Developed By: Committee on Anesthesiologist Assistant Education and Practice
Original Approval: October 26, 2022
Certified Anesthesiologist Assistants (CAAs) are highly skilled professionals who work as a vital part of the anesthesia care team led by a physician anesthesiologist. They assist in the pre-operative anesthetic planning and intraoperative anesthesia care for patients having routine and complex procedures.
CAAs help balance and supplement the perioperative workforce and actively contribute to increased quality, decreased costs, and improved service line expansion efforts in patient care.
In the mid-1960s with the increased number and complexity of surgical procedures, there developed a widespread workforce shortage of anesthesia providers throughout the country. In response to this shortage, three anesthesiologists, Drs. Gravenstein, Steinhaus, and Volpitto, created the concept of the Anesthesiologist Assistant. These academic department chairs analyzed the spectrum of tasks required during anesthesia care and individually evaluated them based on the level of professional responsibility, required education and necessary technical skill. The result of this workforce analysis defined a new non-physician anesthesia provider linked to a supervising anesthesiologist, and the Anesthesiologist Assistant (AA) within the Anesthesia Care Team model was created.
This new anesthetist would function in the same role as the nurse anesthetist in the anesthesia care team led by a physician anesthesiologist. An innovative educational paradigm for anesthetists was created that built on a pre-medical background during college and led to a master’s degree that allowed for both vertical mobility toward a medical degree and lateral mobility into other areas requiring training in biomedical equipment and physiology, should the student wish to pursue other career possibilities in the future. The AA would remain under the supervision of the anesthesiologist within the anesthesia care team, which would allow for expansion of the anesthesiologist coinciding oversight of up to four patients.
The chairmen’s vision became a reality in 1969 when the first AA training programs began accepting students at Emory University in Atlanta, Georgia, and at Case Western Reserve University (CWRU) in Cleveland, Ohio. The first Emory class graduated with a Master of Anesthesiology Technology (MAT). In addition to didactic and practical material specific to anesthesia, both programs contained advanced coursework in physiology and pharmacology. These trainees were considered to be “applied physiologists.” The Emory program made premedical requirements a prerequisite for admission and the CWRU program incorporated these requirements into their bachelor’s degree program. Today, all programs are required to train CAAs at the master’s degree level and must be affiliated with a school of medicine. Every program has a physician anesthesiologist involved as the medical director.
- In 1989, the National Commission for Certification of Anesthesiologist Assistants was formed to establish a national certification process. As of June 2022, there are currently 17 accredited AA training programs located throughout the United States that graduate over 300 CAAs every year. This new type of anesthetist, whose clinical and technological skills complement the traditional medical role of the anesthesiologist, has advanced the quality and efficiency of care delivered by the anesthesia care team. (“History of the Profession | Emory School of Medicine”)
Since its inception, the anesthesiologist assistant profession has grown but remains a largely regionalized profession. Georgia was at the forefront of CAA practice (with CAAs gaining licensure in 1971) with Ohio not far behind. Currently, Anesthesiologist Assistants can practice in 21 states, federal districts, and/or U.S. territories either by licensure or delegatory authority.
Certified Anesthesiologist Assistant (CAA) Description of Profession and Clinical Practice:
Certified Anesthesiologist Assistants (CAAs) are highly skilled health professionals who work on the anesthesia care team led by a licensed physician anesthesiologists to implement anesthesia care plans. CAAs work exclusively within the anesthesia care team (ACT) 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, graduating with a master’s degree. 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 health care practitioners who aspire to practice in the anesthesia care team. Specifically, CAAs train and work under the supervision of physician anesthesiologists who retain responsibility for the immediate care of the patient. The care team model expands the medical treatment provided by the physician anesthesiologist and equips the medical facility to serve patients more efficiently, with the safest quality care. The CAA is competent to gather patient data, perform patient evaluation, and to provide and document the perioperative care for the patient that has been formulated with the anesthesiologist.
