American Society of Anesthesiology Physical Status

Predicated on patient-specific risk factors, the American Society of Anesthesiology (ASA) Physical Status (PS) classification system provides a practical and validated method to determine perioperative risk for patients undergoing surgical (and by extension dental) procedures (Table 6).22,23 In general, surgical stress-related changes are well tolerated by normal healthy patients (ASA PS I) and those with well-controlled systemic disease (ASA PS II).

Table 6. Modified ASA Physical Status Classification.22,23
  1. Normal healthy patient – no limitation of physical activity
  2. Patient with mild systemic disease – no or minimal limitation on physical activity
  3. Patient with moderate to severe systemic disease – moderate to marked limitation on physical activity
  4. Patient with incapacitating systemic disease - no residual functional reserve
  5. Moribund patients not expected to survive 24 hours

In oral healthcare settings patients may experience life threatening endocrine/metabolic events such as hypoglycemia, severe hypoadrenocorticism, severe hypo- or hyperthyroidism; however, these MMEs are most likely patient-related and not procedure-related complications. The rate of major perioperative medical complications correlates closely to the ASA PS classification of patients and ranges from 0.4/1000 for ASA PS I to 9.6/1000 for ASA PS IV.24