anyone want the truth and science on inwater recompression? It's incredibly effective

[Kevrumbo]

We carry T bottles and have an AL80 full waiting normally with a reg on.As our exposure runs from 5-7 dives per day @ 100' to 5-7 @ 180' X 5-7 days and using profiles that are basically square and on Cochran or Orca computers DCS is always a possibility.

What we do is the result of 10s of thousands of dives over many years by a few dozen guys.I am a new guy with over 5000 dives and full tri-mix cert almost 15 years ago,4000 of which are commercial spearfishing.Some guys have 30-40+ years at that rate.One guy has a boat that has been fishing since 1974.We have learned .

Facemasks don't work in current,nor rigging other than a heavily weighted downline.

Get in at the first sign of DCS and not just soreness from work

As our BTs are short,there is no need for long hangs to completely unbend

30' doesn't work very often

Hop in on 02 soon if you blow deco for any reason(14' tiger etc..)

Even a guy flopping on the deck or partially paralyzed can be unbent,given they can keep a reg in their mouth while someone swims them down(where symptoms will sometimes immediately start improving)

1 of our anecdotes is worth 15 people online parroting what they read or opine in regards to spearfishing,diving,deco,seamanship,boat handling,fish populations etc....

I do appreciate the concern that lies behind the advice and references.

The kind of diving that's best applicable for the UTD IWR contingency profile is non-commercial/non-professional/non-military, "sport recreational" technical diving with mandatory decompression, with no more than two deep deco dives per day for a week or more, often in a remote overseas location. Most DCS symptoms will be of a type I variant -acute pain only limb/joint- which manifest either immediately upon surfacing or latently over several hours, especially after several days of Deep Air dives because of slow tissue inert N2 loading.

29June to 11July 2013: On Day 8 of scheduled 9 dive days of my own experience last year at Bikini Atoll -and even though the liveaboard (M/V Windward) had a Recompression Chamber onboard- I still elected to perform the UTD/modified Australian IWR protocol after surfacing with upper right arm/shoulder pain. On a scale of 1 to 10 with initial pain of "10+", descending to 9 meters immediately relieved the pain to a dull "4", and upon completing the IWR profile & surfacing, an achy "2 to 3". I was administered an IV drip -Plasmalyte and Caldolor (intravenous Ibuprofen -Thank You Simon Mitchell, M.D. Ph.d), with additional surface O2 breathing for an hour. Took four days off and resumed diving later for another week's trip to Truk Lagoon, with augmented O2 deco time to my nominal profile to ensure slow tissue N2 off-gassing.

(Typical dive profiles are 45m to 63m deep for 50 minute Bottom Time with Total Run Time over 160 minutes; then a three-and-a-half hour SIT; and then the second and last dive 24m to 39m deep for 70 min BT and TRT of over 100 min. Bottom mixes are Air or 20/20 Trimix with Eanx50 and O2 for deco gases).

 

[100days-a-year]

Glad you were OK.We normally return to diving the next day although some dive the next round.

Why may I ask did you chose the IWR?In that position I would likely prefer the chamber.

We do what we do out of necessity for the most part,and to keep the rest of the crew working.We work on production ie no fish=no money.

I thought we were on the limit of N2 exposure til I read the Miskito Indian lobster divers story that has floated on the net.

Same for 02.There is a book by Vane Ivanovic which chronicles the use of early 02 rebreathers,worth a read for every tech diver to balance out the hysterical "you're all gonna die""you must be a genius/machoman like me to do this""cause I,we,whomever says so"that will eventually find it's way into just about every forum discussion of most aspects of tech diving.From suicide clips to BWOD to which algorithm to use

 

[Michael Guerrero]

IANTD has an IWR class too.

 

[Kevrumbo]

Glad you were OK.We normally return to diving the next day although some dive the next round.

Why may I ask did you chose the IWR?In that position I would likely prefer the chamber.

