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Undersea and Hyperbaric Medicine


Brian Keuski, MD#
Undersea and Hyperbaric Medicine Fellow
Duke University Medical Center

Ryan Snow, MD
Emergency Medicine Resident
Naval Medical Center San Diego

Christa A. L. Arefieva, MS
Texas A&M College of Medicine

John Hurley
Brody School of Medicine

Faculty Editor

Stephen Hendriksen, MD
Center for Hyperbaric Medicine
Division of Undersea and Hyperbaric Medicine
Department of Emergency Medicine
Hennepin County Medical Center

Special thanks to our 1st edition writing team

Chris Caravanos, MD
Stephen Hendriksen, MD


Description of the specialty
Undersea and hyperbaric medicine (UHM) is a unique subspecialty of emergency medicine that involves the therapeutic use of oxygen under pressure to treat disease. Hyperbaric oxygen is used to treat diving emergencies, arterial gas emboli, radiation injuries, complex wounds, carbon monoxide (CO) poisoning, deadly infections, ocular emergencies, and much more. The specialty of UHM includes treatment with hyperbaric oxygen but also the study of extreme environments, immersion effects, and marine life injuries.

The patient population is diverse, including recreational and commercial divers, patients requiring daily wound care, patients with complications after radiation therapy, and those who are critically ill. Fellowship training prepares physicians to care for patients with emergent and elective indications, participate in research, and become medical directors and leaders in the field.

History of the specialty/fellowship pathway
The history of hyperbaric medicine is long and storied. The first use of pressurized gas to treat medical disorders was recorded in 1662 by Henshaw. Decompression sickness, also known as caisson disease or “the bends,” was first described during the building of the Eads Bridge and Brooklyn Bridge in the 1860s. In the 1930s and 1940s, Behnke pioneered the first dive tables allowing for longer dives with increased safety for the diver. This foundation would be the beginning of what we now understand as hyperbaric medicine. Since then, many others have helped transform the field from one of observation and anecdote to the evidence-based use of hyperbaric medicine today. The American Board of Emergency Medicine began board certification for UHM in 2000. The indications for hyperbaric oxygen therapy are published by the Undersea and Hyperbaric Medical Society (UHMS).

Why residents choose to follow this career path
Hyperbaric medicine is an exciting field that gives the emergency physician a new and powerful tool. Further, for those with interests in diving, wound care, or extreme environments, this is an incredibly useful skill that can help patients in and out of the emergency department. The field of UHM is growing, treatment indications are expanding, and there are many research opportunities available. Fellowship training will help you become a leader in undersea and hyperbaric medicine.

How do I know if this path is right for me?
If you love the pace of emergency medicine and resuscitation, have an interest in diving and physiologic effects of high pressure environments on human tissue, and love teaching and expanding the body of medical knowledge in which you have found your niche, then hyperbaric medicine may be the right path for you. 

Career options after fellowship
The career options are broad and diverse, including practicing at dive clinics, hyperbaric tertiary referral centers, hyperbaric wound care facilities, commercial dive-related careers, and classic emergency medicine. Employment facilities can also be varied, with large multiplace chambers (multiple chambers connected, able to treat many patients at one time) that may be more focused on hyperbaric treatments, monoplace chambers (single person chambers) with an emphasis on wound care, or academic centers that have hyperbaric/hypobaric chambers and may be more focused on research into extreme environments.

Splitting time between departments
Many UHM careers are a mix of emergency medicine, hyperbaric medicine, and wound care, and it’s important to find the right balance.

Academic vs. community positions
Fellowship training would be highly advantageous if you desire to stay in academia, although many fellowship trained hyperbaric physicians continue to practice in the community and become medical directors of their facility.


Number of programs
There are presently 7 institutions offering fellowship programs accredited by the Accreditation Council for Graduate Medical Education (ACGME) and one which is a DO only program:

Several fellowship programs are in the works and upon publication of this guide may be active at the following locations:

  • University of Texas Southwestern, Dallas, TX
  • Intermoutain Healthcare, Salt Lake City, UT
  • Aurora Health Care, Milwaukee, WI

Differences between programs
Programs vary in the time fellows spend on call, time spent in wound care clinic, amount of critical care experience, and didactic requirements. Some programs place emphasis on hyperbaric medicine for wound care whereas others have a stronger diving medicine curriculum. All programs guarantee ample exposure to traditional and innovative applications of hyperbaric technology. 

