# Predictive Value of the Surgical Apgar Score for Major Postoperative Complications: A Prospective Observational Study in a Tertiary Care Setting

## TL;DR

This study evaluated the Surgical Apgar Score's ability to predict postoperative complications in a mixed surgical group and found it to have limited usefulness as a standalone tool.

## Contribution

The study prospectively assessed the SAS in a heterogeneous surgical cohort and evaluated its discriminative performance with sensitivity analysis.

## Key findings

- 40.4% of patients experienced clinically relevant postoperative complications.
- The SAS showed limited to modest discriminative ability (AUC 0.623).
- The association between SAS and complications became significant when including ASA physical status.

## Abstract

Background: The Surgical Apgar Score (SAS) is a simple intraoperative scoring system proposed to estimate postoperative risk; however, its discriminative performance in heterogeneous surgical populations remains uncertain. This study prospectively evaluated the discriminative ability of the SAS for postoperative complications in a mixed surgical cohort.

Methods: In this prospective observational cohort study, adult patients (≥18 years) undergoing elective or emergency major surgical procedures, defined as operations performed under general or regional anesthesia with an anticipated postoperative hospital stay exceeding 48 hours, in general surgery and orthopaedics at a tertiary care center, were enrolled. Intraoperative variables were prospectively collected, and the SAS was calculated for each case. The primary outcome was the occurrence of clinically relevant postoperative complications within 30 days, excluding blood transfusion. Associations were assessed using multivariable logistic regression. Discrimination was evaluated using receiver operating characteristic (ROC) analysis, with prespecified sensitivity analysis including American Society of Anesthesiologists (ASA) physical status.

Results: A total of 95 patients were included (mean age 52.5 ± 18.7 years; 48.4% male). Clinically relevant postoperative complications occurred in 40.4% of patients. Lower SAS was associated with higher complication rates on unadjusted analysis. In the primary multivariable model adjusted for age, duration of surgery, and urgency of procedure, the SAS was not independently associated with the outcome. In sensitivity analysis including ASA physical status, the association between the Surgical Apgar Score and postoperative complications reached statistical significance (p = 0.035) and should be interpreted cautiously. ROC analysis demonstrated limited to modest discriminative ability (area under the curve (AUC) 0.623, 95% CI 0.517-0.728).

Conclusion: In this prospective heterogeneous surgical cohort, the SAS demonstrated limited to modest discriminative ability for clinically relevant postoperative complications. The findings suggest limited utility of the SAS as a standalone risk stratification tool in heterogeneous surgical populations. At most, the score may provide complementary intraoperative risk information when interpreted alongside established preoperative risk measures and clinical judgment. Further validation in larger, procedure-specific cohorts with standardized outcome definitions and internal validation is required.