Mild, recurrent DCS - Risk of incurring a more serious DCS hit

[bipolarbear]

Obviously I won't rely on any replies to this thread as medical advice, but I am interested to hear from those with a medical / hyperbaric medicine background as to what they think of my particular situation.

I am a deep / technical / rebreather diver. On four separate occasions over the last three years, I have experienced what I have self-diagnosed to be DCS symptoms. Specifically, shortly after surfacing from certain dives, I have experienced moderate to sever pain in my left shoulder joint, and on one occasion radiating tingling down my left arm with weakness in the grip strength of the left hand. I consider myself a conservative technical diver. I dive a 30/70 gradient factor, try to limit my exertion at depth by using a DPV when available, and I often extend my last stop, particularly on deeper dives, meaning I'm surfacing with a gradient factor closer to 55 or 60.

The four dives I experienced this issue on were:

• a 62 meter open circuit wreck dive for 2 hours, 14 minutes. Minimal exertion. Air was obviously not the appropriate gas but trimix was not available (Truk Lagoon). Gases were air, 50% and 80%. The pain was moderate on this occasion. The pain emerged immediately upon surfacing.
• a 79 meter open circuit dpv open water dive for 1 hour, 24 min. Minimal exertion. Gases were trimix 16/35, trimix 26/23, 50% and 100%. The pain was moderate on this occasion. The pain emerged approximately 15 minutes after surfacing.
• A 45 meter open circuit open water dive for 1 hour, 23 minutes. Moderate exertion swimming into current. Gases were air, 50% and 80%. The pain was moderate to severe on this occasion. This was confusing because this was a very easy dive, with limited deco obligation. The pain emerged immediately after surfacing.
• A 103 meter open circuit wall dive for 1 hour, 48 minutes. There was quite extreme exertion for the first 15 minutes of the dive, swimming into strong current. Gases were trimix 12/675, trimix 20/35, 50% and 80%. This was the first occasion I experienced pain radiating down to my left hand and weakness in my grip strength on that hand. The pain emerged while I was having lunch and a drink, approximately 30 minutes after surfacing. As this was a shore dive with an easy steps entry right next to a dive shop and restaurant, I grabbed a bottle of oxygen and descended to 6 metres. The pain resolved within 5 minutes. I stayed down for 30 minutes in total, and emerged with all issues resolved.

I have been tested for a PFO, which I don't have. I have dislocated my left shoulder quite badly on two occasions, including one occasion where I was hiking in a very remote area and had to 'relocate' the shoulder myself. A subsequent scan showed quite a few bone fragments in that left shoulder.

My (layman's) theory is that there may be scar tissue or other long-term damage in my left shoulder which makes it susceptible to trapping bubbles and causing DCS. One of my rebreather instructors has an identical issue (in the same shoulder, in fact) and while he took a chamber ride on the first occasion it happened, these days he just goes on 02 or if it is bad he does in water recompression.

My question for the experts is if there is any risk that whatever is causing these mild-to-moderate DCS hits could cause something much worse? My main concern is whether a bubble in my shoulder could somehow move around and cause a much more serious spinal bend? I have aspirations to keep diving in the 100-150m range.

In terms of mitigating my risk, I continue to dive conservative gradient factors, and I simply don't do any technical dives that involve any real exertion. I also pay close attention to my temperature on deco. If I'm cold or if I've worked hard on the dive, I extend all of my stops, including my deeper stops. It makes me a pretty irritating dive buddy! I've also moved to closed circuit diving.

I appreciate any insight the community may have. Thank you in advance.

 

[lizardland]

I broke my shoulder on a caving trip years ago and had occasional pain after dives. Hard to say if it is deco related or just cold and physical stress. But when I did get an actual bend that was where symptoms started. Shoulder pain at deco, tingling at the surface. That was after a fairly deep dive (80'ish metres if I remember right), a bit of physical stress (I was fighting an overly floaty scooter on the way up), fatigue and I was also diving the first iteration of VPM which had a reputation for being a bit bendy.

The doc who treated me is a fairly well respected hyperbaric doctor in the UK. He was more of a mind that the previous pain post-dive incidents weren't DCI, it was just an existing injury being aggravated by physical factors. Obviously that's based on the info I was able to give him and not any hard evidence (scans, exams, etc).

Usual caveats with discussing any dive medicine incident, it's an individual event confined to an individual person so I'm not trying to extend my experience to your case.

I also extend my stops. Generally the 6m stop where I hang until I'm bored on as close as I can to a pure oxygen loop. I don't really extend my deep stops, it's more like pauses on the ascent. When I surface I stay on my rebreather on pure O2 for a few minutes afterwards as well. I don't know if it does anything because I've not tested not doing it to see if anything bad happens but equally I've not been bent since so I'll keep doing it. I don't think that experiment would ever pass a peer review

 

[inquis]

I believe I've read similar accounts (perhaps on CCRExplorers?) where an increase in their GFLow was said to be beneficial. I'm certainly not in your shoes, but some of the deco researchers are doing similar depths but no longer at 20/70 or 30/70. Depending on how you're padding the various stops, it might be equivalent to lowering the GFLow, which is opposite of the direction they have moved.

Sorry I can't speak to your question from direct experience, but hopefully the third-person info gives you food for thought.