Length of time required to complete fellowship 
The fellowship is one year with time divided between the clinical experience, participating in research, attending national conferences, and allotted vacation. Most institutions have allowance for one to five fellows however this can vary between programs and with year-to-year funding of the institution.

Skills acquired during fellowship
Fellowship programs include a diverse range of clinical responsibilities along with research requirements. All fellowships prepare candidates to treat emergent and elective patient indications for hyperbaric oxygen therapy. The fellowships also teach participants occupational and environmental safety standards, the clinical aspects of diving medicine, and hyperbaric chamber operations.

Typical rotations/curriculum
Fellows are responsible for managing elective and emergent patients receiving hyperbaric treatments in the chamber, completing consults, attending didactic sessions, and gaining basic understanding of hyperbaric chamber operations and management. It is not uncommon for an emphasis on wound care to be part of the hyperbaric fellowship curriculum. On-call time is built into schedules where fellows will respond to emergent hyperbaric treatment indications. Fellows typically attend one or more conferences related to the field throughout the year. Most fellows attend the NOAA Physicians Training in Diving Medicine course, held in Seattle, WA in October and the UHMS Annual Scientific Meeting (ASM) held in June.

Board certification afterwards?  
UHM is an ACGME-accredited fellowship. Board certification in UHM is available after completing the fellowship. This certification covers the individual for a period of ten years upon which they will need to re-certify in order to continue working within UHM. 

Average salary during fellowship
Salary is typically based on a PGY-4 (or 5) contract.


How competitive is the fellowship application process?
Programs report the selectivity for applying residents as moderate to highly competitive. 

Requirements to apply
Candidates must have completed an ACGME-accredited training program and be board eligible/board certified in their specialty. Emergency medicine (EM) training is common among most applicants, though other specialties are able to apply including surgery, anesthesiology, emergency medicine, internal medicine, preventative medicine, neurology, pediatrics, and family practice. Additionally, applicants must hold a valid medical license in whichever state they will be attending the fellowship. 

Research requirements
Research is not a requirement for applying to fellowship but will improve your chances of being offered a fellowship position. 

Suggested elective rotations to take during residency
If your residency institution has a hyperbaric center, it is recommended to rotate through to gain experience. Also, scuba diving certification is not a pre-requisite for the fellowship, but it may be encouraged at some point before or during training. 

Suggestions on how to excel during these elective rotations
To excel, read current literature on hyperbaric medicine, get involved with your seniors and faculty members during cases, and take initiative when it comes to exploring research and case report opportunities. 

Should I complete an away rotation?
Away rotations are not required, but will certainly help make you more competitive. 

What can I do to stand out from the crowd?
Research in hyperbaric medicine, case report publications, talks given at local and national conferences, as well as service to the field of undersea and hyperbaric medicine are great ways to demonstrate interest and set yourself apart from other applicants. 

Should I join a hospital committee?
This is not required, but it is encouraged to demonstrate interest and open new opportunities for yourself. 

Publications other than research
Case reports, articles in magazines and websites dedicated to UHM, and review articles are other great ways to publish in the specialty. 

How many recommendations should I get? Who should write these recommendations?
Most programs require at least 2 letters of recommendation. Recommendations should come for senior hyperbaric faculty and from your program director. Ensure that you thoroughly research the program for specific requirements.

What if I decide to work as an attending before applying? Can I still be competitive when I apply for fellowship?
Attendings who have been practicing and are looking to further develop their careers are welcome to apply and are competitive for fellowship. 

What if I am a DO applicant?
Graduates of MD and DO granting medical schools will be considered as long as residency has been completed and licensing has been achieved. 

What if I am an international candidate?
International applicants are also welcome to apply provided they meet licensing requirements.


