Bad Luck

[The Iceni]

Originally posted by zelevin
So - let me see - is sneezing when getting out of water potentially dangerous as well for people with PFO? Ouch.

- Vladimir

Dr Vikingo is quite right to add the risks of a joint DCI to this discussion and it was remiss of me to leave it out.

Vladimir, You described a type II DCI, where you had quite alarming symtoms related to your central nervous system and to my mind this can only, commonly, occur in two situations.

1) A rapid ascent ( or an ascent with missed stops) which leads to the formation of bubble seeds in soft tissues themselves, or

2) Bubble nuclei from the venous circulation finding their way into the arterial circulation embolising to vital organs in which they lodge, then growing as they take on more gas at the surface. This can only occur when a right to left shunt exists .

Variations on the Valsalva manouevre performed by divers include forcefully clearing your ears, straining to carry heavy equipment ("grunting"), coughing and yes sneezing. I cannot imagine anything a human being could do that could cause a more explosive change to the intrathoracic pressure than to sneeze! A sneeze is produced by a rapid reflex contraction of the diaphragm and the muscles of the chest wall in order to to expel the contents of the nasal airways, followed by an immediate return to normal. So if anything could cause a bolus of blood to pass through any shunt a sneeze is first on my list.

By the way, A PFO is certainly not the only cause of type II DCI. I was recently contacted by a very experienced diver who had suffered a neurological DCI following a very leasurely dive to 20 metres (66 feet) for 18 minutes with a five miute safety stop at 6 metres. Personally I doubt this DCI was due to a shunt because, if he had a significant PFO I would have expected him to have suffered a DCI much earlier in his 16 year diving career and he had done nothing to precipitate such a DCI.

It transpired that he had suffered a prolapsed intervertebral disc some twenty years ago, which had caused spinal nerve compression at the time. He had to stay off work until he was cured by means of a spinal operation, a laminectomy.

I feel this may have been the culprit in his case, particularly as the distribution of the neurological deficite from the DCI mirrored exactly the side and the level of the damage from his original PID.
All operations produce potential spaces and the blood supply to scar tissue is very poor. We may never know the real culprit but if he is wise, I suspect this chap's diving career is over.

I wonder what Dr Vikingo or the other regulators make of this incident.

 

[Dr Deco]

Dear Readers:

Sneezing

From the question on “Sneezing,” individuals might leave with the impression that what they might have thought was trivial might actually not be so trivial after all. As a matter of fact, depending on when this occurred in the surface interval. It could be a factor in DCS risk.

Let us examine two scenarios. In the first, Diver A surfaces and is helped aboard the boat by the dive crew. He sits down on the boat and rests during the surface interval.

Diver B surfaces but climbs onto the boat will all of his gear. A couple of minutes latter, he sneezes three times. Very shortly thereafter, he has an episode of neurological DCS. Both divers might show that they were “within the tables,” but one got a hit and not the other. Both will say that they were within the tables and diving conservatively. Diver B was not conservative within the definition of two-phase gas mechanics. The class on decompression physiology that I teach has the description that “it is taught from the perspective of the free gas phase and not from the aspect of tissue gas saturations.” That means I do not care as much about the gas loads as I do with what you did with them. This is lumped together as the Synoptic Model of decompression.

Sneezing after exertion

We can see in the attachment that the test subject has pulled himself with his arms and a large number of Doppler-detectable gas bubbles have arisen in that arm. (This is an actual experiment, but without the actual sneezing at this time. The subjects have since been told not to pull with the arms or legs.) If Diver B had also sneezed, it could well have lead to arterialization through a PFO.

Sometimes little things make a big difference.:boom:

Dr Deco :doctor:

 

[rcohn]

Dr Deco,

Am I reading the graph correctly? It seems to show that while the test subject had an early spike in bubble volume, the bubbles dissipated relatively quickly and he had a lower overall bubble volume than the average of the test group. Am I missing something?

Ralph

 

[Dr Deco]

Dear Ralph:

This subject was apparently of the “resistant” type with respect to bubble formation (under these conditions) except for the fact that he pulled with his arms to move himself during the hypobaric condition. I have included him as well as the averages for the group to indicate that normally gas bubble formation would not have been expected so early in the trial. He strained his muscles, produced gas bubbles, and these persisted for about one hour.

Since he was asked to not strain again (other than the prescribed, lighter, series of exercises), he did not produce any more bubbles. He was “below average” as far as bubble production was concerned for the remainder of the test. The point is, however, because of this straining maneuver, he caused (what was for him) a very big generation of decompression gas bubbles.

Dr Deco :doctor:

 

[DocVikingo]

Hi Dr. Thomas,

In the chap you reference, it would be important to know such things as how aggressive his diving had been in the hours & days prior to the event, state of general health, level of hydration & other factors known or suspected to be involved in precipitating DCS.

