"Undeserved" DCI

[ellis704]

My husabnd and I dove in Cozumal on March 22, we arrived the day before. We were certified 1 1/2 years ago, and this was dive number 13 (lucky 13!). We had been on the island 24 hours, and did two shallow drift dives that afternoon. The dives were both around 20 meters, 45 minutes in length, SI of 50 minutes, and 3 minute safety stops on both. Nothing stremuous, just easy dives to start our 4 day diving trip. 30 minutes after the dive my husband came down with all the classic symptons of DCI; nausea, vomitting, blurred vision, numbness and tingling in arms and legs. We got a paramedic and they immediately transferred him to the Hyperbaric chamber in town. He was in the chamber within 2 hours of the dive completion. He had 5 chamber treatments, and two oxygen only additional treatments. He was able to fly home a week after the accident, and the only residual effects now is some light tingling in the arms, and some numbness in his calves. Also note that everyone else on the dive, including me, were fine.
My husband is a runner, in good health, slightly elevated blood pressure (is on medication for this) and would like to dive again. We are trying to figure out what may have caused this, this was not a little decompression sickness - he could barely walk after 3 treatments. He was in bad shape. He did work out the morning before the dive - about 1 1/2 hours aerobic, 30 minutes lifting. Could this cause such an extreme case of DCI? Someone thought possbily bad air? Has anyone else heard of this happening?
Any thoughts/suggestions, so that he can consider diving again would be appreciated.

 

[Crush]

Before this degenerates into a war of terminology please consider that the commonly accepted term is unanticipated, not undeserved, DCS. The former draws to mind that dive tables and computers are simply "best guesses" that model the behaviour of most (but not all) humans on most dives.

I heave read on SB that Patent Foramen Ovale can predispose someone to DCS. A link to a PFO page can be found at
http://my.clevelandclinic.org/heart/disorders/congenital/pfo.aspx . I have no expertise in the diagnosis or causes of DCS.

 

[Hawkwood]

You might be better served for an answer if you post in Ask Dr. Decompression. If you would like the post moved, hit the "report" button and ask that a Moderator move it for you.

However, in the meantime check this out from DAN:

Timing of exercise and diving


After accepting the need for regular exercise to maintain or improve physical fitness, the next issue concerns the timing of exercise training and diving. Scheduling outside physical fitness activities can be problematic when someone dives frequently. While part of this is simply a time management problem, there are other considerations. Conducting intense physical exercise too close to diving activity can be problematic for more fundamental reasons.


Bubble formation, while noted earlier as not equivalent to or a guarantee of DCS, can indicate an increased risk for it. Intense physical activity — generally with substantial muscular forces and joint loading, or the application of forces on joints — is believed to transiently increase micronuclei activity, the presumed agent of bubble formation. Intense physical activity too close to diving may therefore be problematic. Physical activity after diving may also stimulate additional bubble formation, possibly through a combination of increased microicronuclei activity and increased joint forces.


Interestingly, some preliminary work has shown that an intense bout of exercise conducted 24 hours prior to diving may reduce bubble presence in humans,3 possibly by inhibiting micronuclei activity. This potentially protective effect was not seen with exercise conducted closer to dive time. While this effect needs to be validated, the preliminary findings may support a simple rule of thumb for scheduling exercise. To reduce the risk, it is a good idea to avoid intense exercise 24 hours before and after diving.


The near-dive window will be best for low-intensity activities. Those who participate in cross-training activities may find it easiest to accommodate this schedule. For those who are more singleminded, diving may fit well into training rest days for those who put the priority on exercise, while training may fit best into diving rest days for those who put the priority on diving. Overall, lower training intensities will likely be more appropriate for the latter group, but accommodations can be reached.

 

[TSandM]

I believe that most of the evidence has not shown a significantly increased risk from PRE-dive exercise, although post-dive exercise is still proscribed. Dr. Deco did some of the research on this, and is a very appropriate person to ask.

With symptoms that severe on profiles that benign, I'd certainly consider a transcranial Doppler to look for shunting. It's a relatively noninvasive test (requires only an IV start) and is reasonably inexpensive.

 

[srhein]

Just curious, what was your average depth? A quick look through the NAUI tables gives me a maximum dive time for the second dive of 11 minutes, using 60 feet as the depth. Were you using computers? If so, did you run a plan for the second dive? Also, if your husband worked out that morning could he have been dehydrated?
Best wishes for his speedy recovery and many future dives.

 

[bleeb]

You might be better served for an answer if you post in Ask Dr. Decompression. If you would like the post moved, hit the "report" button and ask that a Moderator move it for you.

Minor nit: Ask Dr Deco is oriented more towards discussions of the decompression theory (math, models, research, and what not). As Dr Deco says, he's a PhD, not an MD. Medical questions, especially about specific cases, are more appropriate to the Dive Medicine forum, where several experts seem to hang out a lot more regularly.

 

[electrix]

I think it was Capt. Gary of Conch Republic Divers that had a trip to the chamber on the other side of the world after everything seemed to have been done right (diving with Richie Kohler ) and the only reason they came up with he may have been a little dehydrated. I wonder if sometimes people do not drink enough water before diving so that they wont have to pee in their wetsuit. Capt. Gary says to start the day before you go diving and drink plenty of water. It's something to think about.

 

[tc]

If you were using a dive computer it likely will show very different results but in evaluating symptomatic divers we usually refer back to the Navy tables to see what the profile looks like if the dives were square wave.

Dive 1- 20 meters for 40 minutes ends as a Group h.
Surface interval of 50 minutes ends as a group G.
Group G going back to 20 meters has 37 minutes of residual nitrogen time.
NDL at 20 meters is 50 minutes.
Actual dive time 40 minutes + 37 minutes RNT = 77 minutes.

We would not term this an "unexplained" hit. There is a significant amount of exposure here.

Now- that said, your dive were likely multi-level and if using a dive computer the computer would compute the actual depths as the dives progressed producing a very different result. If you did use computers try to get a download of the dives so that your physician (Or a hyperbaric physician if your's does not have the expertise) can review the dives with you and try to determine if there may have been any other contributing factors.

Hope he's feeling better!

 

[boulderjohn]

Just curious, what was your average depth? A quick look through the NAUI tables gives me a maximum dive time for the second dive of 11 minutes, using 60 feet as the depth. Were you using computers? If so, did you run a plan for the second dive? Also, if your husband worked out that morning could he have been dehydrated?
Best wishes for his speedy recovery and many future dives.

Cozumel dives are typically multi-level, so a table that assumes a square profile will not be of much use in this case.

 

[Duke Dive Medicine]

The dive profile and symptom onset are suspicious for a patent foramen ovale (PFO). It would be very reasonable to have him tested. This typically involves either a transthoracic or transesophageal echocardiogram with bubble contrast.