Utility of the Surgical Apgar Score in a district general hospital.

BACKGROUND

The Surgical Apgar Score (SAS) is a simple tool for intraoperative risk stratification. The aim of this prospective observational study was to assess its performance in predicting outcome after general/vascular and orthopedic surgery and its utility in a U.K. district general hospital.

METHOD

A prospective cohort of 223 consecutive general, vascular, and orthopedic surgical cases was studied. The SAS was calculated for all patients, and its relationship to 30 day mortality and major complication assessed with reference to the mode of surgery (elective or emergent). Statistical analysis of categorical data was performed with Fisher's exact test and the AUC (area under the curve) on receiver operating characteristic (ROC) analysis. Selected cases were reviewed to assess the potential of the SAS to modify postoperative management.

RESULTS

The proportion of patients who died or experienced major complications increased monotonically with Surgical Apgar Score category in general and vascular but not orthopedic cases. The relative risks of mortality or major complication between SAS categories were less marked than in previous publications. The SAS performed variably on ROC curve analysis, with an AUC of 0.62-0.73. Discrimination achieved significance in general and vascular cases (p = 0.0002) but not in orthopedic cases (p = 0.15). Subgroup analysis of high (SAS < 7) and low risk (SAS ≥ 7) groups demonstrated utility of the score in general surgery and vascular cases overall (p < 0.0001), and in the emergency (p = 0.004) but not elective (p = 0.12) subgroups. Case note review of those patients who died indicated that despite their identification by the SAS, there would have been limited scope to modify outcome.

CONCLUSION

This study provides further evidence that the SAS is a simple and effective predictive tool in the emergency general and vascular surgical setting. It appears to have a limited role in the management of individual patients after orthopedic surgery and elective general/vascular surgery. The SAS has been proven to reliably stratify risk in larger populations and might be applied most usefully as a marker of quality. Further studies are required to determine whether its application can influence outcome.