American Society of Anesthesiologists Statement on ASA Physical Status Classification System

The American Society of Anesthesiologists (ASA) Physical Status Classification System has been in use continuously since 1961. The purpose of the system is to assess and communicate a patient’s pre-anesthesia medical comorbidities. The classification system in conjunction with other factors (e.g., type of surgery, frailty, level of deconditioning) helps anesthesiologists estimate perioperative risk. Patients with ASA Physical Status III or higher generally require more extensive pre-anesthesia evaluation and coordinated care along with more intense anesthesia care as compared with patients having ASA Physical Status I or II. 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. 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 - ASA PS Classification Definition Adult Examples, Including, but not Limited to: Pediatric Examples, Including but not Limited to: Obstetric Examples, Including but not Limited to: ASA I A normal healthy patient Healthy, non-smoking, no or minimal alcohol use Healthy (no acute or chronic disease), normal BMI percentile for age ASA II A patient with mild systemic disease Mild diseases only without substantive functional limitations or end organ involvement. Current smoker, social alcohol drinker, pregnancy, obesity (303 months) of MI, CVA, TIA, PE, or CAD/stents, significant cognitive dysfunction, isolated severe OSA regardless of CPAP compliance or any severity of obstructive sleep apnea with CPAP noncompliance. Poorly controlled DM or HTN with or without end organ dysfunction. Uncorrected stable congenital cardiac abnormality, asthma with exacerbation, poorly controlled epilepsy, insulin dependent diabetes mellitus, morbid obesity, malnutrition, severe OSA, oncologic state, renal failure, muscular dystrophy, cystic fibrosis, history of organ transplantation, brain/spinal cord malformation, symptomatic hydrocephalus, premature infant PCA <60 weeks, autism with severe limitations, metabolic disease, difficult airway, long term parenteral nutrition. Full term infants <6 weeks of age. Preeclampsia with or without severe features, gestational diabetes poorly controlled or with complications or high insulin requirements, a thrombophilic disease requiring anticoagulation. ASA IV A patient with severe systemic disease that is a constant threat to life Recent (<3 months) MI, CVA, TIA or CAD/stents, ongoing cardiac ischemia or severe valve dysfunction, severe reduction of ejection fraction or CHF NYHA class 4, shock, sepsis, DIC, ARDS, ESRD not undergoing regularly scheduled dialysis, uncompensated cirrhosis, severe cognitive dysfunction Symptomatic congenital cardiac abnormality, congestive heart failure, active sequelae of prematurity, acute hypoxic-ischemic encephalopathy, shock, sepsis, disseminated intravascular coagulation, automatic implantable cardioverter-defibrillator, ventilator dependence, endocrinopathy, severe trauma, severe respiratory distress, advanced oncologic state. Preeclampsia with severe features complicated by HELLP or other adverse event, peripartum cardiomyopathy, uncorrected/decompensated heart disease. ASA V A moribund patient who is not expected to survive without the operation Ruptured abdominal or thoracic aneurysm, massive trauma, intracranial bleed with mass effect, ischemic bowel in the face of significant cardiac pathology or multiple organ/system dysfunction Massive trauma, intracranial hemorrhage with mass effect, patient requiring ECMO, respiratory failure or arrest, malignant hypertension with hypertensive crisis, decompensated congestive heart failure, hepatic encephalopathy, ischemic bowel or multiple organ/system dysfunction. Uterine rupture, amniotic fluid embolism ASA VI A declared brain-dead patient whose organs are being removed for donor purposes *Although pregnancy is not a disease, the parturient’s physiologic state is significantly altered from when the woman is not pregnant, hence the assignment of ASA PS II for a woman with uncomplicated pregnancy.**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).ARDS, acute respiratory distress syndrome; ASA, American Society of Anesthesiologists; BMI, body mass index; CAD, coronary artery disease; CHF NYHA, congestive heart failure, New York Heart Association classification; COPD, chronic obstructive pulmonary disease; CPAP, continuous positive airway pressure; CVA, cerebrovascular accident; DIC, disseminated intravascular coagulation; DM, diabetes mellitus; ECMO, extracorporeal membrane oxygenation; ESRD, end-stage renal disease; HELLP, hemolysis, elevated liver enzymes, low platelets; HTN, hypertension; MI, myocardial infarction; OSA, obstructive sleep apnea; PCA, post-conceptual age; PE, pulmonary embolism; PS, physical status; TIA, transient ischemic attack