In 1968 Dr. Ed Krigbaum was one of  the first anesthesiologist who worked at St. Joseph Mercy Hospital,  Krigbaum was then joined by Dr. George Chatas and these two together founded Anesthesia Associates of Ann Arbor.  Forty-seven years later St. Joseph Mercy Health System remains one of A4’s largest sites of service. Today, A4 is comprised of 95 board certified/eligible anesthesiologists with sub-specialty training/certification in pediatric, obstetrics, cardiac, regional anesthesia, critical care medicine, trans-esophageal echocardiography, and chronic pain management.

A4 provides physician anesthesia coverage for over 150,000 cases annually and performs over 11,000 pain management procedures per year. A4’s revenue is $45 million.At each facility, we have an anesthesiologist that is the appointed Medical Director of that site. A4 is committed to working with Hospital Administration to provide leadership at all levels. We are privileged to have 3 of our partners serve as Chief of Staff at three separate hospitals. A4 offers 5 different service lines including; Anesthesia, Perioperative Management, Critical Care, Pain Management, and Office-Based practice.