Pro: The ASA Physical Status Classification System is Invaluable

Educational Objectives

The goal of this program is to improve perioperative use of the American Society of Anesthesiologists (ASA) physical status classification system. After hearing and assimilating this program, the clinician will be better able to:

1. Recognize correlations between ASA physical status classification and other perioperative risk indexes.

2. Elaborate on the advantages of the ASA physical status scoring system for perioperative patient assessment.

Summary

Development of American Society of Anesthesiologists (ASA) Physical Status Classification scoring: originally developed in 1940s; purpose to classify patients according to their illnesses; developed by consensus among small number of committee members without specific data; recently upgraded, again by consensus among small number of committee members without specific data; upgraded system includes examples; upgrade did not necessarily improve ASA classification; includes vague, poorly quantified terms (eg, “healthy,” “social” vs “minimal” alcohol use); ASA II represents mild disease; ASA III represents severe disease; no intermediate classification for moderate disease

Purpose of ASA physical status classification: originally developed to quantify preoperative health status of patients; validity for this purpose demonstrated by many studies; usefulness as predictor of risk debatable; speaker believes ASA classification does evaluate anesthetic risk, does predict surgical outcomes or risks, and correlates well with operating room (OR) times; higher ASA physical status classification correlates with longer operative times for same procedure; ASA classification predicts transfusions and has moderate ability to predict cardiac complications; closely related to variety of postoperative complications, including infection rates, duration of mechanical ventilation postoperatively, and postoperative delirium; aligns well with duration of stay in intensive care unit; shown to predict overall morbidity; correlates well with low- and high-risk surgeries across wide range of procedures

Correlation with other risk indexes: predictive value of age alone debatable; speaker states age independently predicts risk; ASA physical status tracks well with patient age; ASA physical status correlates well with Charlson Comorbidity Index, Revised Cardiac Risk Index, and assessments of frailty; assessments correlate with length of hospital stay and postoperative risk; ASA physical status shown to predict risk ≤1 yr postoperatively; strong interdependence between ASA physical status and American College of Surgeons National Surgical Quality Improvement Program (NSQIP) clinical risk factors and NSQIP scoring system; ASA physical status shown to predict in-hospital mortality and rates of mortality after discharge

Inclusion in risk calculation systems: ASA physical status among factors included in American College of Surgeons NSQIP Surgical Risk Calculator and Gupta Perioperative Risk for Myocardial Infarction or Cardiac Arrest (MICA) calculator; Revised Cardiac Risk Index (RCRI) does not include ASA status; increasing ASA classification correlated with increased risk for pulmonary complications on several pulmonary scoring systems

Variation in assigning ASA physical status: study showed ASA scores assigned by anesthesiologists in OR frequently 1 or 2 points higher than scores assigned in preoperative clinic for same patient; speaker suggests surgical procedure has greater influence on anesthesiologist in OR than in preoperative clinic; variation in scoring among biggest criticisms of ASA physical status; many studies investigating variation used hypothetical patients; study participants provided list of medical conditions; often lacked details, including proposed surgery; another study showed significant variation between anesthesiologists working in private practice and those in university hospitals; speaker suggests possible influence of higher reimbursement from Centers for Medicare and Medicaid Services for patients classified as ASA III or ASA IV; non-anesthesiologists appear to have greater difficulty with ASA physical status classification; studies show larger variation between non-anesthesiologists and anesthesiologists than between anesthesiologists

Reliability with real patients: Sankar et al (2014) retrospectively analyzed data from real OR cases; two-thirds of patients assigned same ASA classification by preoperative clinic and operative personnel; ≈99% differed by ≤1 ASA classification; differences most commonly occurred between ASA classes II and III; speaker suggests opportunity to interview and interact with real patients improves reliability of ASA scoring among raters

Role of experience: most anesthesia professionals apply past experiences when assigning ASA classification; studies show older, more experienced anesthesia professionals more likely than younger anesthesia professionals to assign higher ASA classification

