top of page

DFES Board of Directors

Concrete Wall

Len Nitowski, MD


Leonard A Nitowski MD FACEP received his medical degree from Jefferson medical College in 1982 and completed his residency in Emergency Medicine at Christiana Care from 1982 to 1985. Immediately upon graduation from residency, Dr. Nitowski joined Doctors for Emergency Service (DFES). He has served on the DFES Board of Directors and has been part of the DFES management team since 1989. He is a Past President of DFES having served from 1999 to 2016 in that capacity. 


Dr. Nitowski has wide experience in a variety of healthcare organizations, having previously served on the Board of Directors of a large hospital system, been Chairman of a large multispecialty physician organization, served on the Board of Directors of a health insurance company and medical billing company respectively along with a number of other varied roles related to healthcare organizations.


Dr. Nitowski also has been active in government affairs since the late 1990s up until recently. His leadership roles within DFES have previously involved day today management of all business affairs affecting DFES including human resources functions, medical legal affairs, and other aspects of running a medical practice such as revenue cycle management and contracting with third-party payers.


In his current and more limited role as Chairman of the Board of DFES, he provides governance oversight and supports the current President and other officers of DFES who run DFES operations on a day-to-day basis. 


He looks forward to celebrating 40 years in his professional life in Delaware this July 1, 2022.

Tom Sweeney, MD


Tom Sweeney graduated from the University of Rochester School of Medicine and completed his Emergency Medicine Residency at Carolinas Medical Center in Charlotte, North Carolina before joining DFES in 1993.  He had a long-standing interest in Emergency Medical Services and chaired the Emergency Management Committee (then the Disaster Committee of the Medical Center of Delaware), served as the first medical director of the Mobile Intensive Care Nurse Team, the first EMS medical director of the Delaware State Fire Prevention Commission, and then served as the New Castle County EMS Medical Director.  In 2001 he assumed the position of Associate Chair of the Department of Emergency Medicine, a role that he filled for 18 years.  In 2010 he earned a masters degree from Carnegie Mellon University in medical management.  He has served as a site reviewer for the American College of Surgeons Committee on Trauma and chairs the board of directors of Westside Family Healthcare, a federally qualified health center with over 200 employees.  He speaks fluent German and enjoys visiting family with his wife and three daughters in her homeland of South Tyrol, where only the hiking is better than the wine. Tom Sweeney was elected President of DFES in 2020.

Concrete Wall
Concrete Wall

John Powell, MD


A native downstate Delawarean, John Thomas Powell, MD, FACEP, attended Sussex Central High School.  He graduated from the University of Delaware and then worked with the Advisory Board Company before pursuing medical training at Jefferson Medical College.

Dr. Powell completed a surgical internship at Portsmouth Naval Medical Center in Portsmouth, VA.  He then attended the Naval Undersea Medical Institute in Groton, CT and the Navy Diving Salvage and Training Center in Panama City, FL where he studied radiation health, submarine and diving medicine.  He served active duty in the US Navy as a Diving Medical Officer with Submarine Squadron 22 in La Maddalena, Italy and later with Explosive Ordnance Disposal Group and Mobile Unit TWO in Little Creek, VA before entering residency.

Dr. Powell completed a residency in Emergency Medicine and a fellowship in Emergency and Point-of-Care Ultrasound at Christiana Care Health System in Newark, DE.  In 2014, he completed his Masters in Health Care Delivery Science through Dartmouth College. 

Dr. Powell married Jennifer Wilds in 2002, and the couple has two children.  He spends his free time with family or running, rucking, shooting and occasionally climbing.

Brent Passarello, MD


Dr. Brent Passarello was raised outside of Pittsburgh in the booming metropolis of Washington, Pennsylvania. He attended high school at Immaculate Conception and then completed his undergraduate education at Dickinson College. He graduated with an economics degree, worked for his family business for a year and then opted to pursue a medical degree. He completed a post-baccalaureate program at Bryn Mawr College and then matriculated at Thomas Jefferson University (aka The Sidney Kimmel Medical College – Thomas Jefferson University) and graduated in 1997. He did his residency at Christiana Care and became a full time member of DFES upon graduating. In his spare time he enjoys time with family, golf, and an occasional game of basketball and paddle tennis.

Concrete Wall
Concrete Wall

Leo Burns, MD


Dr. Burns is from a small town in Northeast Pennsylvania. He graduated from the University of Scranton and then attended Jefferson Medical College in Philadelphia, where he attained a medical degree. While doing a student rotation at the Medical Center of Delaware in Wilmington, Delaware, Dr. Burns became interested in emergency medicine. He trained as a resident in the Medical Center of Delaware emergency medicine residency program and then became an attending physician with DFES. The Medical Center of Delaware has since changed its name to Christiana Care.

Dr. Burns enjoys working for DFES at Christiana Care with an exceptional medical team dedicated to high quality and compassionate patient care. When not working in the emergency department, Dr. Burns likes to travel with his wife and two sons. They live in Glen Mills, PA.

Morganne Castiglione, MD

At-Large Member

Concrete Wall
Concrete Wall

Christian Coletti, MD

At-Large Member

A graduate of Haverford College in Haverford, PA., Christian Coletti, M.D. completed his medical training at Sidney Kimmel Medical College of Thomas Jefferson University in Philadelphia, PA.  Dr. Coletti completed a dual residency in Emergency/Internal Medicine and an administrative fellowship at Christiana Care Health System in Newark, De.  He also has a Masters in Health Care Delivery Science from Dartmouth.

Dr. Coletti joined Christiana Care in 2010 as a member of the Department of Emergency Medicine and the Department of Medicine. 

Dr. Coletti is a fellow of the American College of Emergency Medicine, the American Academy of Emergency Medicine, and the American College of Physicians.

Dr. Coletti has conducted extensive research, delivered presentations and lectures and authored and published papers in resuscitation and administrative topics. He has also contributed to patient education and community service programs.

Debra Ravert, MD

At-Large Member

Concrete Wall
Concrete Wall

Michael Schuh, PA-C

PA Representative

Operational Leadership

bottom of page