The tasks performed by CAAs reflect regional variations in anesthesia practice and state regulatory factors. CAAs work to deliver high-quality and comprehensive anesthesia care in the ACT led by a physician anesthesiologist, in agreement with the ASA Statement on the Anesthesia Care Team (ACT) and in accordance with the AAAA Statement on the ACT, the CAA’s functions include, but are not limited to, the following:
- Obtain an appropriate and accurate preanesthetic health history, perform an appropriate physical examination, and record pertinent data in an organized and legible manner
- Obtain diagnostic laboratory and related studies as appropriate, such as drawing arterial and venous blood samples and any other necessary patient fluids
- Insert and interpret data from invasive monitoring modalities such as arterial lines, pulmonary artery catheterization, and central venous lines, as delegated by the supervising physician anesthesiologist
- Administer anesthetic agents and controlled substances under the delegation of a supervising physician anesthesiologist. This includes, but is not limited to, administration of induction agents, maintaining and altering anesthesia levels, administering adjunctive treatment, and providing continuity of anesthetic care into and during the post-operative recovery period
- Airway management to establish and maintain a safe and appropriate airway and provide appropriate ventilatory support
- Apply and interpret advanced monitoring techniques
- Perform post-operative patient rounds by recording patient progress notes, compiling, and recording case summaries and by transcribing standing and specific orders placed by the physician anesthesiologist
- Evaluate and treat life-threatening situations and administer care, such as cardiopulmonary resuscitation, on the basis of established protocols (BLS, ACLS, and PALS)
- Perform duties in intensive care units, pain clinics, and other settings, as appropriate, under the supervision and delegation of an anesthesiologist
- Train and supervise personnel in the calibration, troubleshooting, and use of patient monitors
- Perform administrative duties in an anesthesiology practice or anesthesiology department, including management of personnel
- Participate in the clinical instruction of others
- Perform and monitor regional anesthesia to include, but not limited to, spinal, epidural, peripheral, and IV regional, and other special techniques such as local infiltration and nerve blocks under the delegation of an anesthesiologist
Pre-AA School Requirements:
Admission requirements for anesthesiologist assistant programs vary slightly among institutions. Overall, the requirements include a baccalaureate degree and completion of all of the premedical coursework required for admission to an American medical school.
Minor differences do exist between programs, but generalized admission requirements for students applying to an AA program include:
- Bachelor’s degree from an accredited institution
- Two semesters of biology with laboratory
- Two semesters of vertebrate anatomy and physiology (or other advanced biology) with laboratory
- Two semesters of general chemistry, one semester of organic chemistry, and either a second semester of organic chemistry or biochemistry, all with laboratory
- Two semesters of general physics with laboratory
- Two semesters of college mathematics including calculus
- Either the Medical College Admissions Test (MCAT) or the Graduate Records Admission Test (GRE)
- Prior health care experience is desired but not required
AA School Education:
The Commission on Accreditation of Allied Health Education Programs (CAAHEP) accredits AA training programs. CAAHEP focus is on quality outcomes, assuring that educational programs are preparing competent entry-level health care professionals. CAAHEP, the largest accrediting organization in the health sciences field, reviews and accredits more than 2200 entry level education programs in 32 health science professions. The American Society of Anesthesiologists is a CAAHEP member and participates in the accreditation processes for three health professions— anesthesiologist assistant, respiratory therapy, and emergency medical technician‐paramedics.
The minimum expectation as set out by the Commission on Accreditation of Allied Health Education Programs (CAAHEP) of an Anesthesiologist Assistant educational program is that they "prepare competent entry level anesthesiologist assistants in the cognitive (knowledge), psychomotor (skills), and affective (behavior) learning domains."
The curriculum for AA training is guided by general content areas that curriculum must cover and key words in specific content areas. General content areas covered must include topics such as: patient monitoring, medical biophysics, basic medical sciences (anatomy, physiology, etc.), interpretation of lab data, critical assessment of medical literature, patient assessment skills, quality assurance topics, and emergency preparedness.
