For most of us in hyperbaric medicine, our first love is, was - and always will be - diving medicine. The Memorial Hermann Center for Hyperbaric Medicine is the only multiplace chamber in Houston, Texas, opening its doors and seeing its first patient in 1989. One year later, I was recruited to The University of Texas Health Science Center at Houston and asked to develop a diving medicine program. Some of the first people in my office were safety officers from Gulf Coast commercial diving companies. That industry is very busy, and although commercial divers are usually recompressed offshore by their own companies, severe injuries still must be evacuated for further medical treatment.

Since Memorial Hermann Hospital is a major trauma center, our job is to coordinate the care of the other injuries that commercial divers often sustain, such as underwater blast, high-pressure water irrigation and crush injuries. A diving doctor must be on-hand to watch for signs of late-presenting decompression illness (DCI) while these other problems are being treated. And, in the case of severe neurological DCI, a specialist in diving medicine must become involved in the painful decision-making process of whether the diver can safely return to work.

As for sport scuba diving, given Houston's huge local diving community and the proximity of the Caribbean's beautiful diving destinations, Memorial Hermann Hospital became a major Divers Alert Network (DAN) referral center. When we hear the telltale sound of "now boarding" in the background, indicating that a diver is calling from the airport, we know we are in for a long night at the chamber. Also, with NASA just next door, we have developed chamber altitude capability that led to productive and important research, including a series of altitude experiments that helped decrease the time it takes astronauts to breathe oxygen before space walks, reducing their risk of DCI. Here again, the key element is oxygen. However, in scuba divers, we use oxygen to treat ischemia and speed resolution of bubbles after they develop DCI. In astronauts, we use oxygen before a space walk in hopes of preventing DCI by speeding the elimination of nitrogen from the tissues and thus preventing the bends from occurring while they are "decompressed" in the low-pressure environment of the space suit.

In many ways, the Memorial Hermann facility's growth has paralleled the growth of undersea and hyperbaric medicine. An explosion of information about the benefits of Hyperbaric Oxygen Therapy (HBOT) has led to a dramatic increase in interest in hyperbaric medicine, resulting in a need for better organization of both the medical and technical aspects of the field.

A New Physician Subspecialty
An ill-informed critic once called hyperbaric medicine a "treatment in search of a disease." At first glance, it is true that the list of maladies for which HBOT is felt to be proven beneficial is very diverse and ranges from decompression illness to crush injury. Of course, the common denominator is tissue hypoxia.

A day in the life of a hyperbaric physician is equally diverse, making it continually challenging and much deserving of specialized training. In the same weekend, we might treat an intubated patient with a necrotizing infection ("flesh eating bacteria"), a diabetic with a limb-threatening foot wound, a family of four with carbon monoxide poisoning from a faulty furnace, and a scuba diver returning from a vacation in Mexico. The diversity of these demands on hyperbaric physicians mandates specialized training and formal specialty recognition in order for the field to continue to grow. The Undersea and Hyperbaric Medical Society (UHMS) recognized this problem. Created in 1967, the UHMS is an international organization of physicians and scientists, with associate members who are nurses, technicians and other professionals, dedicated to education, research and training in the field of diving and hyperbaric medicine. The Society had already assisted with the development of the National Board of Diving and Hyperbaric Technology and the Baromedical Nurses Association Certification Board. Physicians had no similar mechanism for professional recognition.

The UHMS, working with the American Board of Preventive Medicine (and later the American Board of Emergency Medicine), succeeded in having Undersea and Hyperbaric Medicine recognized as a true subspecialty by the American Board of Medical Specialties, with the first examination November 8, 1999. Currently, 153 physicians have become certified through the examination process.

By 2004, it is anticipated that formal fellowship programs, approved by the American College of Graduate Medical Education, will replace the examination process, and physicians wishing to subspecialize in undersea and hyperbaric medicine will perform a year of fellowship training after completing their chosen residency. Thus, the undersea and hyperbaric physicians of the future will be prepared to handle the ever-increasing amounts of knowledge in this growing field.

Hyperbaric Facility Accreditation Process
The UHMS also recognized the issue of facility safety and quality. Questionable claims such as those by topical oxygen companies marketing their devices as hyperbaric chambers and touting them to be the same as whole-body hyperbaric chambers, as well as ads running in airline magazines for zip-up hyperbaric bags sold as a miracle cure for fatigue, are some examples of the need for regulation. The great interest in off-label use of HBOT for indications such as stroke and cerebral palsy, leading to rapid growth of freestanding hyperbaric facilities, is also of concern with regard to whether they are being safely run with proper physician oversight.

The UHMS played a key role in setting national standards relating to clinical hyperbaric chambers with the National Fire Protection Association (NFPA) and the American Society of Mechanical Engineers (ASME). However, there were no less than 16 different organizations, agencies and standards with ties to the practice of hyperbaric medicine.

The UHMS program, spearheaded by the organization's director of quality assurance and regulatory affairs, Tom Workman, MS, CHT, brought together these and many other standards that govern hyperbaric facilities, whether monoplace (single person, acrylic) or multiplace (multiple person, steel hull). While the survey process is voluntary, the objectives are to ensure that hyperbaric facilities are staffed with proper specialists who are well trained, using quality equipment that has been properly installed, maintained, and operated with the highest level of safety possible, and that facilities are providing the highest quality of patient care. This includes maintaining proper documentation of informed consent, patient treatment procedures, and physician oversight and involvement.

The result is a vigorous, grueling, two-day survey by a physician, a certified hyperbaric technician and a certified hyperbaric nurse, all three of whom are specially trained as surveyors. The survey encompasses all aspects of facility operations, such as administration, maintenance, facility construction, fire protection, patient assessment, care and education, quality improvement, information management, medical staff, teaching and publication, infection control, professional improvement and clinical research. The Memorial Hermann Center for Hyperbaric Medicine became the 11th facility in the United States to receive this accreditation by the UHMS on April 25, 2003. To date, 18 programs have been accredited in the United States since the program began in September 2002.

Putting It All Together
Perhaps the most important frontier in hyperbaric medicine right now is in the area of ischemia reperfusion (IR) injury. This also is likely to be of great importance in the field of diving medicine. While lack of blood flow (ischemia) causes tissue damage by itself, there is, ironically, a separate kind of injury caused when blood flow is restored (reperfusion). HBOT lessens the negative reperfusion effect in the brain and in the muscle, according to studies by Claude Piantadosi at Duke University, Steve Thom at the University of Pennsylvania, and Bill Zamboni at the University of Las Vegas. It is likely that this benefit of HBOT extends to the brain in the treatment of air embolism and neurological DCI.

As an example, we received a call in the past year about a commercial diver who was trapped underwater when his arm was sucked into a valve. Thanks to an innovative decompression profile suggested by Dr. Keith Van Meter of Tulane University School of Medicine and Louisiana State University School of Medicine, the diver was safely moved into a deck chamber where the valve was painstakingly sawed off during several hours of recompression. He was air-evacuated to our chamber in Houston where he continued to receive HBOT, not for DCI, but for ischemia reperfusion injury to his wrist and arm musculature.