Undeserved hit

[DivingDoc]

While we are on the subject of diving accidents, we just took my whole family -- my husband, 24 yr old daughter, son-in-law, and 20 year old son on a week of diving in Cozumel. My son-in-law had completed his open water cert in preparation for the week's vacation.

The first day of real diving went fine (2 check dives on first afternoon and next morning) -- a 50 foot max depth dive followed by a 1 hr survace interval followed by a 40 foot or so depth dive. The second day, we did an 80 foot max. multilevel dive followed by a 50-60 foot max multilevel dive, separated by a 1hr and 15 minute surface interval. (These depths and times are not exact -- I'm going to have to download their profiles from their dive computers.) After a 6 hr surface interval, we did a night dive in 50 or so feet. My daughter, Petra, and SIL came up relatively soon, since there were enormous clouds of plankton and they found it quite disorienting. On the ascent, they temporarily ascended too fast to 6 feet, but were quickly pulled down by the divemaster. During the ascent, my daughter felt that she had gotten some plankton in her ear, and tried to pluck them out. She felt immediate pain and later was found to have perforated her ear drum. She also had vertigo for a week.

At 4AM, John, my SIL, developed nausea and vomiting, followed by diarrhea. At 9:15 or so, he came over to our room complaining of tingling in his left forearm. By 9:30, he was complaining of tingling in his left arm and left leg. I tested his strength and it was symmetrical. But within 20 more minutes, he complained of SOB. We got him back over to the Dive House via wheel chair by 10 AM, where a diving physician examined him, and felt that he had DCS. He required two 5 hr treatments in the recompression chamber, which was 15 minutes away by taxi. He had nausea and vomiting the whole time he was in the chamber and afterwards developed a shaking chill followed by a fever to 101.5 F. Six days later he still has loose stools, despite Cipro. The DCS symptoms were all cleared up with 2 5-Hr recompression treatments. The doctor at the Hyperbaric center felt that it was the dehydration brought about by the gastroenteritis which precipitated the DCS.

All the dives were within NDL's. We really weren't sure why he developed DCS. Ten other divers did the same dives that day and the day before, although, of course, each diver's profile is a little bit different, even though they are on the same dive. The only thing that the people in the Hyperbaric center could figure was that the gastroenteritis had dehydrated him and precipitated the bubble formation.

There were about 5 other divers who were under going treatments during the 2 days that John was having his treatments. That leaves me to believe that DCS is more common than advertised. There are about 80,000 dives per year in Cozumel.

Any thoughts?

 

[Dr Deco]

Dear Diving Doc:

Unilateral Tingling

I am suspicious of DCS appearing with such a time delay as described. I am further suspicious of dehydration precipitating this later. Dehydration is usually described as a causative factor in reducing plasma volume and thus tissue perfusion. Before this occurred, however, the dissolve nitrogen would have been eliminated from the tissues. It possible that volume loss could concentrate surfactants and it would thus lead to bubble growth, but I would be suspicious of this as a mechanism in this case.

I would guess that one is looking at a toxic reaction to something in the water – even if the tingling was unilateral (and without a decrease in motor function).

DCS

The truth is that many things are cleared by high partial pressures of oxygen. This toxic reaction could well be one of them.

I would be surprised that there would be five DCS cases during the coupe of days. We may be looking at a very liberal and creative diagnosis on the part of the chamber staff.

Dr Deco :doctor:

Please note the next class in Decompression Physiology :grad:
http://wrigley.usc.edu/hyperbaric/advdeco.htm

 

[DivingDoc]

Dr Deco once bubbled...
Dear Diving Doc:

Unilateral Tingling

I am suspicious of DCS appearing with such a time delay as described. I am further suspicious of dehydration precipitating this later. Dehydration is usually described as a causative factor in reducing plasma volume and thus tissue perfusion. Before this occurred, however, the dissolve nitrogen would have been eliminated from the tissues. It possible that volume loss could concentrate surfactants and it would thus lead to bubble growth, but I would be suspicious of this as a mechanism in this case.

I would guess that one is looking at a toxic reaction to something in the water – even if the tingling was unilateral (and without a decrease in motor function).

DCS

The truth is that many things are cleared by high partial pressures of oxygen. This toxic reaction could well be one of them.

I would be surprised that there would be five DCS cases during the coupe of days. We may be looking at a very liberal and creative diagnosis on the part of the chamber staff.

