Recompression Chamber experience this past weekend

[CDNScubaMoose]

This past weekend (June 27-28th), I was in Tobermory, Ontario (Canada) for some fun diving as well as for some courses that I was team teaching (AOW, Bouyancy, and Night). The courses and other diving was scheduled for the weekend proper so when we arrived on the Friday we had made plans to take a tour of the local recompression chamber facility which included a "dive" in the chamber. Cost was $20 per person and we were limited to 6 participants (there was also a tender that came on the "dive" with us).

Prior to us getting there the technicians had pre-dove the main chamber since it takes more air and thus more time to take the main chamber to the depth. The plan was to have us cram into the air-lock and then take that to depth at which point we would move into the main chamber. Planned depth was maximum 135' and we were allowed to bring our computers in with us (they had a bucket of water to put them in).

They gave us a thurough breifing on the facility as well as health considerations that we should be aware of. We were also told that equializing inside the chamber was just as important as when diving but could be more difficult with it being likely we would have to equalize close to 30 times for the first 10'. After which we would descend faster but the equalizing would be more natural.

Step 1 - empty pockets of anything electronic (cell phones, watches), take off shoes and then cram into the air lock. I do mean - cram. I can't begin to explain how tight we were but I'm sure to an outsider looking in ... would get the imprssion of a bunch of college kids trying to see how many would fit in a VW bug.

Step 2 - descend to 10'. Lots of equalizing and we started to feel the first effect of Charles' Law. I'm sure everyone has noticed the increased temperature of their tanks if they get too fast of a fill. Well it apparently happens inside a chamber as well.

Step 3 - once everyone was comfortable at 10' we began the descent to 135'. Much quicker and equalizing was going good for everyone. I was concentrating on my equalizing and the effects of Charles Law was definitely present as everyone was sweating pretty good.

Step 4 - there wasn't a depth guage inside the air lock but best bet (based on how long it took us to get to that point and then to the rest of the way to 135') was around 90' the individual sitting directly across from me decided that my concentration on equalizing was rather humorous and he started to laugh. Well this set off a chain reaction and within 5 secs, we were all killing ourselves with our laughter. This started at 90' and was affecting all of us. Afterwards it amazed me to look back and see the effects.

Step 5 - at around 115' either the perception of or our actual voices changed. It sounded like we were a bunch of chipmunks on helium. Of course this didn't help to resolve the laughing and only made things worse.

Step 6 - when we got to 135', the door to the main chamber opened up and we were all able to crawl in (still laughing of course). Waiting there were several different tests for us to allow us to feel the effects of the narcosis (as if it wasn't apparent to us already). The tests include moving ball bearings with tweezers, combination locks and my personal favorite ... a Dr. Seuse book (Fox and Socks - I think it was Dr. Seuse). We spent 10 mins at this depth and laughing the entire time.

Step 7 - we started to ascend, they took us up at 60 fpm and our first stop was at 30' for 1 minute, follwed by 20' for 3 minutes, then 10' for 7 mins and finally 5' for 10 mins. I think this was the schedule - I may be mistaken. During the ascent we got to experience Charles' Law in the opposite direction with the temperature quickly dropping and actually below the dew point so we had extremely thick "fog" develop inside the chamber.

All in all, it was a very unique experience and it has made me rethink my belief that I don't start to suffer narcosis until 120' or so. I had experienced it occasionally shallower then that but nothing to the extent that I did through this route.

 

[AndyNZ]

I think a chamber visit is a must for any diver, it's a great experience.

Our local chamber does 'dry dives' to 50m, which are very funny. But there's a mine of information to be had as well. It never even crossed my mind that chambers have to be hydrostatically tested (every 5 years here, if I recall correctly) which must be a mammoth task! And talking about the treatments is a real eye opener - finding out what they do about equalisation issues with unconcious patients, and the ppO2 during a treatment (far in excess of 1.4ATA) is fascinating stuff.

 

[Diver0001]

I've made a chamber dive to a little over 30m (100ft) and my experience was very similar to the OP's.

If you want to log teh dive and/or see how "deep" you are then take a small bucket of water and put your computer in it.

I believe every serious diver should do a chamber dive at some point. The effects of narcosis is much easier to feel in the pot than in the water and it's a real eye opener.

R..

 

[toefa]

We are heading to the local chamber a week from today!! I have heard the effects of Narcosis dry are much more significant.

