Background: The high incidence of persistent postconcussion symptoms in service members with combat-related mild traumatic brain injury has prompted research in the use of hyperbaric oxygen (HBO2) for management.
Objective: The effects of HBO2 on persistent postconcussion symptoms in 60 military service members with at least 1 combat-related mild traumatic brain injury were examined in a single-center, double-blind, randomized, sham-controlled, prospective trial at the Naval Medicine Operational Training Center at Naval Air Station Pensacola.
Methods: Over a 10-week period, subjects received a series of 40, once-daily, hyperbaric chamber compressions at 2.0 atmospheres absolute (ATA). During each session, subjects breathed 1 of 3 preassigned oxygen fractions (10.5%, 75%, or 100%) for 60 minutes, resulting in an oxygen exposure equivalent to breathing surface air, 100% oxygen at 1.5 ATA, or 100% oxygen at 2.0 ATA, respectively. Individual, subscale and total item responses on the Rivermead Postconcussion Symptom Questionnaire and individual and total Posttraumatic Disorder Checklist–Military Version were measured just prior to intervention and immediately postintervention.
Results: Between-group testing of pre- and postintervention means revealed no significant differences on individual or total scores on the Posttraumatic Disorder Checklist–Military Version or Rivermead Postconcussion Symptom Questionnaire, demonstrating a successful randomization and no significant main effect for HBO2 at 1.5 or 2.0 ATA equivalent compared with the sham compression. Within-group testing of pre- and postintervention means revealed significant differences on several individual items for each group and difference in the Posttraumatic Disorder Checklist—Military Version total score for the 2.0 ATA HBO2 group.
Discussion: The primary analyses of between group differences found no evidence of efficacy for HBO2. The scattered within group differences are threatened by Type 2 errors and could be explained by nonspecific effects.
Conclusion: This study demonstrated that HBO2 at either 1.5 or 2.0 ATA equivalent had no effect on postconcussion symptoms after mild traumatic brain injury when compared with sham compression.
Physical Medicine and Rehabilitation Program Office, Department of Veterans Affairs, Washington, District of Columbia (Dr Cifu); Department of Physical Medicine and Rehabilitation, Virginia Commonwealth University, Richmond (Drs Cifu, West, Walker, and Carne); Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, Virginia (Drs Cifu, Walker, and Carne); Naval Medicine Operational Training Center, Pensacola, Florida (Dr Hart); and Richmond Defense and Veterans Brain Injury Center, Richmond, Virginia (Drs Walker and Carne).
Corresponding Author: David X. Cifu, MD, Department of Physical Medicine and Rehabilitation, Virginia Commonwealth University, 1223 E Marshall St, Richmond, VA 23298 (firstname.lastname@example.org).
Funding was provided for the primary study by a Defense Advanced Research Projects Agency grant (N66001-09-2-206), US Navy Bureau of Medicine and Surgery for contract funding temporary duty requirements, and the US Army Medical Materiel Development Activity for end-of-study contract funding. Dr Carne's and Dr Walker's efforts were additionally supported through a contract from the Defense and Veterans Brain Injury Center. The funding sources had no role in the study design, analysis, interpretation of the data, the writing of the paper, or the decision to submit the paper for publication.
The views expressed herein do not necessarily represent the views of the Department of Veterans Affairs, Department of Defense, or the US government.
The authors recognize and thank Ms Sheila Galvin, Traumatic Brain Injury Program Coordinator for the Wounded Warrior Regiment USMC, for her superb service in coordinating participant requirements; Ms Karen Guenther and the Injured Marine Semper Fi Fund, for transportation support for participants; Dr Jason Cromar, USAFSAM, for coordinating the protocol; the members of the Naval Aerospace Medicine Institute Hyperbaric Medicine Department, for supporting the 705 chamber dives and 139 man days of “bottom time” needed to complete this project; and Dr R. Scott Miller, US Army Medical Material Development Activity, Ft Detrick, Maryland, for manuscript review.
The authors declare no conflicts of interest.