How many applications should I submit?
Apply broadly, as there are limited slots for fellows and few programs nationally. Also, ensure that you are able to obtain a medical license in that state for which you are applying. 

How do I pick the right program for me?
As with residency application, the “right” program will be based on personal and professional preferences. 

Common mistakes during the application process
A common mistake is to apply later in the year (September or October), when most of the positions have already been filled. 

Application deadlines
There is no match for UHM, most programs use a rolling admissions process. Start applying  early (usually July or August of the year prior to starting fellowship). Interviews typically run from August through December, but candidates can contact programs earlier. Occasionally programs do not fill all their spots or spots will open, so it is never too late to contact programs to ask if applications are still being accepted. 

Tips for writing your personal statement
The personal statement is a key part of the application. Your statement should demonstrate basic knowledge of the field, address why you want to enter the field of hyperbaric medicine, and what you plan to do in the next 5-10 years. 

Is this a match process?
No. Applications are sent directly to the programs. 

What happens if I don’t obtain a fellowship position?
If you do not obtain a fellowship you can reapply, though it may be more difficult to obtain a fellowship offer the second time around. If you do not receive an offer, it is recommended that you continue to work clinically while exposing yourself to hyperbaric medicine and stand out by doing research, joining committees, and getting involved in other ways.


How do I stand out from the crowd?
It is essential that you come prepared. Read up on the program and latest topics in hyperbaric medicine. Obtain information specific to the program at which you are interviewing so you have a general understanding of the fellowship training offered by the program. As with any interview, the interest in that position should not start upon acceptance. Rather the individual should already be engrossed in UHM research, clinical work, and aware of the future of the field and that particular program. Be sure to have questions prepared and have a strategy in place that allows you to emphasize your most appealing attributes. Arrive on time, be polite, and be interested. Be prepared to answer the question: “Why do you want to do a hyperbaric fellowship?” 

What types of questions are typically asked?
Interviewers will ask you why you want to go into hyperbaric medicine and ask you pointed questions about current topics in hyperbaric medicine as well as questions regarding items in your CV and application. 

How many interviews should I go on?
Given the limited number of programs, you should accept all interview offers in order to improve your chances of being offered a fellowship position.


Textbooks to consider reading

  • Neuman T, Thom S. Physiology and Medicine of Hyperbaric Oxygen Therapy. 1st ed. Philadelphia, PA: Saunders and Elsevier; 2008.
  • Edmonds C, Bennett M. Diving and Subaquatic Medicine. 5th edition. Boca Raton, FL: CRC Press; 2015.
  • Weaver LK. Hyperbaric Oxygen Therapy Indications. 13th ed. North Palm Beach, FL: Best Publishing Company; 2014.


Important skills to practice while in residency to prepare for fellowship
Become well-versed in the indications for hyperbaric therapy and gain general knowledge regarding chamber function and diving. The pursuit of diving is not a requirement however experience in the field will be appreciated. Coupled to that should be familiarity with principles of wound care and management using hyperbaric medicine. 

Tips on how to succeed as a fellow
Fellows must be committed to the specialty. This means being professional, invested in your work, and willing to contribute to the community of your specialty. 


Additional resources


  • Undersea and Hyperbaric Medical Society (UHMS) Journal
  • Diving and Hyperbaric Medicine Journal

Online seminars

National organizations


  • UHMS Annual Scientific Meeting in June
  • ACEP UHM Section annual meeting at ACEP Scientific Assembly

How to find a mentor
Prior to fellowship, contacting your local hyperbaric chamber to talk about careers in hyperbaric medicine would be valuable. A week to month-long rotation at a hyperbaric chamber, or becoming involved in hyperbaric medicine research projects, would also be helpful.

# The views expressed in this chapter are those of the author and do not necessarily reflect the official policy or position of the Department of the Navy, Department of Defense, nor the U.S. Government.

I am a military Service member. This work was prepared as part of my official duties. Title 17, U.S.C., §105 provides that copyright protection under this title is not available for any work of the U.S. Government. Title 17, U.S.C., §101 defines a U.S. Government work as a work prepared by a military Service member or employee of the U.S. Government as part of that person’s official duties. 

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