I just hope we get to do a few test like you did OP, like moving the ball bearings etc. I would really like to see how it effects my thought patterns.

Thanks for sharing.

 

[Diver0001]

I think a good game to try in the pot would be Yahtzee.

Get two people to play a game (and time it) before the dive and than play (and time it) at depth.

My bet is you'll be amazed.

R..

 

[shoredivr]

A few years ago I had the privilege of taking a chamber ride to 200 ft. The chamber (in Hamilton, Ontario) has two sections, one can go to 150 ft, the side I was in went to 200 ft. Half the group elected for the 150 side.
Those on the 200 side took a bucket of water and 6 different brands of dive computers. My job was to write down what each computer was recording. Interestingly, when fully at depth, one computer was 8 ft off. Also, my handwriting, which is illegible at the best of times, became tiny, yet easily readable....total run time for the dive was something like 185 minutes.

I took in a bottle of water to drink to help out with those initial equalization problems.

It was a great and very educational experience.

 

[Kevrumbo]

An invaluable experience, learning & practicing not only the Science & Art of Hyperbaric Medicine and Treatment of Dive Accidents, but actually seeing the Los Angeles County Medical Alert Center (MAC) System coordinate and integrate the various Departments on real recovery or rescue missions: all during my training over at Santa Catalina Island, offshore Southern California this past weekend [2006].

Although actual Chamber Treatments are in 60'/18m (Decompression Sickness/Syndrome) and 165'/50m (Arterial Gas Embolism) equivalent pressure, training runs are only done at 40'/12m with only two five minute oxygen periods, and one oxygen period at 20'/6m. The most fun & satisfying position on the Team is the inside Tender, where you would under direction, administer O2 therapy via demand-valve regulator to the patient and hopefully see the direct curative results of the treatment. Going down to depth inside the Chamber is kind of like sitting in your Scuba Tank (if you could!) during a fast fill: it gets very hot inside to 97deg F/37deg C very quickly! Conversely, on a wide open “fast” 10'/min (3m/min) ascent, the ambient environment can cool down just as fast and get a little chilly & foggy inside as the dew point is past (fun with Adiabatic Expansion first hand).

The trickiest and the position requiring the most mechanical dexterity is the Chamber Operator. You're moving & turning various handwheels & levers controlling inlet and exhaust valves; monitoring depth & pressure gauges of the supply gas gauges; keeping the patient at the right depth as well as bringing the Physician down to depth in an auxiliary Lock Chamber if needed to attend to the patient.

The most demanding is the Recorder. He is responsible for keeping track of treatment schedule; calling out the intervals for when the Tender is to administer O2 and Air Breaks to the patient; timing the descents & ascents; keeping track of all Total Dive Times, Decompression Times, Nitrogen Table uptake etc. for all personnel entering the Chamber to assist the Patient -and keeping a written record of all of this as it's happening on an elapsed timeline. This is the most difficult of the three positions on the team since you're setting up the entire profile of the "dive", and trying to record of the all various time segments involved in the treatment by monitoring/toggling a set of six stopwatch timers in front of you -and somehow officially logging it all down simultaneously on paper.

Finally, the Catalina Chamber is the only one able to administer immediate aid to a stricken diver covering an entire weekend period here in Southern California (Friday night to Sunday Evening): there is no back-up Chamber on the Los Angeles County Mainland that can be up and running as fast on any given weekend, or IMHO, on any given day 24/7. But talking to the Veteran Volunteer Crew training me, they would prefer having an asymptomatic diver come in the afternoon with a suspected case of DCS, rather than having that same diver later helicoptering back to Catalina from the mainland, with acute full-blown Type 1 & 2 Signs and Symptoms -at 3AM in the Morning. . .

Catalina Hyperbaric Chamber Home Page
National Board of Diving and Hyperbaric Medical Technology (USA)

 

[Spimon]

...finding out what they do about equalisation issues with unconcious patients, and...

How exactly does one equalise an unconscious patient?

 

[Scuds]

How exactly does one equalise an unconscious patient?

Very carefully, of course.

 

[qrpc]

How exactly does one equalise an unconscious patient?

I read somewhere that one of the medical team stays in the chamber with
the patient and if, needed, they can make a small puncture the patient's
ear-drum. I imagine that sort of thing is a last resort, but compared to
acute DCS, I doubt the patient would complain.