flying after diving- a question

[cscartwright69]

I would be interested in thoughts on how long gas, and/or bubbles stay in the body after diving, having read a lot of posts on the 24 hour FAD debate.

I recently flew back from a dive trip in Africa leaving 5 days between my last dive and flight.

After my final dive, I had a slight ache in my right arm but my divemaster was convinced this was not due to DCS due to the conservative diving I had done. so I had some O2, left it 5 days and did not get recompressed. on the flight home, I experienced numbness in my hands and feet and went immediately to a chamber when I landed. (symptoms partially resolved and dive doc now believes not worth doing another session as the nerve damage will heal).

anyway back to my question - I had not thought it possible that has would still remain in the body 5 days after a dive, but if there was no has left in the body, why did I experience problems on the flight?

apologies if these queries are naive - am no expert. but thoughts welcome.....

 

[Dr Deco]

Hello cscartwright69:

Delayed DCS

I have always been suspicious of long delays. Normally, a stabilized free-gas phase in the body would not be considered possible because of the internal, Laplace pressure on the gas in the bubbles. However, God and Nature might play a different game.

The recent abstract below (September, 2003) indicates that DCS problems might “lurk below the surface” for some time. Exactly how all of this might occur is definitely unclear.

Nonetheless, this individual experienced a minor decompression (probably leading to an embolism) that did not resolve with time. Clearly, not enough of the blood supply was compromised so that the neurons were left in a so-called “idling” mode [in the penumbral region].

This answer is pretty hazy, I know. Just one of life’s little mysteries.

Dr Deco :doctor:

Abstract :book2:

Hickey MJ, Zanetti CL. Delayed-onset cerebral arterial gas embolism in a commercial airline mechanic. Aviat Space Environ Med. 2003 Sep; 74(9): 977-80.

A commercial airline mechanic was evaluated for right-sided hemianesthesia (numbness). Thorough diagnostic testing failed to identify a definitive etiology, and the mechanic was assessed as having symptoms of a left internal capsule lesion [portion of the brain], likely from an ischemic event. On day 12 after symptom onset, he consulted a diving medicine specialist for clearance to continue recreational scuba diving. A thorough history revealed that the patient worked regularly in a compressed air environment of commercial aircraft and had experienced a rapid decompression approximately 48 h prior to onset of the hemianesthesia. The specialist considered pulmonary barotrauma-induced cerebral arterial gas embolism as a possible diagnosis. On day 13 he was treated with hyperbaric oxygen using Treatment Table VI, which produced immediate relief. Following three additional hyperbaric oxygen treatments in the next 11 days, he reported nearly total resolution of his symptoms. This occurrence is believed to be the second report of a cerebral arterial gas embolism in an aircraft mechanic or maintenance crewman and suggests that the latency between time of depressurization and the development of symptoms from a pulmonary barotrauma-induced cerebral arterial gas embolism may extend longer than previously believed.

 

[cscartwright69]

thanks Dr Deco.

I am due to fly again in 2 weeks - in your opinion, should I avoid doing so given this example? Or is is crazy to assume I would have any gas still in my system 20 + days after my last dive?

thanks again for your input.

 

[Dr Deco]

Hello cs:

Since many divers will travel by air following diving, and DCS, I would continue with your travel plans. If DCS should reappear during your diving, I would not reboard until that is taken care of by recompression therapy.

Should this problem appear again, I think that diving and air travel are not a good combination for you. :tree:

Dr Deco :doctor:

 

[pipedope]

breathing O2 before the flight for a bit more safety factor?

 

[mwilding]

pipedope once bubbled...
breathing O2 before the flight for a bit more safety factor?

a pressurized tank of o2 might not be too welcome at the security checkpoint though..

 

[DawgPaddle]

I'm a pilot myself and have always been overly-cautious about flying after diving. I usually give it 3-4 days before taking off. Even in smaller single engine aircraft, you can easily climb at 500 feet a minute. If fact, climbing the aircraft at 500 feet a minute is the minimum climb-rate for some types of flying. For this simply reason, I've yet to fly myself to a dive destination. Perhaps too cautious, but I figure better safe than sorry.

 

[BigJetDriver]

Hi, all!

I hope everyone had a very Merry Christmas, and a happy (and safe) New Year's celebration.

I was headed back across the pond a couple of days ago and thought to pull up the synoptic page for cabin pressurization. We were at 37,000 feet msl just to the south of Greenland (which is not), and the cabin pressurization was at 6,300 feet msl. It had, of course, been at that level for some hours since we were at mid-point on the North Atlantic Track system.

I was thinking that it is hard enough on the body to go from sea level to that altitude and remain for hours. How much harder would it be if I had been diving with some of my friends over in jolly old Blighty!

The story reported by Doc Deco in his post, and the one that started this thread, from C. S. Cartwright, should make us realize that, when it comes to the human body and decompression practices, absolutely NOTHING is clear-cut.

The recommended procedures that we have, such as NOAA's, are like the Pirate's Code (i.e. more of a set of guide-lines, really)! We have to come to some realistic assumption of personal risk. For most of us, that will hopefully fall somewhere between the total paralysis of not being able to get home from our dive destination by air, to the insanity of something like MHK's "deco till you drop and fly with your hair wet" policy.

As part of our personal assumption of risk, we have to recognize the fact that there will always be cases of excursion from the statistical norm, and we may BE that excursion even when we follow conservative and accepted recommendations from agencies such as NOAA and leading researchers such as our own Doc Deco.

As Tom Mount puts it: "Everyone has the right, once INTELLIGENTLY INFORMED of the risks, to risk himself or herself as he or she sees fit!" (For those of you who know Tom, you know I've cleaned that one up a lot!) The keys to that one are, of course, having a good understanding of the parameters of the risk-situation, and then applying good judgement. Here we are indebted to such people as our Doc's Deco, I. G. Saturation, Vikingo, and Stein for their willingness to lend us their hard-earned knowledge and experience, to hopefully keep us in the "safe zone" of our diving and FAD practices.

Cheers, and happy diving (bubble or not) in the New Year!

BJD :anakinpod

 

[BigJetDriver]

As an addition to my above post, the NOAA table from the NOAA Diving Manual, current edition, is probably the best and easiest "guideline" to use. You can order one from Best Publishing.

BJD :anakinpod

 

[BigJetDriver]

Sorry about the further afterthought, but you may be familiar with the on-going DAN FAD study. They are doing chamber tests currently which, no doubt, will bring about some dramatic changes in the FAD guidelines. It will be quite some time before the results can be tallied, analyzed, and published, so, as they say, don't hold your breath. Until that time, a reasoned and common sense approach based on the NOAA guidelines would seem to be the best procedure.

Cheers! :anakinpod