1. Department of Orthopaedic Surgery, Naval Medical Readiness and Training Center Portsmouth , Portsmouth, VA 23708, USA
2. Department of Anesthesia, Naval Medical Readiness and Training Center Portsmouth , Portsmouth, VA 23708, USA
3. Department of Anesthesia, Vanderbilt University Medical Center , Nashville, TN 37232, USA
4. Department of Plastic and Reconstructive Surgery, Walter Reed National Military Medical Center , Bethesda, MD 20814, USA
5. Department of Obstetrics and Gynecology, Naval Medical Readiness and Training Center Portsmouth , Portsmouth, VA 23708, USA
6. Department of Surgery, Naval Medical Readiness and Training Center Portsmouth , Portsmouth, VA 23708, USA