A 70-year-old patient has chronic obstructive pulmonary disease that causes dyspnea on exertion but the patient remains ambulatory. Which ASA class applies?

• A. ASA II
• B. ASA III
• C. ASA IV
• D. ASA V

Answer: (B)

ASA physical status uses how a systemic disease affects a patient’s daily function to estimate perioperative risk. Mild systemic disease with no functional limitation is ASA II. When the systemic disease is more significant and causes clear functional limitation, but the patient is still able to walk and not bedbound, it falls into ASA III. Chronic obstructive pulmonary disease that produces dyspnea on exertion represents substantial systemic burden with reduced functional capacity, even though the patient remains ambulatory, so this scenario fits ASA III. ASA IV would require a constant threat to life from the disease, and ASA V describes a moribund patient not expected to survive without the operation.