We do what we do out of necessity for the most part,and to keep the rest of the crew working.We work on production ie no fish=no money.

I thought we were on the limit of N2 exposure til I read the Miskito Indian lobster divers story that has floated on the net.

Same for 02.There is a book by Vane Ivanovic which chronicles the use of early 02 rebreathers,worth a read for every tech diver to balance out the hysterical "you're all gonna die""you must be a genius/machoman like me to do this""cause I,we,whomever says so"that will eventually find it's way into just about every forum discussion of most aspects of tech diving.From suicide clips to BWOD to which algorithm to use

I chose IWR because we were informed before the start of the charter that DAN would not pay for the treatment in the Recompression Chamber aboard M/V Windward --I would have had to wait -in acute pain!!!- while an emergency evacuation flight was arranged through US Coast Guard to fly into Bikini Island to fly me back to Kwajalein or Honolulu. Also, I didn't want to tie-up the onboard Chamber for my "simple" type I DCS event, just in case someone else came up with a more serious type II DCS/AGE hit. . .

 

[Centrals]

I chose IWR because we were informed before the start of the charter that DAN would not pay for the treatment in the Recompression Chamber aboard M/V Windward -- .

So the on-board chamber is NOT FREE!!!!!
I am pretty sure the on-board chamber on one of the well-known tec liveaboard boat in SE Asia is FREE. And we all know which boat it is.

 

[bakodiver391]

We performed two chamber treatments aboard the Windward this year and it was indeed free. DAN has been hesitant to allow treatment onboard because they have not certified the chamber but in this case the risk was warranted, and the outcome was very positive. We have different physicians onboard at different times who have differing protocols, so we follow their instructions, but generally speaking, a chamber ride means your diving vacation is over, but a bit of IWR does not rule out further diving after a 24 hour break. There is a lot of good information in this thread and a lot of funny stuff as well. If you do deep, long, decompression diving, you are eventually going to take a hit, it's just a matter of when. What you do at that point, and how well prepared you are, may well determine how the rest of your life unfolds. I don't want to be a cripple, so I know I will be grabbing a tank of O2 and heading back down. It's not rocket science.

 

[Kevrumbo]

We performed two chamber treatments aboard the Windward this year and it was indeed free. DAN has been hesitant to allow treatment onboard because they have not certified the chamber but in this case the risk was warranted, and the outcome was very positive. We have different physicians onboard at different times who have differing protocols, so we follow their instructions, but generally speaking, a chamber ride means your diving vacation is over, but a bit of IWR does not rule out further diving after a 24 hour break. There is a lot of good information in this thread and a lot of funny stuff as well. If you do deep, long, decompression diving, you are eventually going to take a hit, it's just a matter of when. What you do at that point, and how well prepared you are, may well determine how the rest of your life unfolds. I don't want to be a cripple, so I know I will be grabbing a tank of O2 and heading back down. It's not rocket science.

Hey BK good to hear from you! Hope the treatments were routine & glad the outcome went well. Not good to hear that DAN still hasn't certified the chamber -and although y'all performed the treatments "pro bono"- I know that timely DAN reimbursement for Hyperbaric Oxygen Therapy without all the bureaucratic red tape is great to have and necessary to cover stand-by & operation costs.

And if daylight, weather & sea conditions warrant it, I believe it's a good first option to try IWR with the onboard Chamber standing by, especially for signs/symptoms like my case: simple type I DCS acute limb pain only, with history of consecutive deep dive days requiring decompression profiles with 50% & O2 while using bottom mixes with high FN2 content such as Air. Those slow tissues load up, and all it takes is a muscle strain on ascent to your deco stops (i.e. holding onto the upline/shotline; manipulating stage tanks; scootering around with your steering arm working hard etc), and then you will have bubbles precipitating & impinging on muscular-skeletal tissue pain receptors.

(Just came back from Truk Lagoon -Saw Pete Mesley and his group there. . .)

