Best regards,
DDM

The results were normal. No defects or abnormalities noted.

 

[Duke Dive Medicine]

The results were normal. No defects or abnormalities noted.

This was a year ago though, correct? Before the incident of pulmonary edema?

You mentioned in your first post that you were cleared to dive by two different physicians after the event. What did the providers who cleared you think caused the pulmonary edema?

Best regards,
DDM

 

[SwimAway]

Isn't a regulator supposed to work perfectly fine at all depths at any setting of those little knobs and switches?

That is my experience with my regulators anyway. I adjust the knob and open/close the switch for my own "comfort", but I've gone entire dives with them both "closed" and never had a problem.