DCS treatment

[h20_kat]

I've had a hit of DCS while on holiday in Fiji. Symptoms developed slowly so it took a couple days before I realised there was something wrong. Then it was a further day and a half before I was able to get into the chamber for treatment. I had limited oxygen during this time. I had a US Navy table 6 treatment yesterday (4 hrs 45 mins) which improved my fatigue a lot and my thinking/talking ability a fair bit. The tingling in my right foot got better but the right arm/hand which seemed better initially was numb/tingling again a few hours after treatment. I had a second treatment today - called an 18/60/30 (roughly 2 hours). Now I have some pain in my back, an area which didn't bother me before. Additionally I now have an itchy skin rash on my collarbone/neck which I didn't have previously.

Unfortunately there is no hyperbaric doctor in Fiji right now so I am not that confident in my treatment. The chamber treatments are being managed by an anesthesiologist. I have had some limited discussion with DAN but not spoken with a dive doctor since the new symptoms have appeared. It was agreed to talk tomorrow morning when I return to the chamber for reassessment.

I am rather worried as I have new symptoms after treatment. Is this normal? Should I be worried? Could they be doing something wrong with the treatment?

 

[Dr Deco]

Hello h20 kat:

The time course for this does not sound like DCS - a very late appearance if I read this correctly. It sounds like envenomation from some sea creature.

Let us see what the other medical doctors think about this.

 

[h20_kat]

It started with tiredness and a headache. I passed this off as something else. I did a couple more days of diving which I think made symptoms worse and other symptoms appeared. My thinking and memory started to be affected and I started to get numbness/tingling in my right arm and right foot. So I don't think it was late onset just slow recognition of the symptoms.

---------- Post added October 12th, 2013 at 08:02 PM ----------

Both DAN doctor and my treating doctor here in Fiji think the rash is unrelated, possibly an allergic reaction of some sort. I am trying hydro-cortisone cream to see if that helps.

My third treatment today has left me feeling quite a bit better. Looks like I will have at least a couple more at a shallower depth. Thanks for your input Dr Deco.

 

[Red Sea Shadow]

Would you please tell us more about the dives, particularly the one or two just before the symptoms start to manifest themselves?

 

[h20_kat]

Here are the series of dives. All multi-level dives on air with 3-5 minute safety stops. No ascent rate or NDL violations on Suunto Vyper 2.

Day 1
dive 1 - max 21.4 m for 56 min. SI 1:08
dive 2 - max 18.8 m for 60 min

Day 2
dive 1 - max 23.7 m for 54 min. SI 1 hour
dive 2 - max 21.2 m for 55 min

Day 3
dive 1 - max 20.6 m for 55 min. SI 54 minutes.
dive 2 - max 20.2 m for 60 min

Day 4
dive 1 - max 21.6 m for 57 min. SI 56 min
dive 2 - max 22.4 m for 64 min

The tiredness/headache was after the second day of diving. Other symptoms did not appear until after the 4th day. e.g. dizziness, tingling/numbness, difficulty with thinking/talking and memory

I am guessing the contributing factors are: short surface intervals, tiredness due to travel, perhaps being cold. The water temp was 25 degrees and I was in a wetsuit and a sharkskin. I am usually diving in 29-30 degrees in a wetsuit or else cold water in a drysuit. That being said, others were diving in shorties! But I tend to really feel the cold.

 

[h20_kat]

I just thought I would follow up with what has happened since. I ended up having 5 treatments in the chamber in Fiji. The doctor there wanted to do a couple additional treatments but DAN felt I had had enough. I wasn't sure who was right - a doctor who was not a diving expert and didn't seem to do much to assess my condition/improvement or a dive doctor assessing me over the phone with limited information. This part was really frustrating and scary as I really don't know whether I had adequate treatment. I then had 3 days rest before getting on a flight back to Auckland. A few days later I saw a dive doctor at the nearest hyperbaric chamber which was arranged through DAN. I still have tingling arms/hands, my concentration/memory isn't yet back to full ability and I have been sleeping more than usual. All of these symptoms have been gradually improving in the week I have been back. However, my right leg tingling which seemed to be gone after treatment has returned. The dive doctor here has said I will recover in time, but it could be weeks or months.