 

[bakodiver391]

Hi Kev, Glad to hear you're getting some great diving in. Just finished another great season at Bikini, busier than ever.

 

[Michael Guerrero]

Here's the procedure out of the U.S. Navy Diving Manual version 6:

20‑4.4.2 In-Water Recompression. Recompression in the water should be considered an option of last resort, to be used only when no recompression facility is on site, symptoms are significant and there is no prospect of reaching a recompression facility within a reasonable timeframe (12–24 hours). In an emergency, an uncertified chamber may be used if, in the opinion of a qualified Chamber Supervisor (DSWS Watchstation 305), it is safe to operate. In divers with severe Type II symptoms, or symptoms of arterial gas embolism (e.g., unconsciousness, paralysis, vertigo, respiratory distress (chokes), shock, etc.), the risk of increased harm to the diver from in-water recompression probably outweighs any anticipated benefit. Generally, these individuals should not be recompressed in the water, but should be kept at the surface on 100 percent oxygen, if available, and evacuated to a recompression facility regardless of the delay. The stricken diver should begin breathing 100 percent oxygen immediately (if it is available). Continue breathing oxygen at the surface for 30 minutes before committing to recompress in the water. If symptoms stabilize, improve, or relief on 100 percent oxygen is noted, do not attempt in-water recompression unless symptoms reappear with their original intensity or worsen when oxygen is discontinued. Continue breathing 100 percent oxygen as long as supplies last, up to a maximum time of 12 hours. The patient may be given air breaks as necessary. If surface oxygen proves ineffective after 30 minutes, begin in-water recompression. To avoid hypothermia, it is important to consider water temperature when performing in-water recompression.

20‑4.4.2.2 In-Water Recompression Using Oxygen. If 100 percent oxygen is available to the diver using an oxygen rebreather, an ORCA, or other device, the following in-water recompression procedure should be used instead of Air Treatment Table 1A:

- Put the stricken diver on the UBA and have the diver purge the apparatus at least three times with oxygen.

- Descend to a depth of 30 feet with a standby diver.

- Remain at 30 feet, at rest, for 60 minutes for Type I symptoms and 90 minutes for Type II symptoms. Ascend to 20 feet even if symptoms are still present.

- Decompress to the surface by taking 60-minute stops at 20 feet and 10 feet.

- After surfacing, continue breathing 100 percent oxygen for an additional 3 hours.

- If symptoms persist or recur on the surface, arrange for transport to a recompression facility regardless of the delay.

20‑4.4.2.3 Symptoms After In-Water Recompression. The occurrence of Type II symptoms after in-water recompression is an ominous sign and could progress to severe, debilitating decompression sickness. It should be considered life-threatening. Operational considerations and remoteness of the dive site will dictate the speed with which the diver can be evacuated to a recompression facility.

 

[dschonbrun]

I'm merely parroting what DAN's own Dr. Nick Bird said at "Our World Underwater". You're Bent and You're Where?" was a fantastic presentation. He talked for about 20-30 minutes about IWR and the rare margin where it is a good idea.

It's a rare margin, but the equipment listed is what is called for to attempt IWR. The astronauts of the Apollo 13 mission didn't train to adapt a CO2 scrubber out of duct tape either. However, when you need to save someone from near permanent neurological damage, then you gotta do what you gotta do.

Given your comments, I don't think you understood Nick's presentation. I've studied this topic for a while now and it's fairly misunderstood.

In theory, IWR is just as effective as Chambered recompression from a pure micro-bubble offgassing perspective. However, there is one fundamental difference in practice: In a chamber, the diver/patient can sleep or even be unconscious and still get the benefits. Under water, the diver must be fully alert and able to assist in their own care to get the benefit... and now that he's an active diver, drowning becomes a real possibility.

Given the unpredictability of the Bends, it's rarely a wise move for a recreationally trained diver to go back into the water once decompression sickness symptoms have begun. Best option is to put the diver on oxygen and head to a medical facility above water (on-shore, on-ship).

DS