There are of course no guarantees with DCS. However, if it occurred against a background of good fitness to dive and within the context of an otherwise uneventful single dive to 66' for 18" with a 5" safety stop at 20', then it does make one wonder.

How confident was the diagnosis of Type II DCS? Any chance that he retraumatized the area of spine involved initially (tanks & weight belts can be hard on the vertebral column), irritated adhesions or the like? While I've always found "the blood supply to scar tissue is very poor" hypothesis in DCS intuitively compelling, based on my admittedly limited knowledge the research data in support this is rather weak.

Best regards.

DocVikingo

 

[The Iceni]

Thank you for your input Dr Vikingo,

The reference diver send me copies of his medical history, dive profile and diving history.

He is an otherwise fit 55-year-old with hundreds of dives on his slate, many one might call "technical" and he is currently the training officer of his club.

On the day in question it was the first dive on the Saturday following a week of normal work. He was a passenger in the car - an hour's journey - and he took his single trainee buddy on his first open water dive in flooded quarry which is very popular for training, being at three levels; 7 metres, 19-21 metres and 32 metres in which there can be found many sites of interest on the bottom, such as a helicopter, a midget submarine and even a small trawler.

On the telephone I closely questioned him about predisposing factors such as dehydration, stress, forcibly clearing his ears, sneezing and carrying heavy kit at the end of the dive. He sounded genuine and admitted to none of these, which is why he was so aggrieved and puzzled to have DCI develop on what appeared to be a very, very conservative dive indeed and DAN could not help. In fact the period at the 6 metre "stop" was not compulsory. It was to allow his trainee to practice keeping station at that depth and after the dive his kit had been left on the shore line.

I also wondered whether, with a history of the severe PID he described, whether this was not DCI, but in fact a simple recurrence of this, but he had not carried his kit or weight belt to the car and he developed his symptoms relatively slowly within five minutes of surfacing and they improved with 100% oxygen only to return later in the ambulance. He was airlifted to the nearest recompression facility, was diagnosed as having DCI and treated with US navy treatment table 6 which was almost completely curative. His only remaining symptom being a small area of numbness over his left foot in the dermatome of L5. (His PID was at L4/5).

His reason for contacting me was his frustration at having to wait over three months for an echo ( at considerable cost), to exclude a PFO, when he was convinced that he was very unlikely to have one because of his previous event-free diving history.

He had done his research!

Should he pay for such a test when if it was positive he could not afford the necessary private treatment (It is not available of our NHS and he is not insured) and if it proved negative he would be back where he started but nearly $1,000 poorer?

I could not answer his obvious question "If I do not have a PFO am I more likely to have another, similar, DCI?"

Of course, I could not reassure him and advised caution.

So, a very puzzled and unhappy man indeed.

Any more ideas?

Kind regards,

 

[DocVikingo]

Hi Dr. Thomas,

Given that background, seems very likely it was Type II DCS.

Thanks,

DocVikingo

 

[Dr Deco]

Dear Readers:

Neurological DCS

The response to the question on “Coughing” is apropos to this thread. Please check out the section on “How to get DCS.”

Dr Deco :doctor:

 

[deepsix]

I thank all that have replied to my posting. I'm sorry that I did not get back sooner, I have been away. I now have an appointment for a cat scan perphaps that will tell how bad things are. The next morning after the dive, it was both of my legs and feet along with my right hand and fore arm to my elbow and lower right back that were numb again. However now my right arm and hand are back to normal. It was never as bad as my legs. So I hope with time the rest will return to normal.

Oh boy here we go, This is for you mtdivegirl. I did not want to dwell on the past because one I did not have the time then, and two I'm a sloooow typer and this is a long story. However if letting every one know about all the dumb mistakes that I made, (another reason why I did not want to dwell on the past.) will help keep some one else from getting bent, then I guess it is worth it. As they say learn from others mistakes. Bare with me, my spelling is not that great so there is bound to be alot of errors along the way.

Before I start I would like to say that I don't blame any one but myself. I am responsable for my own actions. However as I said before I found out alot of my information after I got bent. Like no hot showers after diving. I have talked with a friend that took a dive corse from a different organization other than the one I did.
By the sounds of things he learnt alot more than I did. His course was 6 weeks mine was 2 weekends. BIG differents.

Ok, here we go it was Tuesday June 18 after super. Three of us went out on a boat to go scallop diving. Dive 1 myself and one other went into the water. 64 feet 20 mins very few scallops found. So we went deeper. Yes I know, deep dives frist then shallow. Both other divers have alot more experience than I, so I thought nothing of it. 92 feet the third diver goes by himself. A few more scallops now. Time on the surface about an hour and a half. The other diver and myself are going again. Still 92 feet. By this time it is still light out however the sun is going down fast. The other diver is in the water frist, he is told to wait for me dew to my lack of experience. Plus this was going to be my deepest dive to date.