 

[DocVikingo]

I wasn't sure who was right - a doctor who was not a diving expert and didn't seem to do much to assess my condition/improvement or a dive doctor assessing me over the phone with limited information...my right leg tingling which seemed to be gone after treatment has returned. The dive doctor here has said I will recover in time, but it could be weeks or months.

Hi h20_kat,

While the reported profiles & onsets may be a bit atypical, and a few of the complaints may not be due to scuba-related gas phase issues (e.g., recent back pain, skin rash (provided it isn't cutaneous DCI)), the overall picture appears consistent with neurological DCI.

Anxiety over which of the docs involved to listen to certainly is understandable. However, the DAN doc most probably was able to obtain sufficient information from speaking with you & with the treating anesthesiologist in order to make a reasoned decision regarding discontinuance of chamber sessions. While such decisions are made on a case by case basis, in most instances of mild to moderate neurological DCI five treatments are adequate. And apparently the diving medicine expert consulted upon return to Auckland concurred as no additional treatment for DCI has been prescribed.

As for the remaining tingling in the R-leg, it is not uncommon for such paresthesias to remit under recompression only to return shortly after release from the chamber. However, while there are no guarantees, the typical course of residual post-recompression paresthesias suggests that this eventually will resolve.

Regards,

DocVikingo

This is educational only and does not constitute or imply a doctor-patient relationship. It is not medical advice to you or any other individual and should not be construed as such.

 

[Akimbo]

I concur. Five Table 5 treatments over so many days since the onset of symptoms almost certainly would yield miniscule returns, if any. Any residual Nitrogen would have dissipated days before your last treatment, and probably before your first. Positive effects of super-oxygenation from more chamber rides are also questionable at this point.

The efficacy of hyperbaric treatments for DCS diminishes rapidly as time passes since your last dive. It is critical to perform hyperbaric treatment as soon after surfacing from your last dive as possible to prevent damage, as opposed to trying to repair it. Trusting DAN is the right thing at this late date.

I was the inside-tender on a treatment in the 1970s on a competitor's saturation diver found unconscious on the street in Stavanger Norway. Once alcohol was ruled out we started a table 5, which quickly slide into a 5a. Fortunately we were in a multi-chamber sat system. He regained consciousness at about 150'. He repeatedly lost consciousness on ascent so we slide into a saturation decompression table with high O2 treatments on BIBS (Built-In Breathing System) for him. We learned during decompression that he had not been under pressure for weeks before the event but we couldn't just let him pass out again since the treatment was working. Besides, all three of us were also committed to a sat decompression schedule by then anyway.

He left the chamber symptom free after several days of "treatment". I heard from the attending doc about a month later that he passed out again in Scotland. He had not been under pressure since we treated him and was diagnosed with some weird form (my words) of spinal meningitis. This is a case where he responded to treatment but had nothing to do with DCS.

The point is not to suggest you have some bizarre disease, but that super-oxygenation experienced during DCS treatment can sometimes make unrelated symptoms subside or disappear. Please let us know if how your recovery progresses.

 

[DocVikingo]

...super-oxygenation experienced during DCS treatment can sometimes make unrelated symptoms subside or disappear.

Indeed it can. This is an excellent point to keep in mind when assessing patterns in chamber treated signs & symptoms.

Cheers,

DocV

---------- Post added October 25th, 2013 at 10:17 AM ----------

The efficacy of hyperbaric treatments for DCS diminishes rapidly as time passes since your last dive. It is critical to perform hyperbaric treatment as soon after surfacing from your last dive as possible to prevent damage, as opposed to trying to repair it.