 

[Duke Dive Medicine]

Obviously I won't rely on any replies to this thread as medical advice, but I am interested to hear from those with a medical / hyperbaric medicine background as to what they think of my particular situation.

I am a deep / technical / rebreather diver. On four separate occasions over the last three years, I have experienced what I have self-diagnosed to be DCS symptoms. Specifically, shortly after surfacing from certain dives, I have experienced moderate to sever pain in my left shoulder joint, and on one occasion radiating tingling down my left arm with weakness in the grip strength of the left hand. I consider myself a conservative technical diver. I dive a 30/70 gradient factor, try to limit my exertion at depth by using a DPV when available, and I often extend my last stop, particularly on deeper dives, meaning I'm surfacing with a gradient factor closer to 55 or 60.

The four dives I experienced this issue on were:

• a 62 meter open circuit wreck dive for 2 hours, 14 minutes. Minimal exertion. Air was obviously not the appropriate gas but trimix was not available (Truk Lagoon). Gases were air, 50% and 80%. The pain was moderate on this occasion. The pain emerged immediately upon surfacing.
• a 79 meter open circuit dpv open water dive for 1 hour, 24 min. Minimal exertion. Gases were trimix 16/35, trimix 26/23, 50% and 100%. The pain was moderate on this occasion. The pain emerged approximately 15 minutes after surfacing.
• A 45 meter open circuit open water dive for 1 hour, 23 minutes. Moderate exertion swimming into current. Gases were air, 50% and 80%. The pain was moderate to severe on this occasion. This was confusing because this was a very easy dive, with limited deco obligation. The pain emerged immediately after surfacing.
• A 103 meter open circuit wall dive for 1 hour, 48 minutes. There was quite extreme exertion for the first 15 minutes of the dive, swimming into strong current. Gases were trimix 12/675, trimix 20/35, 50% and 80%. This was the first occasion I experienced pain radiating down to my left hand and weakness in my grip strength on that hand. The pain emerged while I was having lunch and a drink, approximately 30 minutes after surfacing. As this was a shore dive with an easy steps entry right next to a dive shop and restaurant, I grabbed a bottle of oxygen and descended to 6 metres. The pain resolved within 5 minutes. I stayed down for 30 minutes in total, and emerged with all issues resolved.

I have been tested for a PFO, which I don't have. I have dislocated my left shoulder quite badly on two occasions, including one occasion where I was hiking in a very remote area and had to 'relocate' the shoulder myself. A subsequent scan showed quite a few bone fragments in that left shoulder.

My (layman's) theory is that there may be scar tissue or other long-term damage in my left shoulder which makes it susceptible to trapping bubbles and causing DCS. One of my rebreather instructors has an identical issue (in the same shoulder, in fact) and while he took a chamber ride on the first occasion it happened, these days he just goes on 02 or if it is bad he does in water recompression.

My question for the experts is if there is any risk that whatever is causing these mild-to-moderate DCS hits could cause something much worse? My main concern is whether a bubble in my shoulder could somehow move around and cause a much more serious spinal bend? I have aspirations to keep diving in the 100-150m range.

In terms of mitigating my risk, I continue to dive conservative gradient factors, and I simply don't do any technical dives that involve any real exertion. I also pay close attention to my temperature on deco. If I'm cold or if I've worked hard on the dive, I extend all of my stops, including my deeper stops. It makes me a pretty irritating dive buddy! I've also moved to closed circuit diving.

I appreciate any insight the community may have. Thank you in advance.

A bubble in your shoulder joint won't translocate to someplace where it could cause worse symptoms, but if you're having repeated incidents of DCS in the same joint you're at risk for aseptic osteonecrosis.

Best regards,
DDM

 

[Germie]

I dive sometimes with a diver who had re-occurent lymphatic dcs in his shoulders. Most times on the same site. It is getting thick, not very painful, just a strange feeling.
He is also doing technical dives and we figured out how we can avoid this.

He is diving on 40/70 or 50/70, so let's say not doing the deepstops. The 40 or 50 is for most dives we do not important as it is not deeper than 74m and most times no open water, but caves. Then on the 6m stop he uses 80-100% oxygen, even if the dive was quite shallow and you can do it with just a 50%. On CCR, pumping up to 1.6 PO2 from around 10m. Then from 6m to surface with 1m/minute, or if there are waves, stay for 5-6 minutes as shallow as possible, so around 3m most times.

Then, hold the loop or oxygen reg in your mouth till you can get get in the boat, or walk with the loop in your mouth to the car.

The surface interval for the next dive is very important for this person, as the dcs occured every time after the second dive of the day. So we wait now for 3 hours or more till we do a second dive. If that is not possible, we stick with only 1.

So maybe you can figure out if it happens after a second dive too, and how long the surface interval was. Also take that extra 5-6 minutes after finishing deco to reach the surface. And if you do shallower dives within NDL, do a 12-9-6m 1 minute stop extra and then the normal safetystop at 5 or 3m.

 

[Dominik_E]

I would guess if that is indeed DCS (very hard to really tell, as you are also saying), it may be an indication that you are pushing the boundaries of what your body will tolerate. So while those very same bubbles that cause the hurt will go nowhere critical, a future dive may still be by accident "beyond the edge" where more severe symptoms may be involved. If it was me, I would potentially do longer deco, and/or keep breathing O2 for some interval at surface.

 

[grantmac]

Seems to me staying on the loop a while at the surface would be very cheap insurance.