I'm sorry about this but I have to go. I still have tomorrow before I leave again so I will try to finish my story then. Other wise it will be another couple of weeks.

 

[deepsix]

Ok I'm back as I said sorry for the cut off yesterday.
I finally get into the water and we start to descend. The other diver always goes down alot faster than I. I have trouble clearing my right ear at times. I get down about ten feet when I realize that my snorkel is caught up under my regulator hoses. This was putting pressure against my mask so I had to surface. By this time the other diver was long gone out of my sight. I fixed the snorkel problem, then waited on the surface to see if the other diver was going to come back up. He never did, so I went down on my own. I know another mistake.
On the bottom I'm swimming about looking for scallops carring the scallop bag in my right hand. At frist I was keeping a good eye on my dive computer and air supply. However it is towards the end of the dive. My dive computer is telling me it is soon time to go as well is my air supply. If I remember right I'm a little cold now. 43 degrees F on the surface in only a wet suite is a little cold. It's getting hard to see my air supply gauge now, for its getting dark. And of course it was day light when I went in so take one guess where my flash light is. I will give you a hit not on me. I remember looking at my gauges and thinking it is time to go very soon. It was about at that time I seen a bunch of scallops so I had to get them. Now it is really time for me to go my computer is in the caution and my air is down to 500 and I'm still at 92 feet.
It's at this time I think I realize that I'm not scared but one could say a little nervous. I'm at 92 feet by my self air at 500, computer in the caution, a little cold, almost dark, and all for the very frist time.
I did'nt loose my cool I did not rush to the surface. I took my time comming up as I have always done before. As I'm comming up it starts to get a little lighter now. I like to watch my dive computer when I come up I look to see if the bars on the bottom of it are flashing telling me I'm comming up to fast. I don't think I have ever come up with out having them flash at least once on me. However I always stop let the bars stop flashing and then go on again.
Here is the kicker, and I bet alot of you know what I'm going to say. I did not make a decompression stop. Why not you ask? Well call it dumbness, forgetfulness, still a little nervous, or just plain old did not think I had to and this is why. Remember I took my OW and AOW back to back no dives in between. On both coures we never made any decompression stops. Even in the AOW on the deep dive to only 75 feet when we come up no stops were made. So only having used the dive tables a few times and not knowing them very well. As in remembering which depths I should make a stop at. Then buying all my gear another kicker spent over 5,000 with in a month and now don't know if I can use it. Any way I trusted my dive computer (which I now found out off the net that alot of people say they are no good) I was under the misconception that as long as the computer did not go into the red I did not have to stop. WRONG!!
So now I'm on the boat with in about five mintues I knew that there was some thing wrong. By 10 to 15 mins both legs and arms along with part of my neck went totaly numb. I could barly stand. It stayed like this all the way back to shore and until I got all my gear off. Kicker number 3 by the time I was ready to go home I was normal again, as if nothing had ever happened.
The other two divers were of course worried and one said that I should be going to the hyperbaric chamber. However by this time it is 10:30 pm the only chamber around is 4 hours away then plus time spent in the chamber well it add up to a long night. With the fact that I felt fine now and that we all thought the bends was pain in the joints and that was that. I managed to convince the other two I was good to go and so we all went home.
I got home and took a hot shower. I know (now). Then went to bed. The next moring the numbness was back but no wheres as bad as the night before. I spent the day a little worried about thinks but I guess due to lack of knowledge I did not know how bad things were. That night I went to the hospital at about 6:30 pm. They called the hyperbaric chamber told the doctor on call my simtoms. He said it sounds like I am border line send me home and he would call me in the moring. It is Thursday now the doc calls I tell him that I am no better. He says well a suspose that we should treat you come on up but there is no rush. By Thursday after noon I'm in the chamber for 5 hours. Nothing no change I went back the next day for 2 more hours, still nothing.
Today as I said before it is still my feet, legs, and lower rigt back that are numb. My right hand and arm are fine now. The night it happened I was numb it both legs and arms. However the next day my left arm was fine. I know that I used my legs for swimming but I also carried the scallop bag with my right hand. Is it because the muscles in those limbs were used more they got hit harder?
Any way I'm running out of time again I soon have to go. Even though this shows all the dumb mistakes I have made, and trust me I have been lectured a good many times about this. I hope it will be a good example of what not to do. mtdivegril I hope this has helped. Out of all this the two biggest things I have learned is. One ALWAYS ALWAYS make a decompression stop no matter how deep you were. And two if you ever think you are bent and the signs go away don't make the mistake of thinking that you are ok or that it will go away on its own get to a hyperbaric chamber.
The biggest KICKER of all I don't like the taste of scallops I was getting them for friends.
SAFE diving to all, perhaps with any luck one day I will dive again!!