ASA physical status assignment by non-anesthesia providers: Do surgeons consistently downgrade the ASA score preoperatively?

Abstract

Objective: The American Society of Anesthesiologists physical status (ASA-PS) is associated with increased morbidity and mortality in the perioperative period. When surgeries are scheduled by surgeons and their staff at our large institution a presumed ASA-PS is chosen. This is because our institution (and, anecdotally, others in our hospital system and elsewhere), recognizing the relationship between higher ASA-PS and poorer postoperative outcomes, requires all patients with higher ASA-PS levels (≥3) to undergo enhanced preoperative workup. The patients may not, however, necessarily be seen in the anesthesia clinic prior to surgery. As a result, patients are assigned a presumed ASA-PS by a non-anesthesia provider (e.g., surgeons and physician extenders) that may not reflect the ASA-PS chosen by the anesthesiologist on the day of surgery. Errors in the accuracy of the ASA-PS prior to surgery lead to unnecessary and costly preoperative testing, delays in operative procedures, and potential case cancellations. Our study aimed to determine whether there are significant differences in the assignment of ASA-PS by non-anesthesia providers when compared to anesthesia providers.

Design: We administered an IRB-approved survey asking the ASA-PS of 20 hypothetical case vignettes to 229 clinicians in various departments. Responses by non-anesthesia providers were compared to the consensus of the department of anesthesiology.

Setting: Faculty office spaces and conferences.

Patients: No patients, physicians only.

Interventions: Survey administration.

Measurements: ASA-PS scores acquired from surveys.

Main results: Residents and faculty in the department of anesthesiology demonstrated no statistical difference in the median ASA score in 19/20 case scenarios. All other departments were statistically different when compared to the department of anesthesiology (p<0.05). The probability of a department either over- or under-rating the ASA-PS was calculated, and is summarized in Fig. 3. All departments, except anesthesiology, had a 30-40% chance of under-rating the ASA-PS of the patients in the clinical vignettes.

Conclusions: Non-anesthesia providers assign ASA-PS with significantly less accuracy than do anesthesia providers, even when adjusted for multiple comparisons. Surgical and procedural departments were found to consistently under-rate the ASA-PS of patients in our clinical vignettes.

Keywords: ASA classification; ASA score; ASA-PS.