COMBAT Fellow Program Bios

Ian Eisenhauer is a PGY-4 resident physician at Denver Health Residency in Emergency Medicine and serves as a Senior Research Fellow at the University of Colorado Center for COMBAT Research.  After graduation from medical school in 2017, he completed an intern year in internal medicine, and then trained as an undersea and diving medical officer for the United States Navy. He supported a Naval Special Warfare diving unit and deployed out of Pearl Harbor, Hawaii with multiple roles as preventative, diving, and acute response physician during austere submarine-based missions. 

Ian returned to Denver in 2021 for training in emergency medicine and is a collaborator on research focusing on prolonged and prehospital care topics including hypothermia, issues with future maritime operations in a contested environment, and novel solutions to unresolved austere medical challenges. He is also active in mentorship and development of the CU COMBAT Fellows program, mentorship of CU COMBAT Scholars, and educational curriculum development.

John Hesling, MD is a graduate of the University of Colorado School of Medicine and fellow with the CU Anschutz Center for COmbat Medicine and BATtlefield (COMBAT) Research.

John served 11 years in the U.S. Navy as an F/A-18 Super Hornet pilot after graduating with distinction from the U.S. Naval Academy in 2008. He is a Navy Fighter Weapons School (TOPGUN) graduate and earned three Air Medals during combat operations in support of Operation Enduring Freedom in 2012 and Operation Inherent Resolve in 2017.

John's research characterizing Pediatric Supermassive Transfusion was published in the American Journal of Emergency Medicine. Additional research includes an assessment of Battlefield First Responders published in the U.S. Army Medical Department Journal and a F/A-18 tactical analysis published in the Naval Aviation Warfighting Development Center Journal.

John is completing his intern year in Internal Medicine at Saint Joseph’s Hospital in Denver and will complete his advanced residency training in Physical Medicine and Rehabilitation at the University of Colorado. He plans to pursue follow-on training in Interventional Pain or Interventional Spine.

Matt is a resident at the Denver Health Residency in Emergency Medicine and graduated from the University of Colorado’s Medical School in May 2023. Prior to medical school, Matt served as an Infantry Officer with the US Army’s 2nd Ranger Battalion and 10th Mountain Division. As a COMBAT Scholar and Fellow, his research interests focus on civilian and battlefield prehospital medicine. Matt has published 7 peer-reviewed manuscripts and has delivered 18 lectures and research presentations.

Matt founded a recurring Prehospital Trauma Lecture series which was featured in the Emergency Medical Minute podcast in 2023. He volunteers with the Three Rangers Foundation mentoring active duty Special Operations soldiers interested in transitioning to the world of civilian medicine.

LTC Steven G Schauer, DO, MS is an emergency medicine and critical care physician with the US Army and an anesthesia critical care medicine fellow at the University of Colorado School of Medicine. He has multiple combat deployments with both conventional and conventional operations forces.

Steven has a particular interest in scientific studies that advance airway management, resuscitation of patients in shock, and optimizing care delivered during the Role 1 phase of care.  He is an Associate Professor of Military and Emergency Medicine at the Uniformed Services University of the Health Sciences.

Dr. Branson Taheri was born in Denver, Colorado and grew up in Casper, Wyoming. After completing high school, he attended the United States Air Force Academy in Colorado Springs, CO and completed a degree in computer science.

Branson proceeded from the U.S. Air Force Academy to medical school at the Uniformed Services University of the Health Sciences in Bethesda, Maryland. While in medical school, Dr. Taheri developed an interest in vascular surgery while working with a research group focused on investigating technology used to manage hemorrhagic and vascular trauma in both military and civilian settings. Dr. Taheri was selected through the military match process to join the University of Colorado’s integrated vascular surgery residency while continuing on active duty in the U.S. Air Force.

Outside of work, Branson enjoys playing and watching ice hockey, going to baseball games, and skiing. Dr. Taheri is excited for the opportunity to train at the University of Colorado and to gain the experience and skills needed to succeed in a career as an Air Force vascular surgeon.

Ricardo I. Villarreal is a current resident in the Department of Psychiatry and is a part of the Brain and Behavioral Innovation Center for novel mental health therapeutics research. He completed medical school at CU SOM as part of the CU MSTP program. He received his PhD from the Department of Microbiology and Immunology where he completed his thesis on neural inflammation.

Ricardo has published research findings in various biomedical fields and participated in clinical research investigating novel field devices for early medical intervention for the U.S. Army. As a previous COMBAT Scholar, his research focused on firearm safety in military and community members within the scope of suicide prevention.

Currently, Ricardo continues to engage in suicide prevention efforts with the hope of incorporating novel technological approaches in high-risk populations targeting common mental health conditions.

Coco Wham, MD, MS is a resident at the Denver Health Residency in Emergency Medicine and graduated from the University of Colorado Medical School in 2024. Dr. Wham is also a firefighter paramedic and has worked in EMS since 2012. She continues to be engaged on the frontlines as an EMS lieutenant and firefighter paramedic for a rural agency. She is also an instructor for the Counter Operations of Narcotics of Terrorism Operation Medical Support Unit and has spent time with a tactical medical unit associated with the Department of Health and Human Services. 

Dr. Wham also recently developed a prehospital research consortium that consisted of data from 85 EMS agencies across the state and over 40 receiving hospitals to link prehospital care and patient outcomes. As a COMBAT fellow, her research interests focus on the modeling of civilian prehospital medicine to help inform battlefield prehospital medicine.

She has been featured on several podcasts, including EMS Cast, discussing her most recent peer-reviewed publication that analyzed the ability of end-tidal capnography to predict morbidity and mortality in a cohort of injured patients.