Predictors of the need for critical care after total joint arthroplasty: an update of our institutional risk stratification model.

Based on our previously published risk stratification model, 295 (19%) of a consecutive series of 1594 TJA patients were triaged to the ICU. However, only 67 patients (22%) required intensive care interventions. We identified 5 independent multivariate predictors (P < 0.001) including COPD, CAD, CHF (1 point each), EBL > 1000 mL, and intraoperative vasopressors (2 points each) to form the Penn Arthroplasty Risk Score (PARS). Patients with a score of 0 through 7 had a probability of requiring critical care of 7.0%, 13.2%, 23.5%, 38.1%, 55.4%, 71.4%, 83.4%, and 91.1% respectively. Based on these results, our previous risk stratification protocol is overly sensitive and non-specific. Any risk stratification algorithm for ICU admission should include intraoperative risk factors in order to be fully predictive.