Certified Anesthesiologist Assistants (CAAs) are highly skilled health professionals who work under the direction of licensed anesthesiologists to implement anesthesia care plans. CAAs work exclusively within the anesthesia care team environment as described by the American Society of Anesthesiologists (ASA). All CAAs possess a premedical background, a baccalaureate degree, and also complete a comprehensive didactic and clinical program at the graduate school level. CAAs are trained extensively in the delivery and maintenance of quality anesthesia care as well as advanced patient monitoring techniques. The goal of CAA education is to guide the transformation of qualified student applicants into competent advanced practice providers (APPs) who aspire to practice in the anesthesia care team.

Certified Anesthesiologist Assistants and certified registered nurse anesthetists are both defined as "non-physician anesthetists" within the Centers for Medicare & Medicaid Services section of the Code of Federal Regulations.

In the 1960s, three anesthesiologists, Joachim S. Gravenstein, John E. Steinhaus, and Perry P. Volpitto, were concerned with the shortage of anesthesiologists in the country. These academic department chairs analyzed the spectrum of tasks required during anesthesia care. The tasks were individually evaluated based on the level of professional responsibility, required education and necessary technical skill. The result of this anesthesia workforce analysis was to introduce the concept of team care and to define a new advanced practice provider (APP) linked to a supervising anesthesiologist. This new professional - the Certified Anesthesiologist Assistant or CAA - had the potential to at least partially alleviate the shortage of anesthesiologists.

The new type of anesthetist would function in the same role as the nurse anesthetist under anesthesiologist direction. An innovative educational paradigm for anesthetists was created that built on a pre-med background during college and led to a Master's degree. This pathway placed CAAs on an anesthesia "career ladder". Some CAAs have leveraged their premed background, Master's degree and clinical experience to successfully apply to medical school. A few have returned to anesthesia to become the physician leader of the care team that launched their professional career.

The chairmen's vision became reality in 1969 when the first CAA training programs began accepting students at Emory University in Atlanta, Georgia, and at Case Western Reserve University in Cleveland, Ohio.

Although CAAs and physician assistants (PAs) both function as physician extenders, they do not perform the same functions. Each has its own separate educational curriculum, standards for accreditation, and its own agency for certification. PAs receive a generalist education and may practice in many different fields under the supervision of a physician who is qualified and credentialed in that field.

An AA may not practice outside of the field of anesthesia or apart from the supervision of an anesthesiologist. A CAA may not practice as a physician's assistant unless the CAA has also completed a PA training program and passed the National Commission for the Certification of Physician Assistants (NCCPA) exam.

Likewise a PA may not identify him- or herself as a CAA unless he or she has completed an accredited AA program and passed the National Commission for the Certification of Anesthesiologist Assistants (NCCAA) exam. If also certified as a CAA, such a dual-credentialed PA would be required to practice as an anesthetist only as an advanced practice provider (APP) for an anesthesiologist and could not provide anesthesia care at the direction of a physician of any other specialty.

Although both are considered to be equivalent clinical non-physician anesthesia providers and may serve as advanced practice provider (APP) in the delivery of anesthesia, CAAs and CRNAs are very different with regard to their educational background, training pathway and certification process.