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MAST Again: Medical, Not Military Anti-Shock Trousers

Read Bledsoe’s March Column: The MAST Will Not Die

Photo courtesy of Bryan BledsoeThis will be my last tirade on MAST. In my last monthly column, I had a fairly detailed overview on the MAST. Like many things in EMS, discussions of MAST bring out an emotional response from many of us who used the device in the 1970s and 1980s. And for this reason, the issue is worth revisiting.

MAST discussions tend to bring the usual comments about the “Houston study” being flawed and a constant reminder of how many lives MAST saved in Vietnam. Everybody knows that MAST saved many a life in Vietnam, right? Guess what? MAST were not used in Vietnam (except for a small field study). Here, too, is another EMS urban legend that must give up the ghost.

MAST were designed by the National Aeronautics and Space Administration (NASA) in the 1970s. They were part of a congressional mandate to assure that civilians derive something of value from the billions of dollars spent annually on the space program. MAST were a derivative of the G-suit worn by fighter pilots. At NASA, they were primarily used for physiological tests on astronauts as they prepared for their trips to space. A press release from NASA stated, “The anti-shock trousers are an adaptation of the anti-gravity flight suits originally developed for pilots and astronauts. They were modified to combat internal bleeding in trauma victims in emergency situations.”1

As I answered several queries to last month’s article, I went back to all of the original research on MAST. I could find no evidence that MAST were used in Vietnam with the exception of a small field study. That study, conducted in 1969, did not involve MAST per se, but involved actual “G-suits” used by pilots of high-performance aircraft. The study had a cohort of eight patients (four Americans and four Vietnamese) ranging in age from 18-24 years. Of the eight patients, seven survived evacuation, but only four eventually survived.2

I looked and looked and even requested several books via interlibrary loan. I could not find one picture or one mention of MAST in Vietnam. Finally, I decided to call an expert. In fact, I called THE expert: Colonel Warner D. “Rocky” Farr. Rocky is a friend and the Command Surgeon for the United States Special Operations Command (USSOCOM). I co-chair the Certification and Evaluation Board (CEB) for all Special Forces medics through USSOCOM (thus, how I got through to the colonel). In addition, Rocky is a military historian and was a medic in Vietnam before he attended medical school.

He stated, “I never saw MAST pants in the People’s Republic of Vietnam. They came in during the late 1970s as a part of ATLS (Advanced Trauma Life Support). There was one study in JAMA and they were used occasionally in the post-Grenada invasion.”3 For those of you too young to remember, the Vietnam War ended April 30, 1975 (before MAST were made).

There. That’s it. Breathe in, breathe out, move on. MAST were NEVER Military Anti-Shock Trousers -- they were Medical Anti-Shock Trousers. They were developed by NASA and first manufactured by the now-defunct EMS manufacturer Dyna-Med. They had some sporadic use in the military — but not during wartime.

It is amazing to me how these stories develop and spread. We know why R. Adams Cowley made up the “Golden Hour.” He had to sell his multi-million dollar shock trauma center (and assorted helicopters) to the Maryland legislature and the people of that great state. Because Cowley was so well-respected, the concept was bought “lock, stock and barrel.” Even now that we know the “Golden Hour” is a myth, people are still reluctant to give it up. In the most recent edition of our five-volume paramedic textbook series, borrowing from PHTLS, we now use the term “Golden Period.”4 That is about as nebulous as you can get. Why people had to embellish the life and times of MAST in Vietnam is and will forever be a mystery. I guess it made for good night time station stories.

I promise I will leave MAST in the old cabinet in the back of the station where they have been for the last 15 years. But this has been an interesting study of how we EMS people embrace and refuse to give up something as boneheaded as the Medical Anti-Shock Trouser. When I get time, I will detail how I saw a chicken come back to life with only the music from an accordion as intervention. Maybe I need a debriefing…


1Available at: http://www.sti.nasa.gov/tto/spinoff1996/28.html (Accessed April 14, 2008).
2Cutler BS, Daggett WM. Application of the “G-Suit” to the control of hemorrhage in massive trauma. Annals of Surgery. 1971;173:511-514.
3Personal communication. Colonel Warner B. “Rocky” Farr (April 14, 2008).
4Bledsoe BE, Porter RS, Cherry RA. Paramedic Care: Principles and Practices, Third Edition. Upper Saddle River, NJ: Brady/Pearson Education, 2009.

EMS1.com columnist Bryan E. Bledsoe, DO, FACEP, EMT-P is an emergency physician, paramedic and EMS educator. Dr. Bledsoe is the principal author of the Brady paramedic textbooks and others. He has more than 20 years publishing experience and has more than 900,000 books in print and has written more than 400 articles.
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