About Us

Group doc in OR

About Anesthesia Management Services

At Anesthesia Management Services PC, we provide unmatched anesthesia care across the greater Detroit area. As a completely independent practice, we are 100% physician-owned and have no private equity or venture capitalist involvement, keeping control in our own hands to make the best decisions for our people, our patients and our business. Get to know us a little more below.



Our team is comprised of strong leaders with varying backgrounds and perspectives who work together to ensure the group’s success.  Click on our leaders' pictures to learn more about them.


Harpreet Singh, MD



Ali Sabbagh, MD, MBA



John Ghanem, MD



Joseph Gizoni, CRNA, MS

Director of Operations



Michael Duronio, CRNA, MS

Director of Ambulatory Operations


Jeremy Roberts, DO

Jeremy Roberts, DO

Chief Medical Officer
Chief Compliance Officer

Physicians, CRNAs, and Staff

Our team is made up of more than 60 on-staff Anesthesiologists and 150 CRNAs, as well as Anesthesia Techs and an efficient support staff. With a focus on work-life balance, flexible schedules, a fun culture and diverse values that are recognized, supported and celebrated, AMS is a welcoming group poised for continued growth and success.

Ambulatory Surgery Centers
Shelley Colar

Shelley Colar

Assistant Director of CRNA Services

“As a member of the AMS team, I am able to provide various forms of care at level-one trauma centers, ambulatory surgical centers and office-based anesthesia. I enjoy being part of the leadership team and modeling quality care in anesthesia as a vital part of my and the entire organization’s daily practice.”


Laura Weaver

Manager of Credentialing and Scheduling

“I’ve spent more than a decade as part of this team for many reasons. What I most love about working within the AMS team is the care for each other that everyone demonstrates and how they appreciate hard work and dedication.” 

Margaret Blevins

Margaret (Mag) Blevins

Lead Administrative Assistant

“For the past 22 years, I have worked with this fantastic group of anesthesia professionals and have learned that every day is different. I am beyond proud to be able to witness the excellent care they give to each and every one of our patients and I am very happy to call them my work family!”