Clinical requirement minimums for patient population specific cases, specific surgery types, methods of anesthesia, airway management techniques, and procedures are set by the program and guided by recommendations set by the CAAHEP. The minimum total number of anesthesia hours achieved during training is set at 2000 hours, or 600 cases, and this minimum must be met for a student to graduate. AA programs set internal hourly requirements for first year students. They also set a minimum number of cases by patient population and subspecialty for second and third year students.
Students must pass a national certifying exam for anesthesiologist assistants in order to become certified as an anesthesiologist assistant. They also must re-test every 10 years and maintain their national certification by submitting 40 continuing medical education credits (CMEs) every 2 years. The test is administered by the National Commission for Certification of Anesthesiologist Assistants (NCCAA). The NCCAA is an organization committed to assuring the public that certified anesthesiologist assistants (CAAs) meet the basic knowledge standards necessary to practice as a CAA.
Student AAs are not qualiﬁed clinicians. Students should provide anesthesia care ONLY in the presence of a physician anesthesiologist, physician fellow or anesthesia resident, CAA, or CRNA, while participating in the provision of anesthesia. The use of students in place of qualiﬁed anesthesia providers is inappropriate as well as inconsistent with the ASA Guidelines for the Ethical Practice of Anesthesiology.
Certification of CAAs:
Anesthesiologist assistants require formal certification to practice and deliver anesthesia for patients, in essence to become CAAs. The organization that designates certification is the National Commission for Certification of Anesthesiologist Assistants (NCCAA). This organization is analogous to the American Board of Anesthesiology (ABA), which certifies physician anesthesiologists. A major difference between the certification of CAAs and physicians is that physicians can practice without certification, CAAs cannot. Therefore, AAs must be certified at or shortly after graduation from an accredited training program. The program must be accredited by Accreditation Review Committee for the Anesthesiologist Assistant (ARC-AA) which serves under the auspices the Commission on Accreditation of Allied Health Education Programs (CAAHEP). The AA student can apply for and complete the initial certification examination prior to graduation. They must meet all the qualifications set by the NCCAA to sit for the examination which includes being in good standing with their training program with the expectation to graduate successfully within 6 months from the time of the examination. Certification is time limited and can be renewed, therefore a recertification process is available by the NCCAA. The CAA must demonstrate acceptable ethical standing in the profession, provide proof of continuing medical education (40 CME units per 2-year period) and pass the Continued Demonstration of Qualification (CDQ) examination every 10 years after their initial certification examination.
State Regulation: State Licensure vs. Delegated Authority:
The legal ability for CAA practice is created by legislation that is enacted and codified into state law or through regulation that is adopted by the board of medicine.
Certified Anesthesiology Assistants (CAAs) can practice within the Anesthesia Care Team (ACT) under two models: licensure authority or delegatory authority. Both state licensure and delegatory authority require oversight by a State Medical Board. Both delegatory authority and licensure can vary by state depending upon how the statute, rule or legislation reads. Currently CAAs may practice in nineteen states, Washington, D.C., and the U.S. territory Guam.
Approximately forty anesthesiologist assistants have also been trained as physician assistants (PAs) and are classified as PA/AAs, however, a PA may only practice as a CAA if he/she has completed an accredited AA program and passed the National Commission for the Certification of Anesthesiologist Assistants (NCCAA) exam. PA/AAs may only perform the duties of an anesthetist under the supervision of a physician anesthesiologist.
Although PAs have explicit statutory and/or regulatory authorization to practice in every state, PA/AAs have explicit statutory and/or regulatory authority to practice in only two states which do not have CAA licensure or delegatory authority. PA/AAs practicing in these two states, have successfully completed a PA program and passed the NCCPA examination.
Certain common law principles inherent to a physician’s authority and licensure may be delegated to an unlicensed person if there is a statutory grant of authority to delegate medical acts to unlicensed persons, and there is NOT a statement in the medical practice acts which precludes unlicensed persons from performing any “medical act,” a prohibition on unlicensed persons performing an injection, or a prohibition on unlicensed persons administering anesthesia.
