BENT

{Shit Happens} He smoothed down his lapel. "I always wear this pin at decompression meetings" Dr. R.W. Bill Hamilton, NAUI ICUE 9OCT92.

With little metaphoric license, decompression illness could be easily labeled the "sexually transmitted disease" of sport diving. Like STDs, the affliction strikes divers engaged in an activity that is fundamental to their nature. What's more is that there is a disproportionate fear and stigma surounding DCI suggestive of "moral disease," and a surprising lack of understanding regarding the disorder, on the part of divers and the industry as a whole.

Though the origin and cause of this phenomena is complex, the situation is not unique to sport divers. In fact the need to "decriminalize" DCI, a subject dealt with in a recent U.S. Airforce workshop, has been a long standing issue in scientific, commercial and government diving, as well as aviation. As summarized by one astronaut at the workshop , "Reporting DCI is not exactly a career enhancing move."

This inability or unwillingness to face the facts is the real danger surrounding decompression illness, and in the case of technical diving, an obstacle to its potential growth and development. In order to improve safety&endash; one of the fundamental objectives in technical diving&endash; we need to be able to straight in our approach to DCI and remove its associated stigma and fear. Perhaps the first hurdle is better recognition of the statistical nature of decompression itself.

The "popularized" Haldanian view of the world held that DCI was deterministically predictable, that there were absolute limits. One side of the line represented safety, on the other DCI. Though this view persists, perhaps in part, for the convenience of teaching, it has long been known this is simply not true. Haldanian algorithms work with an "acceptable" degree of reliability because they are calibrated to real world data&endash;"what works, works." Today leading research has shifted to statistical modeling pioneered by individuals like Paul Weathersby, Shalini Survanski, Ed Thalmann, Hugh Van Liew, Richard Vann, Bruce Wienke and others.

Alluded to by Dr. Hamilton's decompression pin, the view today is that DCI is not an accident. It happens and will continue to happen as a predictable part of diving. No significant dive is free of the risk of decompression illness, and it is generally acknowledged, that the risk on some of today's technical-level exposures may be high. Richard Vann, Duke University (see "Decompression Safety" pg. XX) estimates the overall sport diving incident rate to be about 0.02% or about "one incident in 5000 dives." Given that the risk for some technical-level dives could reasonably be as much as 5-10 times greater, or "one incident in 500-1000 dives (an incident factor of 0.1-0.2%)," it is likely that most technical divers will get bent at least once in their diving career and probably more. Again quoting Hamilton, "It's just like being a cowboy. If you ride a horse enough times you are going to get thrown. Expect it and be prepared to climb back on."

Given that DCI is and will remain an integral part of technical diving (and diving in general), what should be done? There are several competing approachs to work from. The unspoken recreational "weltanschauung," might be summarized as follows; DCI is a result of violating the limits (see "Straightening Out The Bends" pg. XX) and in most cases means an end to the individual's diving career. The few hapless victims of "undeserved" DCI represents an unfortunate fluke. The problem is that this view is not very accurate or useful. In contrast, the approach taken by the commercial world seems more applicable to technical divers and potentially more fruitful. In the commercial world, DCI is an expected occupational hazard, part of the job, and if treated immediately (and properly) the consequences can be reduced to near zero making it more of a painful inconvenience&endash;shit happens&endash; that a life or career threatening ordeal.

The solution for the technical community is to expect and plan for DCI and be prepared to deal with it. Though efforts like the D.A.N.'s field oxygen administration are an excellant beginning, more is needed. Author Bret Gilliam recently compared the situation to staging a highschool football game, "It would be stupid and irresponsible on the part of a coaching staff to not be prepared to treat injuries." Ouch. More specifically, in a recent editorial in the Associated Dive Contractors (ADC) magazine, "Underwater," editor Cavett Hughes observed that technical diving was "severely deficient" in most of the basic consensus safety principles established by the ADC. She went on to illustrate her point by way of example, correctly and incredulously pointing that , "many of these deep dives have been done not only without a chamber on site, but often hours away (italic&endash;ed.).

Historically the move to onsite chambers has been consciously resisted both by the sport and scientific diving communities on the basis of demonstrated need, the economics involved, loss of operational flexibility and in the case of some sport operators, the belief that providing "topside support" in general, and an onsite chamber specifically, would increase assumed responsibility and therefore liability. These factors appear to have been some of the initial hurdles that were faced in getting chambers installed at diving resorts, which has now become common practice.

Interestingly this world order is changing with the promulgation of the technical diving movement, and the development of new methods and technologies. Rather than by decree from government or other regulatory agencies (which should and would be fought "tooth and nail" in any account) this changeover may be a more a function of technology and its associated economics.

In-water oxygen therapy (see "In-water Recompression," pg. xx) appears to be a promising, though perhaps transitional, solution to the problem of field treatment for technical divers. Though historically, in-water recompression has suffered from significant stigma where recreational diving was concerned, and is not without legimate risk, much of this can be traced to the lack of knowledge, training, experience and equipment on the part of the recreational community. Though it will take some work to properly implement on a widespread scale, the technical community doesn't suffer from the same limitations as its "mass market" counterpart; in-water oxygen decompression is a standard practice, divers generally have adequate thermal protection (dry suits) and the proper equipment to implement in-water therapy is readily available.

Probably the most exciting news is the development of Kevlar-based portable chambers being pioneered by the U.K.'s SOS Ltd (see "Portable Chamber Technology, " pg. XX, tek.GUIDE). Priced at around U.S.$30,000, the prospect of conducting a Doria dive with an onsite chamber on board seems less remote, and given the nature of beast, quite appealing. What's more is that there is at least one other U.S. company in the wings which is reported to be rolling out a new portable this year priced in the U.S.$18,000 range&endash;about the cost of outfitting two technical divers, if you include their scooters. Gulp.

Will onsite chambers become the future "community standard" for technical diving? Perhaps the more relevant question is; who would you rather be diving with; "the haves" or the "have nots?" With regards to assumed liability, it is not unlikely that the issue may eventually be reversed, "You conducted this operation without a chamber?" Unrealistic? Just consider the hypothetical outcome of a court case today involving an technical operator who conducted a 300 fsw (92 msw) guided wreck dive on "air."

The "bends" remains a formidable issue in the development of technical diving if our objectives of improving safety are to be met. Perhaps the first step is simply to get it out in the light of day so that we can examine it better. That's what this issue of aquaCorps is all about.

Michael Menduno

3JAN93