From the Editor: The Chambers of HBOT

  One of my earliest childhood memories is of a hyperbaric chamber and a birthday cake. My father was working at the School of Aerospace Medicine at what was then called Brooks Field Air Force Base, in San Antonio, Texas. The “space race” of the 1960’s was in full swing and scientists were working around the clock running the tests needed to put a man on the moon. For several days my father had been living in one of the research chambers and my mother and I brought him a three layer, home-made chocolate birthday cake. I was lifted up to the window to wave at him, and I watched in amazement as the cake collapsed in a heap as it exited the air-lock. This was my first demonstration of Boyle’s law.

  As the years went by I was to spend a lot of time in and around hyperbaric chambers working with my Father at the Texas A&M Hyperbaric Laboratory. We made mouse-size chambers for deep diving research out of thick oil field pipe. The “environmental system” for the mice was a heating pad placed on one outside wall of the chamber. When the mice were cold they leaned against the warm wall. In much larger chambers, using sheep, we performed research on the effects of diving and pregnancy.¹ I was a chamber technician and absolutely nothing was automated. Ascent rates were handled with stop watches and valves, which were turned by hand (“rightsy tightsy”). We mixed our own gas, did all our own plumbing, spent a lot of time putting soapy water on lines looking for telltale bubbles (leaks), and had an incredible collection of very big wrenches. We carried out record breaking experiments on both humans and large animals using hydrogen/oxygen mixtures, but even the human chambers were uncomfortable. You had to crawl into them and the windows were about 4 inches in diameter. Thankfully claustrophobia has never been a problem for me. However, by the late 1970’s and early 1980’s, as the funding and the emphasis on deep diving were diminishing and the interest in hyperbaric oxygen therapy was increasing, we began treating patients in these “diving” chambers. It was soon clear that far better equipment would be needed to administer hyperbaric oxygen therapy to debilitated people with limited mobility who probably would have a problem with claustrophobia. Over the ensuing years, chamber engineers and manufacturers met that challenge.

  Only a few months ago I visited Jeff Niezgoda at his beautiful facility in Milwaukee, featured in this issue. Although they still have the original cylindrical chambers made famous by Eric Kindwall’s pioneering work, they exist primarily as relics of the past. Their current patient facility is a walk-in, rectangular chamber, which blurs the lines between the exterior room and the hyperbaric structure, with comfortable seating and an entertainment system better than anything I have at home. The design of the entire facility picks up on the “hyperbaric theme” in a way that mixes 21st century technology with a soothing atmosphere. His facility is an example of how to design a clinic well. Steve Wood will discuss some pitfalls to avoid if you are planning a hyperbaric program. You can make big (and expensive) mistakes even beginning a small program, or turn a small program into a successful large one with the right planning.

  Monoplace (acrylic) chambers have also had an incredible evolution in the past 20 years. Automated controls, patient entry equipment, larger tube diameters and many other improvements have made them operator and patient friendly. Hyperbaric chambers of all types are also spectacularly safe. This safety record is thanks to very specific governmental regulations, excellent manufacturing standards, and the development of a “culture of safety” within each facility. However, it is a daunting thing to build a hyperbaric program from scratch. Just who are the chamber manufacturers and what are the differences between their products? What factors should you think about in choosing the chamber that is right for you? And what ancillary equipment do you really need? Steve Wood, with his many years of experience in the hyperbaric industry, brings clarity to these issues in his article on equipment.

  The real evolution has been in our understanding of the role of oxygen in the healing process. We once thought that the benefit of hyperbaric therapy was primarily the correction of hypoxia (excepting gas bubble disease, when we use Boyle’s law to crush intravascular bubbles like my father’s birthday cake). We now understand that HBOT can mitigate ischemia reperfusion injury. It also enhances the transport of certain antibiotics across the cell wall, activates growth factor receptors on the cell surface, and has many other activities we are only now beginning to understand.² It seems likely that the uses of HBOT will continue to expand as our understanding of its mechanism increases.³ That means that the need for hyperbaric programs is likely to increase. If you are considering adding or expanding a hyperbaric service, we hope this issue will provide practical guidance. I also hope that you can enjoy knowing you are part of the field which helped put men on the moon, break depth records in the sea, and continues to advance our understanding of human physiology.

Caroline E. Fife, Co-Editor of TWC, cfife@intellicure.com

References

1. Vascular Gas Embolism in Pregnant Sheep Following Simulated Compressed Air Diving, S. Brown, W.P. Fife, B. Long, in Women and Pressure: Diving and Altitude, ed. C. Fife and M. St. Leger Dowse, Best Publishing, 2010.

2. Physiology and Medicine of Hyperbaric Oxygen Therapy, ed. T Neuman and S. Thom, Saunders, 2008.

3. Hyperbaric Oxygen Therapy Indications, 12th edition, ed. L Gesell, UHMS, 2008. available at www.UHMS.org