Current thinking on the efficacy and speed of commencing hyperbaric treatment seems to be along the lines of the findings of the below study:

"Diving Hyperb Med. 2011 Sep;41(3):129-34.

Risk factors and clinical outcome in military divers with neurological decompression sickness: influence of time to recompression.

Blatteau JE, Gempp E, Constantin P, Louge P.

Source

Chef de l'Equipe Residante de Recherche Subaquatique Operationnelle (ERRSO), Institut de Recherche Biomedicale des Armees (IRBA), Toulon, France.

Abstract

BACKGROUND:

This study was designed to examine the influence of short delay to recompression and other risk factors associated with the development of severe neurological decompression sickness (DCS) in military divers.

METHODS:

Fifty-nine divers with DCS treated in less than 6 hours from onset of symptoms to hyperbaric recompression were included retrospectively. Diving parameters, symptom latency and recompression delay were analysed. Clinical symptoms were evaluated for both the acute event and one month later.

RESULTS:

Median delay to hyperbaric treatment was 35 min (2-350 min). Resolution was incomplete after one month in 25.4 % of divers with DCS. Multivariate analysis demonstrated that severe symptoms, classified as sensory and motor deficits or the presence of bladder dysfunction, were predictors of poor recovery with adjusted odds ratios (OR) of 4.1 (1.12 to 14.92) and 9.99 (1.5 to 66.34) respectively. There was a relationship between a longer delay to treatment and incomplete recovery, but the increased risk appeared negligible with an adjusted OR of 1.01 (1-1.02).

CONCLUSION:

Our results suggest that neurological severity upon occurrence is the main independent risk factor associated with a poor outcome in military divers with DCS. Clinical recovery was not dramatically improved in this series when recompression treatment was performed promptly.”


While I do not interpret these findings as suggesting that speed in starting hyperbaric tx is not important, but rather that within reason it may not be critical, and especially not critical enough to engage in risky haste in seeking recompression, be that risky transport methods or risky treatment approaches (e.g., in water recompression (IWR)). I think the important take-away from the research to date is that supervising dive professionals and medical personnel should weigh the risks and benefits of various evacuation and treatment methods when determining how an injured diver will be transported and medically handled.

Cheers,

DocV

 

[Akimbo]

…This study was designed to examine the influence of short delay to recompression and other risk factors associated with the development of severe neurological decompression sickness (DCS) in military divers…

Interesting, but outside the scope of my comments. I was referring to the more common joint pain symptoms that represent the vast majority of DCS treatments I have been involved in. [edit]: I should have been more clear.

No doubt we over treated a lot of symptoms. We would slam a diver in the barrel at the least hint of a symptom. Neurological symptoms were extremely rare, though they may well have developed in a few cases had the diver not been recompressed quickly. I would estimate the typical time to shut the hatch for recompression would be well under 10 minutes after reporting symptoms/suspicions to the dive supervisor.

The motivation for this aggressive treatment approach was both humanitarian and commercial. Most operations could run a treatment and continue diving ops for a short time but when the treatment ran more than about 3 hours (one table 5) diving operations had to stop (as in going off-contract). Projects like this usually had two double-lock chambers onboard.

Superficially and not having read the study, I am not surprised that the French Navy would have enough DCS cases with severe neurological symptoms to be statistically significant. Unless things have changed, the French Navy and commercial diving companies were much more aggressive in their tables than in the US and UK, especially for mixed gas.

…
CONCLUSION:

Our results suggest that neurological severity upon occurrence is the main independent risk factor associated with a poor outcome in military divers with DCS. Clinical recovery was not dramatically improved in this series when recompression treatment was performed promptly.”…

That is entirely consistent with my limited experience and training. Severe neurological symptoms were “considered” by most supervisors to be cases where the “damage has already been done” where milder symptoms treated in a timely manner “probably” would prevent long term damage.