- Anesthesiologist Assistants Master of Science in Anesthesiology Program Case Western Reserve University Anesthesiologist Assistants (AAs) are allied health professionals who are recognized members of the Anesthesia Care Team. AAs, also referred to as anesthetists, work cooperatively under the direction of an anesthesiologist to implement the anesthesia care plan. AAs are trained in a ...www.anesthesiaprogram.com