Which ASA classification corresponds to a patient with severe life-threatening systemic disorder?

The ASA classification system is used to assess the physical status of patients prior to anesthesia and surgery. A patient classified as ASA class 4 has a severe systemic disorder that poses a constant threat to life. This classification acknowledges that the patient's medical condition is significant and may lead to serious complications during the procedure, making it critical for healthcare providers to take extra precautions.

Patients in ASA class 2 are described as having mild systemic disease, which does not pose a significant risk. ASA class 3 patients have severe systemic disease, but these conditions are not immediately life-threatening. ASA class 5 refers to patients who are not expected to survive without surgical intervention; they are critically ill and face a threat to life.

Thus, ASA class 4 is specifically reserved for patients whose severe medical issues create an ongoing life-threatening scenario, justifying its designation as the correct classification for such patients in the context of anesthesia.