Both delegatory authority and licensure implement CAAs within the ACT and require supervision by a physician anesthesiologist. Supervision ratio is dependent on the state. Some state licensure statutes set a ratio while others do not and defer to either the medical board to establish a ratio in the rules and regulations or rules established for billing and payment purposes.
State licensure for CAAs is created by legislation that is enacted and codified into state law or through regulation adopted by the board of medicine. With licensure, the CAA scope of practice is specified in regulation or statute. The rules of statutory interpretation are varied and may be subject to sunrise and commission reviews. Achievement of licensure can be a slow and expensive process.
Delegatory authority may occur through the state board of medicine recognition and action or in a state’s medical practice act enabling statute. In various medical specialties, including anesthesiology, the board of medicine may grant a physician the authority to delegate tasks or duties related to the practice of medicine to qualified individuals so long as the physician remains ultimately responsible to the patient and assures that the individual delegated to perform the tasks is qualified to do so. Delegatory authority presents a unique issue in terms of stability as reinterpretation of the provisions allowing for utilization of CAAs could risk termination. Hospital organizations which hire CAAs in states with CAA delegatory authority require bylaws that allow CAA delegated privileges.
Currently, anesthesiologist assistants can practice in 21 states, federal districts, and/or U.S. territories either by licensure or delegatory authority: CAA Practice Jurisdictions (through May 2022):
- Georgia – 1971, licensure
- Ohio – 1973, delegation; 2000, licensure
- Michigan – 1978, delegatory authority
- Wisconsin – 1980 delegatory authority, 2012, licensure
- Alabama – 1998, licensure
- Texas – 1999, delegatory authority
- New Mexico – 2001-2015, licensure (university hospitals only), 2015, licensure expanded to include Class A counties
- South Carolina – 2001, licensure
- Kentucky – 2002, licensure
- Missouri – 2003, licensure
- Vermont – 2003, licensure
- District of Columbia – 2004, licensure
- Florida – 2004, licensure
- North Carolina – 2007, licensure
- Oklahoma – 2008, licensure
- Colorado – 2012, licensure
- Guam – 2015, delegatory authority
- Indiana – 2015, licensure
- Kansas – 2021, delegatory authority
- Utah – 2022, licensure
- Pennsylvania – 2022, delegatory authority
Hospital and Facility Credentialing and Privileges:
Incorporating CAAs into an anesthesia care team will require consultation and engagement with organization/hospital legal counsel, medical board, credentialing and bylaws committees, insurance contracted companies or agencies, billing services, and accountants.
Credentialing can occur only after the facility’s bylaws recognize a CAA as an approved health care practitioner. The process of incorporating CAAs into a hospital organization or facility is near identical to that of incorporating PAs (Physician Assistants/Associates). For example, if the bylaws state that “PAs must be NCCPA‐certified,” change the language to state that “CAAs must be certified by the National Commission for Certification of Anesthesiologist Assistants (NCCAA).” CAAs work under the authority of an anesthesiologist’s license, and they often simultaneously practice with multiple physician anesthesiologists in a group.
There must be review and necessary adjustments and updates to include this new advanced practice provider in the medical staff bylaws, hospital rules and regulations, hospital or facility credentialing requirements, delineation of privilege forms, and organization policies and contracts which involve anesthesia services. It is important to include hospital administrators and medical staff leadership in new staff credentialling, as they can be instrumental in navigating through this process. Any review of governing allied health practitioners, to ensure that the newly proposed amendments do not conflict with any current facility bylaws.
CAAs must be a recognized health care provider within the hospital’s/facility’s bylaws. Proper modifications must be incorporated into the medical staff bylaws to allow for CAA scope of practice. In practices which currently utilize nurse anesthetists, a simple replacement of the term “CRNA” with “anesthetist” everywhere it occurs in your medical staff bylaws or policies handbook may suffice.
