To the Editor:—

In the article about variability in surgical procedure times published in the May issue of Anesthesiology, 1I was dismayed to find numerous (15) references to the American Society of Anesthesiologists (ASA) Physical Status Classification system as ”ASA risk class,”“ASA values,” and “ASA risk scores.” None of these characterizations of the Physical Status Classification system is appropriate. Drs. Meyer Saklad, 2Ivan Taylor, and E. A. Rovenstein originally designed the system as a categorization system for statistical studies. They recognized from the beginning that “operative risk” was not an item to be included in the classification system because it is altered by the nature of the surgical procedure. The American Society of Anesthesiologists House of Delegates has modified the system several times in the past 59 yr, but risk was not included in any modification.

Many studies have shown a correlation between mortality and physical status class, but these are only in a surgery-specific analysis. That does not make the system a risk stratification system. The ASA Physical Status system was, and is, a means to stratify a patient’s systemic illness. Certainly, a patient’s inherent protoplasm is a part of systemic illness and indirectly may lead to adverse occurrences. The kind of operative procedure is not a part of the classification system because a physical status III patient is still in that status if scheduled for an excision of a skin lesion with monitored anesthesia care or if scheduled for a pancreatectomy with general anesthesia. The operative risk is different because of the surgery, but the physical condition of the patient is the same preoperatively.

Strum DP, Sampson AR, May JH, Vargas LG: Surgeon and type of anesthesia predict variability in surgical procedure times. A nesthesiology 2000; 92: 1454–66
Saklad M: Grading of patients for surgical procedures. A nesthesiology 1941; 2: 281–4