Ideal scoring system: would incorporate high specificity, high accuracy, and reproducibility without becoming too cumbersome to use; most currently available accurate, reproducible, and specific indexes are cumbersome and difficult to use without leveraging technology; speaker suggests simpler, easier to use system preferable, even with some loss of specificity and accuracy

Sequential Organ Failure Assessment (SOFA) score: previously known as Sepsis-related Organ Failure Assessment score; updated score almost as accurate as original and includes fewer elements

Value of ASA physical status classification: strongest criticisms include too simple, very subjective, and nonspecific; can also view same factors as strengths; no diagnostic tests required; no need to know specific values or test results; easy to remember; calculation of score intuitive

Potential improvements to ASA physical status: include classification between II and III; consider addition of modifiers (eg, T for trauma, P for pregnancy or pediatric, C for cancer, F for frailty); use big data; leverage technology; develop calculator; pull data from electronic record, diagnostic codes, and list of medications; consider modifiers for different conditions, including obesity, pediatrics, pregnancy, age, airway compromise, functional capacity, and frailty; Visnjevac et al (2015) found functional independence predicted outcomes independently of ASA classification

Additional arguments in favor of ASA physical status classification: has uses other than patient classification (eg, risk assessment); used for consideration of quality of care, use of resources, and staffing of personnel; adopted by veterinarians; shown highly predictive in animals and nonhuman primates, particularly as predictor of risk

Readings

Sequential Organ Failure Assessment (SOFA) score calculator. https://www.thecalculator.co/health/Sequential-Organ-Failure-Assessment-(SOFA)-Score-Calculator-862.html. Accessed September 11, 2019; American Society of Anesthesiologists: ASA physical status classification system. https://www.asahq.org/standards-and-guidelines/asa-physical-status-classification-system. Accessed September 11, 2019; Knuf KM et al: Clinical agreement in the American Society of Anesthesiologists physical status classification. Perioper Med (Lond). 2018;7:14; Sankar A et al: Reliability of the American Society of Anesthesiologists physical status scale in clinical practice. Br J Anaesth. 2014 Sep;113(3):424-32; Visnjevac O et al: The effect of adding functional classification to ASA status for predicting 30-day mortality. Anesth Analg. 2015 Jul;121(1):110-6.

Disclosures

For this program, members of the faculty and planning committee reported nothing to disclose.

Acknowledgements

Dr. Sweitzer were recorded at the 72nd Postgraduate Assembly in Anesthesiology, held December 7-11, 2018, in New York, NY, and presented by the New York State Society of Anesthesiologists. For information about upcoming CME opportunities from the New York State Society of Anesthesiologists, please visit www.nyssa-pga.org. The Audio Digest Foundation thanks the speakers and the New York State Society of Anesthesiologists for their cooperation in the production of this program.

CME/CE INFO

Accreditation:

The Audio- Digest Foundation is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.

The Audio- Digest Foundation designates this enduring material for a maximum of 0 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Audio Digest Foundation is accredited as a provider of continuing nursing education by the American Nurses Credentialing Center's (ANCC's) Commission on Accreditation. Audio Digest Foundation designates this activity for 0 CE contact hours.

Lecture ID:

AN614301

Expiration:

This CME course qualifies for AMA PRA Category 1 Credits™ for 3 years from the date of publication.

Instructions:

To earn CME/CE credit for this course, you must complete all the following components in the order recommended: (1) Review introductory course content, including Educational Objectives and Faculty/Planner Disclosures; (2) Listen to the audio program and review accompanying learning materials; (3) Complete posttest (only after completing Step 2) and earn a passing score of at least 80%. Taking the course Pretest and completing the Evaluation Survey are strongly recommended (but not mandatory) components of completing this CME/CE course.

Estimated time to complete this CME/CE course:

Approximately 2x the length of the recorded lecture to account for time spent studying accompanying learning materials and completing tests.