ASA Physical Status Classification System
Developed By: ASA House of Delegates/Executive Committee
Last Amended: October 23, 2019 (original approval: October 15, 2014)
The ASA Physical Status Classification System has been in use for over 60 years. The purpose of the system is to assess and communicate a patient’s pre-anesthesia medical co-morbidities. The classification system alone does not predict the perioperative risks, but used with other factors (eg, type of surgery, frailty, level of deconditioning), it can be helpful in predicting perioperative risks.
The definitions and examples shown in the table below are guidelines for the clinician. To improve communication and assessments at a specific institution, anesthesiology departments may choose to develop institutional-specific examples to supplement the ASA-approved examples.
The examples in the table below address adult patients and are not necessarily applicable to pediatric or obstetric patients.
Assigning a Physical Status classification level is a clinical decision based on multiple factors. While the Physical Status classification may initially be determined at various times during the preoperative assessment of the patient, the final assignment of Physical Status classification is made on the day of anesthesia care by the anesthesiologist after evaluating the patient.
Current Definitions and ASA-Approved Examples
*The addition of “E” denotes Emergency surgery:
(An emergency is defined as existing when delay in treatment of the patient would lead to a significant
increase in the threat to life or body part)
|ASA PS Classification
||Adult Examples, Including, but not Limited to:
||A normal healthy patient
||Healthy, non-smoking, no or minimal alcohol
||A patient with mild systemic
||Mild diseases only without substantive
functional limitations. Examples include (but not
limited to): current smoker, social alcohol
drinker, pregnancy, obesity (30 < BMI < 40), well-controlled
DM/HTN, mild lung disease
||A patient with severe
||Substantive functional limitations;
One or more moderate to severe diseases.
Examples include (but not limited to): poorly
controlled DM or HTN, COPD, morbid obesity
(BMI ≥40), active hepatitis, alcohol dependence
or abuse, implanted pacemaker, moderate
reduction of ejection fraction, ESRD undergoing
regularly scheduled dialysis, premature infant
PCA < 60 weeks, history (>3 months) of MI,
CVA, TIA, or CAD/stents.
||A patient with severe
systemic disease that is a
constant threat to life
||Examples include (but not limited to): recent ( < 3
months) MI, CVA, TIA, or CAD/stents, ongoing
cardiac ischemia or severe valve dysfunction,
severe reduction of ejection fraction, sepsis, DIC,
ARD or ESRD not undergoing regularly
||A moribund patient who is
not expected to survive
without the operation
||Examples include (but not limited to): ruptured
abdominal/thoracic aneurysm, massive trauma,
intracranial bleed with mass effect, ischemic
bowel in the face of significant cardiac pathology
or multiple organ/system dysfunction
||A declared brain-dead
patient whose organs are
being removed for donor
For more information on the ASA Physical Status Classification system and the use of examples, the following publications are helpful. Additionally, in the reference section of each of the articles, one can find additional publications on this topic.
- Abouleish AE, Leib ML, Cohen NH. ASA provides examples to each ASA physical status class. ASA Monitor 2015; 79:38-9 http://monitor.pubs.asahq.org/article.aspx?articleid=2434536
- Hurwitz EE, Simon M, Vinta SR, et al. Adding examples to the ASA-Physical Status classification improves correct assignments to patients. Anesthesiology 2017; 126:614-22
- Mayhew D, Mendonca V, Murthy BVS. A review of ASA physical status – historical perspectives and modern developments. Anaesthesia 2019; 74:373-9