Dr Deco :doctor:

Please note the next class in Decompression Physiology :grad:
http://wrigley.usc.edu/hyperbaric/advdeco.htm

Well -- I don't know. By the time John got to the chamber, he definitely couldn't walk. He had to be carried in. The chamber is DAN affiliated, the medical staff is DAN trained and are in constant communication with DAN. John did make a dramatic improvement over two days of recompression treatnments, though 5 days later, he still has significant diarrhea, though it seemed to initially respond to Cipro.

I don't know all the details of the other cases. One woman came up to the boat and was suddenly paralysed from the waist down. She recovered, and was stupid enough to carry her gear back to the hotel, after which the paralysis recurred. She required a week of treatments. She was also diving within DNL's.

The staff at the Hyperbaric Chamber tell us that in busy season (e.g. spring break), they will see 25 cases in a month. Again, this seems high for a place that has 80,000 dives per year. This comes out to an average of 6666 dives per month. Even if the number of dives during the busy seasons were double -- around 130000, 25 cases in the month would give you an incidence of around 1 in every 533 dives, which is much higher than the 1 in every 250,000 dives that I have heard before.

 

[Dr Deco]

Dear ET:

The inability to walk would indeed make a difference. Now that sound likes neurological DCS - particulary if recompression improved it.

Mike Powell :doctor:

 

[Charlie99]

DivingDoc once bubbled...
The staff at the Hyperbaric Chamber tell us that in busy season (e.g. spring break), they will see 25 cases in a month. Again, this seems high for a place that has 80,000 dives per year. This comes out to an average of 6666 dives per month. Even if the number of dives during the busy seasons were double -- around 130000, 25 cases in the month would give you an incidence of around 1 in every 533 dives, which is much higher than the 1 in every 250,000 dives that I have heard before.

First of all, the rates I've seen repeatedly quoted are around 1 per 10,000 to 1 per 45,000 dives.

I believe, although without direct personal knowledge, that all of the chambers in Cozumel file incident reports with DAN.

The 80,000 dives per year number that you quote is difficult to believe. 80,000/365 days per year means an average of 220 dives per day. Assuming 2 tank boat trips, that means only 110 divers on the island on average. Way too low. Probably by a factor of 10 or more.

Charlie

 

[DivingDoc]

Charlie99 once bubbled...
First of all, the rates I've seen repeatedly quoted are around 1 per 10,000 to 1 per 45,000 dives.

I believe, although without direct personal knowledge, that all of the chambers in Cozumel file incident reports with DAN.

The 80,000 dives per year number that you quote is difficult to believe. 80,000/365 days per year means an average of 220 dives per day. Assuming 2 tank boat trips, that means only 110 divers on the island on average. Way too low. Probably by a factor of 10 or more.

Charlie

So you think that the 80,000 number is low? I suppose our group of 26 people alone did a minimum of 2 dives per day plus one night dive -- 11 dives per person for the week (one day off in the middle for safety), with some divers doing up to 4 per day. That would be around 300 dives for the week just with our group alone. Hmmm -- 80,000 dives per year is the figure quoted by the chamber staff.

 

[The Iceni]

If this was indeed DCI, and it appears to have been neurological, could this be yet another example of DCI preciptated by a patent foramen ovale?

For obvious reasons I tend to think this is a more common cause of unexpected DCI than hitherto recorded. Certainly in my own case it will not figure anywhere in the statistics because the (self) diagnosis was retrospective. (DCI was not even considered in the differential diagnoses)

 

[DivingDoc]

Dr Deco once bubbled...
Dear ET:

The inability to walk would indeed make a difference. Now that sound likes neurological DCS - particulary if recompression improved it.

Mike Powell :doctor:

Yes, although when I tested his strength initially it was symmetrical, he subsequently became SOB, and then unsteady on his feet. By the time he reached the Hyperbaric Center -- 30 minutes later-- he was unable to walk on his own. They had to hold him up for the Chest Xray and carry him into the chamber. After 5 hrs of recompression treatment, he was able to walk out on his own steam, although he continued to have vomiting and diarrhea and later that evening spiked a temp to 101.5 F.

 

[Saturation]

DivingDoc once bubbled...
Petra, and SIL came up relatively soon temporarily ascended too fast to 6 feet, my daughter felt that she had gotten some plankton in her ear, and tried to pluck them out. She felt immediate pain and later was found to have perforated her ear drum. She also had vertigo for a week.

