Brennan  is a U.S. Army veteran whose exposure to battlefield medicine began in Iraq in 2005. In 2015, he established and managed the first team of combat-medics in Syria, conducted medical and combat operations, initiated and lead Tactical Combat Casualty Care (TCCC) training, and oversaw the procurement and logistics of Individual First-Aid Kits and trauma equipment.

Following his work in Syria,  Brennan began work with the U.S. government undertaking various missions throughout the Middle-East. In 2019, he expanded his experience in project, supply-chain, and quality management within the global medical device manufacturing industry.

Beginning in April 2022, Brennan brought this operational and technical experience to Ukraine, where he led medical support initiatives spanning training, evacuation planning, evacuation chain analysis, and medical equipment procurement and logistics. He organized TCCC and Prehospital Trauma Life Support (PHTLS) training and evaluated clinical workflows. He also established a quality assurance/quality control program for donated medical equipment, developed trauma-care systems, and provided instruction at Ternopil National Medical University.

Motivated by unmet needs in prehospital trauma care, Brennan founded Strategic Medical Systems—now known as Traumatec Systems—in October 2024. He has since engineered a modular hemorrhage-control platform, expanding its development to include sensing and digital communications technologies. His goal is to improve both immediate interventions and the coordination of casualty care, from the point of injury through definitive treatment. 

Above all, Brennan is a Christian, a father, a friend, and an advocate for those in need.