If the anesthesia practice is in a state with CAA licensure, these bylaws and policy changes should not be a problem. If in a state where CAAs have delegatory authority (DA), one should consult the component society of anesthesiologists, and the American Academy of Anesthesiologist Assistants (AAAA), as they may have already done a thorough legal analysis of your state’s medical practice act to ensure that DA is permitted. If this has not been done, it most likely will need to be. Your hospital may also wish to get a separate legal opinion. Explain to organizational stakeholders that DA is a widely used extension that allows for delegation of medical acts to a qualified practitioner with the anesthesiologist retaining authority and responsibility for the care being delegated. If there are no nurse anesthetists within the facility, the scope of practice should at least follow the scope of CAA training and not conflict with any existing CAA statutes or rules and regulations. The hospital/facility’s scope of practice may be more limiting than the state law, but the state supersedes that of the hospital/facility. There must be assurance that the facility’s bylaws and credentialing for CAAs as well as the anesthesia department’s policies and procedures do not conflict with the CAA statutes or medical board’s rules and regulations of CAA practice within the state.
All department of anesthesiology policies and procedures must be changed/amended to include CAA practice as well. Any reference to a CRNA or nurse anesthetist must be changed to either also include CAA with the same privileges, or change all references of CRNA to anesthetist, and then define anesthetist as either a CRNA or a CAA. All appropriate department documentation (department’s anesthesia record, anesthesia orders, and any documents which may have legal significance) should be changed to include CAAs.
It is important to educate surgical colleagues, chief of staff, and hospital administrators preemptively on CAA scope of practice, and how they can positively impact the organization by enhancing and extending the physician-led anesthesia care in your facility. Let them know that CAAs have an identical scope of practice to CRNAs in the ACT, and most hospitals and outpatient centers utilize both types of anesthesia advance practice providers interchangeably. Explain physician anesthesiologists remain immediately availability which is necessary in the demanding and complex environment of the operating room where medical emergencies can quickly arise. Before utilizing CAAs in your practice, it is advisable to educate and prepare the nurses and other staff in your operating rooms for the arrival of these new practitioners.
Department leadership and faculty must decide what the CAA scope of practice will be within their institution, and it should align with the CRNA scope of practice in the ACT. Decisions of the types of surgical cases or specific procedures that CAAs will and will not perform should be clearly delineated (i.e.: assistance in obstetrical or cardiac cases, placement of arterial or central lines or performance of regional blocks, etc., must be predetermined). Determine what the CAA call coverage will be. All of this should be spelled out in the credentials requested. It is important to preemptively establish department policy and rules for CAA practice, so the hospital, surgeons, and operating room staff will understand what their practice expectations will be. In addition, CAA applicants should be told in advance of hire what the position will entail.
An excellent resource to help one understand how to incorporate CAAs into practice is an anesthesia practice that has already incorporated, and currently utilizes CAAs. Initiate discussion with groups who have done so, followed by observance of their practice when possible. Colleagues who work with CAAs on a regular basis will have valuable insights into the hospital / facility credentialling process.
Department executives and administrators will need to establish salary and benefits. There will likely need to be adjustments to the reimbursement model, insurance arrangements, employment contracts, benefit packages and scheduling logistical updates. For departments utilizing CRNAs, salaries for CAAs should be equivalent.
Billing, Coding, Reimbursement, and Compliance:
Medicare coverage, billing, and payment for non-physician certified anesthesiologist assistant (CAA) anesthetists requires the following:
- Work under the supervision of an anesthesiologist who is immediately available and supervises when anesthesia is administered in a hospital, CAH or ASC.
- Comply with all applicable state law requirements, including any state licensure requirements imposed on non-physician anesthetists.
- Have graduated from a medical school-based AA education program that is accredited by the Commission on Accreditation of Allied Health Education Programs and includes approximately 2 years of specialized science and clinical education in anesthesia at a level that builds on a premedical undergraduate science background.
- Are authorized and qualified to furnish the services in the state where performed.
- Services are not otherwise precluded due to a statutory exclusion, and the services are reasonable and necessary.
