ASA Provides Examples to Each ASA Physical Status Class

Amr E. Abouleish, M.D., M.B.A. is Professor, Department of Anesthesiology,University of Texas Medical Branch, Galveston.Marc L. Leib, M.D., J.D., is Chair, ASA Committee on Economics.Neal H. Cohen, M.D., M.P.H., M.S. is Professor of Anesthesia and Perioperative Care and Medicine, Vice Dean, University of California San Francisco School of Medicine.For more than 50 years, anesthesiologists have used the ASA Physical Status Classification System (ASA PS) to describe a patient’s preoperative and comorbid conditions. The original classification system proposed by Drs. Saklad, Rovensteine and Taylor in 1941 incorporated some examples of the clinical conditions for each physical status level to guide the assignment of a patient’s status.1 The system was subsequently modified by Dripps2 and adopted by ASA in 1962. Unlike the original system, this ASA classification system did not include any examples of each class. The system has become an integral part of the practice of anesthesiology and is used by anesthesiologists, surgeons and others to characterize patient populations in general and the preoperative medical conditions that might influence anesthetic management specifically. While there is some evidence to demonstrate uniformity in the assignment of the ASA PS level, a number of published studies have documented considerable lack of “inter-rater reliability.”3–9 Although there are concerns about reproducibility in the determination of ASA PS within the anesthesia community, the system has worked relatively well to categorize preoperative conditions for patients undergoing surgical procedures in an inpatient operating room environment. It has been used to assess “risk,” but was not intended to determine where or by whom anesthesia care would be provided. With advances in clinical management, new drugs and non-anesthesia providers delivering care, the use of the system has expanded far beyond its original intent. The ASA PS is no longer exclusively utilized by anesthesiologists to determine the patient’s preoperative condition, and, as importantly, the system is no longer “controlled” by ASA. The definitions and descriptors of the ASA PS are included in the CPT® code set, which is the property of the American Medical Association. For patients, this expansion in the use of the ASA PS has significant implications, since it is now being use to define where a patient can receive care, what care can be provided (e.g., moderate or deep sedation) and by what level of provider. The ASA PS is now being used for a variety of other purposes, including, but not limited to, those defined in Table 1.10–16Because of the expansion of the use of the ASA PS for purposes beyond its original intent, in October 2014, the ASA developed and approved some additional descriptors as examples to aid clinicians and others in the determination of the ASA PS17 (Table 2). At that time, ASA did not make any changes to the original definitions as used by the ASA, AMA and others. These examples were added to provide some context for the classic ASA PS definitions. They do not supplant the need for medical judgment in both determining the ASA PS and its implications about the patient’s condition and risk, the most appropriate site of care, the kind of service to be provided (moderate sedation, deep sedation, general anesthesia) or the specific training and skills of the provider.