At 4AM, John, my SIL, developed nausea and vomiting, followed by diarrhea. At 9:15 or so, he came over to our room complaining of tingling in his left forearm. By 9:30, he was complaining of tingling in his left arm and left leg. I tested his strength and it was symmetrical. But within 20 more minutes, he complained of SOB. ...He required two 5 hr treatments in the recompression chamber, which was 15 minutes away by taxi. He had nausea and vomiting the whole time he was in the chamber and afterwards developed a shaking chill followed by a fever to 101.5 F. Six days later he still has loose stools, despite Cipro. The DCS symptoms were all cleared up with 2 5-Hr recompression treatments. The doctor at the Hyperbaric center felt that it was the dehydration brought about by the gastroenteritis which precipitated the DCS.

There were about 5 other divers who were under going treatments during the 2 days that John was having his treatments. That leaves me to believe that DCS is more common than advertised. There are about 80,000 dives per year in Cozumel.

Any thoughts?

Hi Dd:

That DCI symptoms disappeared while the flu-like syndrome persisted after, presumably, 2 Treatment Table 6s suggest SIL did have mild DCI, but that they manifested as hemiparesthesias or later mono/hemiplegia and some dyspnea is a tad concerning.

Assuming these are all organic and not psychological reactions to acute illness, the accident reads like SIL and Petra were buddied on the dive were a rapid ascent was enough to rupture Petra's ED. Assuming Petra was not ill and has normal ED, such an ascent at worse could provide enough bubbles to arterialize in the presence of a PFO or even form autochthonous CNS bubbles [de novo bubbles], both would manifest as CNS symptoms either in the brain or spinal cord. That they were treated early likely had a role in the complete resolution of DCI symptoms. However, as autochthonous bubbles are less common, there is some elective consideration for SIL to check for a PFO, as this is common occurrence. Advances in PFO therapy offer less risky solutions to closure.

DCI risk has not been well documented in relation to altered physiologic, thus risk, patterns with concurrent acute illness. However, risk of DCI is known to increase _or_ decrease with types of drugs or hormones. Since altered perfusion patterns and release of various metabolites, acute phase reactants, hormones, etc., occur during illness, its very likely that beyond dehydration, the viral syndrome too provided impetus to accelerate DCI.

A PFO eval is a strong consideration if symptomatic, and while SIL's precipitating conditions are unusual, i.e., the viral syndrome may play a bigger role, stress related DCI are often joint bends.

I don't know the incidence of bends across different chamber areas but my view of the numbers you present suggests that Cozumel diving is more rigorous than the skill level of its participants or that Cozumel is much busier than Caymans for diving [~ 12/mo]. In discussions in Caymans ER staff, they treat about 1/3 of DCI cases sent to them for evaluation. Diving in currents is best for divers with some experience. I do know that qualitatively, the bends rate in the continental US is substantially lower ... but quality control and supervision in popular areas [ Fl and CA] is more rigorous.

I'm gearing up to leave on a diving safari so I may not reply. Glad it all worked out.

 

[Dr Deco]

Dear Doctors: :doctor:

PFO

I am also suspicious that this is more common than expected. There are a considerable number of cases of neurological DCI reported by recreational divers. The data indicates that it is equal to incidence of pain-only DCS in recreational scuba. I suspect that there are a large number of missed cases of “bends” and self-resolution will take care of more. Many divers are of the opinion that they will be writhing in pain with “the bends” and this is simply not so. Thus, in a laboratory setting, a test of pressure might be needed to clinch the diagnosis. In the field, the diver would probably simply dismiss this as an ache or sprain.

We virtually never see neurological DCI in the laboratory where recreational diving is tested. We do not ever perform Valsalva-like maneuvers in the lab (e.g., lifting, straining, climbing, etc). To do this would probably lead to serious DCS and such a test most likely would not be allowed by an Institutional Review Board.

SOB

I wonder if the son in law had a case of “the chokes” as indicated by the shortness of breath. Breathing difficulties are not common in DCS and, when they are, indicate a pulmonary involvement. This malady is thought to be associated with numerous gas bubbles in the pulmonary circulation. Whether there is a problem with gas exchange because of embolism or whether the cause is irritation by bubbles and vasoconstriction is not known. Numerous bubbles in the pulmonary circulation could well be associated with arterialization.

Dr Deco :doctor:

Scuba Board readers please note the next class in Decompression Physiology :grad:
http://wrigley.usc.edu/hyperbaric/advdeco.htm