STAFF
Marlow Macht, MD, MPH, FACEP (Medical Program Director)
Dr. Macht is board-certified in Emergency Medicine and Emergency Medical Services (EMS). After working for eight years as a wildland firefighter, he graduated from paramedic school in 2000 and spent four years working as a paramedic for the City and County of Denver before attending medical school. He earned his medical degree and a Master of Public Health from Tulane University. He then returned to Denver, where he completed a residency in Emergency Medicine and a fellowship in Emergency Medical Services.Dr. Macht has been in Clark County since completing his training in 2013. In addition to serving as the Medical Program Director, he practices emergency medicine at Legacy Salmon Creek Medical Center.
Marc Muhr, Paramedic (Program Manager)
Marc is a paramedic with 34 years of experience. After graduating from Linfield University with a bachelor’s degree in athletic training and health education, he completed the advanced paramedic education program at Oregon Health & Science University in 1990. He began working as a paramedic in Portland and Vancouver, became a field training officer in 1990, and was appointed Regional Training Officer for American Ambulance the following year.
In 1994, anticipating the expansion of the initial exclusive ambulance franchise model, Marc began working with the county’s Medical Program Director at the time, Dr. Lynn Wittwer. He now works with the current MPD, Dr. Marlow Macht, following Dr. Wittwer’s retirement. Marc is honored to have been part of a high-functioning EMS system throughout his career.
Lynn Wittwer, MD, MS, FACE (ret.) (MPD Emeritus)
Dr. Wittwer served as the Clark County MPD from 1982 to 2024. He graduated from the University of Oregon Medical School, Class of 1967 (pre-OHSU). Board certified in both Emergency Medicine and Family Medicine, he had been an Emergency Physician in Vancouver since 1977 and served as the Medical Director of the Emergency Department at Southwest Washington Medical Center for 30 years. He held several leadership positions within the Washington Department of Health EMS system, including Chairman of the State MPD Council, Chairman of the Licensing and Certification Committee, and Member of the EMSTC Steering Committee.
Since retiring in December 2023, he has continued to serve as an advisor to the Clark County MPD on state and county EMS issues and history.
Shreena Narend, Data & Operations Specialist
Shreena is the Data and Operations Specialist. She holds a degree in Biology with an emphasis in Neurobiology from the University of Oregon and later earned a degree in Chemistry from Portland State University. During her undergraduate studies, Shreena obtained her EMT certification and CPR instructor credentials. She also volunteered on the Neuro Rehabilitation floor at PeaceHealth in Eugene, assisting patients with spinal cord injuries. Her professional experience includes working as a Medical Scribe and Clinical Chart Auditor in Emergency Departments across Portland and Vancouver. Additionally, she volunteered as a Public Health Educator at the Oregon Poison Center, where she eventually joined the staff as a Public Health Educator and Quality Improvement Specialist. Shreena is enthusiastic about beginning her journey with Clark County EMS and looks forward to contributing to the team's mission.
Consultants
David Castillo, PharmD, BCPS, BCEMP (Pharmacist)
David Castillo is a double board-certified pharmacist specializing in Pharmacotherapy and Emergency Medicine. With over a decade of experience in trauma centers and ambulatory care, he currently leads Emergency Department pharmacy services at PeaceHealth Southwest Medical Center, where he’s pioneered workflow innovations and expanded clinical programs. A dedicated educator, David has delivered 40+ presentations, precepted trainees, and supported academic programs to advance pharmacy practice and patient care. In 2024, he founded EMRx Solutions, a pharmacy consulting company created to share best practices and help healthcare teams address complex pharmacotherapy challenges through practical, evidence-based solutions.