Analysis of the American Society of Anesthesiologists Physical Status Classification System and Caprini Risk Assessment Model in Predicting Venous Thromboembolic Outcomes in Plastic Surgery Patients

Abstract

Background Venous thromboembolism (VTE) can be a fatal outcome of plastic surgery. Risk assessment models attempt to determine a patient's risk, yet few studies have compared different models in plastic surgery patients. Objective The authors investigated preoperative ASA physical status and 2005 Caprini scores to determine which model was more predictive of VTE. Methods A retrospective chart review examined 1801 patients undergoing contouring and reconstructive procedures from January 2008 to January 2012. Patients were grouped into risk tiers for ASA scores (1-2 = low, 3+ = high) with 2 cutoffs for Caprini scores (1-4 = low, 5+ high; 1-5 = low, 6+ = high), then re-stratified into 3 tiers using Caprini score cutoffs (1-4 = low, 5-8 = high, 9+ = highest; 1-5 = low, 6-8 = high, 9+ = highest). Median scores of VTE patients were compared to those without VTE. Odds ratio and chi-squared analyses were performed. Results Of the 1598 patients included in the study, 1.50% developed VTE. Median ASA scores differed significantly between comparison groups but Caprini scores did not vary regardless of cutoff. When examining the 2-tiered Caprini scores, using low risk = 1-5 showed a significant relationship between risk tier and DVT development (P = 0.0266). Conclusion The ASA system yielded the highest odds ratio of VTE development between low and high-risk patients. The Caprini model captured more patients with VTE in its high-risk category. Combining the two models for a more heuristic approach to preoperative care may identify patients at higher risk. Level of Evidence 4 Risk .