| Objectives. A 10-point Surgical Apgar Score, based on patients' estimated blood loss, lowest heart rate, and lowest mean arterial pressure during surgery, was recently developed to rate patients' outcomes in general and vascular surgery. In this study, we sought to evaluate its validity among hip and knee arthroplasty patients.;Methods. Using electronic intraoperative records, we calculated Surgical Apgar Scores for all patients who underwent hip and knee arthroplasty over a 42-month period in a single academic institution. We evaluated the relationship between scores and the likelihood of major postoperative in-hospital complications, and assessed its discrimination and calibration in arthroplasty.;Results. Of 3511 patients, there were 198 major complications (5.6%). Complication rates increased as the Surgical Apgar Score decreased, with complications found in 5.0% of patients with scores 7 or greater, compared to 26.1% of patients with scores 4 or less. Even after controlling for pre-operative risk characteristics, each 1 point decrease in the Surgical Apgar Score was associated with a 34.0% increase (95%CI 19-52%) in the odds of a complication. However, the overall discriminatory performance of the Score was a c-statistic of 0.61, and fully 75.8% of all major complications occurred in patients classified as relatively low risk with Scores of 7 or greater.;Conclusions. For hip and knee arthroplasty patients, the Surgical Apgar Score is insufficiently predictive to be relied on for comprehensive risk stratification. However, it does capture important intra-operative prognostic information regarding risk of complication and contributes additional information to pre-operative risk characteristics. |