The following Medicare billing guidelines apply:
- CAAs may bill the Medicare program either directly for services using their NPI, or under the NPI of a hospital, physician, group practice, or ASC where they have an employment or contractual relationship.
- Anesthesia time billed is the continuous period that begins when the anesthesia practitioner begins to prepare the patient for anesthesia services in the operating room or an equivalent area and ends when the anesthesia practitioner is no longer furnishing anesthesia services to the patient.
Anesthesia billing modifiers include:
- QS – Monitored anesthesia care service NOTE: A physician or a qualified non-physician anesthetist can use the QS modifier for informational purposes. Providers must report actual anesthesia time and one of the payment modifiers on the claim.
- QK – Medical direction of two, three or four concurrent anesthesia procedures by an anesthesiologist
- QY – Medical direction of one qualified nonphysician anesthetist service with medical direction by a physician
- QX – Qualified nonphysician anesthetist with medical direction by a physician
Medicare makes payment only on assignment and predicates payment to Part B copayments, deductibles and/or coinsurance. Services are paid under the Anesthesia Fee Schedule based on the applicable locality adjusted anesthesia conversion factor (CF) multiplied by the sum of allowable base and time units; one anesthesia time unit typically equals 15 minutes of anesthesia time.
Review the most current edition of the Medicare Claims Processing Manual and related state-level guidance documents to ensure alignment with current billing requirements.
CAAs are recognized by the Centers of Medicare and Medicaid (CMS), Tri-care, and all major commercial insurance payors. CMS recognizes CAAs as qualified non-physician anesthesia providers, just like their nurse anesthetist (CRNA) counterparts.
Statement Comparing CAAs to CRNAs:
The anesthesia care team (ACT) is led by a physician anesthesiologist who provides supervision to a Certified Anesthesiologist Assistant (CAA), a Certified Registered Nurse Anesthetist (CRNA) or an anesthesiology resident or fellow.
Refer to the ASA Statement Comparing Anesthesiologist Assistant and Nurse Anesthetist Education and Practice and the ASA Statement on the Anesthesia Care Team.
In the operating room, anesthesiologist assistants and nurse anesthetists perform the same role. They are interchangeable for both routine and complex surgical procedures and for breaks and end of day relief. Both serve as clinical advanced practice providers in the delivery of anesthesia. Identical medical staff privileging descriptions are appropriate for both categories of anesthesia professionals.
There is no peer-reviewed or other credible evidence of any sort that the care provided by a CAA is less safe than that of a CRNA within the anesthesia care team. In fact, in a study published in the October 2018 edition of Anesthesiology, after evaluating evidence regarding the anesthesia care team composition and surgical outcomes, Sun et al stated, “In conclusion, among elderly patients undergoing inpatient surgery, our study found no significant differences in outcomes between care teams with anesthesiologist assistants compared to care teams with nurse anesthetists.” They found that the specific composition of the anesthesia care team, whether made up of a physician anesthesiologist with a CAA or a physician anesthesiologist with a CRNA, was not associated with any significant differences in mortality, length of stay, or inpatient spending. Statistics and studies have proven time and time again that patients receive the most comprehensive and highest quality of perioperative care when provided by an anesthesia care team.
The anesthesiologist assistant profession, established in 1968, has been serving patients for over four decades. CAAs are recognized by the Centers of Medicare and Medicaid Services (CMS), Tri-care, and all major commercial insurance payers. CMS recognizes CAAs as qualified non-physician anesthesia providers, just like their CRNA counterparts. CAAs are as safe and competent as CRNAs.
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Integrating Anesthesiologist Assistants into your Practice: What you need to know. Mesrobian J, Stephenson J, Biel D, Nichols M, https://www.asahq.org/-/media/sites/asahq/files/public/resources/practice-management/ttppm/integrating-anesthesiologist-assistants-into-your-practice.pdf
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Bryce Amburgey. Miriam Fordham. Ben Payne. Matt Trebelhorn. Research Report No. 337. Legislative Research Commission. Frankfort, Kentucky. lrc.ky.gov, February 2007
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