Flying and diving?

[DEEP SEA]

It is an embossing question to ask but confusing to me. I have been diving for many years. In the past, maybe I have been lucky but I dove and jumped on a planes often. What is the real verdict? What can happen to you?

 

[Rick Murchison]

Here's the latest from DAN:
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"DAN Research is currently at work on the question of how long scuba divers should wait before flying after diving. The U.S. Navy tables recommend that you wait at least two hours before you board a plane after making a single no-decompression dive; the U.S. Air Force says you should wait 24 hours.
Current DAN FAD Recommendations

DAN's original recommendations for flying after diving based on maximum altitude exposure of 8,000 feet / 2,440 meters (the cabin pressure of commercial airliners) are:


A minimum surface interval of 12 hours is required before ascent to altitude in a commercial jet airliner (altitude up to 8,000 feet).
Divers who plan to make daily, multiple dives for several days or make dives that require decompression stops should take special precautions and wait for an extended surface interval beyond 12 hours before flight. The greater the duration before flight the less likely decompression sickness is to occur.
Current Research
Realizing that just about all current recommendations for flying after diving are based mostly on "best guess" and not hard data, Dr. Richard Vann and Dr. Wayne Gerth launched DAN's Flying After Diving study in 1993 at F.G. Hall Hypo/Hyperbaric Laboratory at Duke University Medical Center. The data so far suggest that the original recommendation of waiting 12 hours or more after making single no-decompression dives is reasonable.

In addition, current research suggests that it may be wise to wait 17 hours or more after making repetitive dives. However, the research is as yet incomplete and further work is continuing. More specific data on DAN's FAD recommendations are scheduled for a future issue of Alert Diver. The one unshakable truth is that the longer the surface interval after diving, the less the risk of DCS when flying afterward. Remember chamber trials are conducted within a relaxed, dry environment unlike the open water, where the multiple stresses of diving conditions may adversely affect the rate of inert gas uptake and elimination.

Extended surface intervals allow for additional denitrogenation and may reduce the likelihood of developing symptoms. For those diving heavily during an extended vacation, it may not be a bad idea to take a day off at midweek, or save the last day to buy those last-minute souvenirs."
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Rick

 

[Dr Deco]

Dear DeepSea:

Flying after diving is a very good question, and you should not at all be embarrassed to ask. Yes, possibly you were very lucky in your previous experience. Unfortunately, the answer of how long to wait between diving and flying is not known with any certainty. This is a complicated system with many parts; this much is known, however.

• Whenever there is a reduction of pressure, it is possible for micronuclei (= microbubbles) within your body to grow as dissolved nitrogen diffuses into them;
• You do not experience a large enough pressure change in an airliner cabin when you are saturated with dissolved nitrogen at sea level pressure, but this is not the situation if you have been exposed to increased gas pressure as encountered in diving;
• The greater-than-normal pressures of dissolved nitrogen from SCUBA diving can diffuse into micronuclei, and they can grow to cause decompression sickness;
• The gas loads can be estimated in the same fashion that they are calculated for dive tables, but you cannot estimate the size and number of tissue micronuclei.
• Because the number of nuclei (and gas loads) is variable from diver to diver (and can vary from day to day in the same individual), you can acquire DCS when flying following SCUBA diving even if you have not encountered problems earlier;
• It is therefore necessary to give yourself as long a duration as possible between the dive and the flight - - twenty-four hours if possible.
• Just as some people are more resistant to decompression sickness following diving, so are they more resistant when flying (= hypobaric exposure), but it is not easy to determine if you might be resistant to DCS.
• Therefore, just as you can get DCS even when within the table limits, you can also get DCS when flying after diving unless you tend to maximize the dive-fly interval.

The rules for diving and flying have not yet been developed by laboratory tests. DAN is working on this as mentioned above.

At NASA, we had the problem of astronauts working for six hours in a shallow pool of water (about 30 feet) at Marshall Space Flight Center (Alabama) and then wishing to fly back to the Johnson Space Center (Texas). We invested one year in this study of one time/depth profile, one surface interval, and one altitude. It is not an easy problem to solve!

 

[DEEP SEA]

Thank you Dr. Deco and Rick for a job well done. This is a topic that often plays on my mind since I dive and fly frequently. I try to give my self a day before flying especially after making multiple dives in a day. HOWEVER, when I am on a paid underwater video shoot, some director/producers have challenging schedules moving from location to location. Due to the fact they don't dive, they often do not think of the divers.

The information you guys supplied will definitely be something I plan to pass along in the planning phase of production so they can keep divers in mind.

Thanks again.

DEEP SEA