Which ASA class describes severe systemic disease that is a constant threat to life?

• A. ASA 3
• B. ASA 4
• C. ASA 5
• D. ASA 6

Answer: (B)

Understanding the ASA physical status system helps you gauge perioperative risk based on systemic disease. Describing a severe systemic disease that is a constant threat to life matches ASA IV. This means the patient’s condition is so serious that their life is at ongoing risk even without anesthesia, requiring careful planning, possible preoperative stabilization, and heightened intraoperative vigilance. It’s different from ASA III, where the disease is severe and limits activity but isn’t an immediate, constant threat to life, and from ASA V, where the patient is moribund and unlikely to survive without the operation, or ASA VI, which refers to brain-dead patients.