Predictors of the Need for Critical Care After Total Joint Arthroplasty: An Update of Our Institutional Risk Stratification Model P. Maxwell Courtney, MD a , Colin M. Whitaker, BS a , Jacob T. Gutsche, MD b , Eric L. Hume, MD a , Gwo-Chin Lee, MD a a Department of Orthopaedic Surgery, University of Pennsylvania, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania b Department of Anesthesiology and Critical Care, University of Pennsylvania, Penn Presbyterian Medical Center, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania abstract article info Article history: Received 3 February 2014 Accepted 21 February 2014 Available online xxxx Keywords: total joint arthroplasty complications intensive care unit risk stratification 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 b 0.001) including COPD, CAD, CHF (1 point each), EBL N 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. © 2014 Elsevier Inc. All rights reserved. With the number of total joint arthroplasties projected to reach 4 million annually by 2030 [1], hospitals can be expected to allocate an increasing amount of critical care services to orthopaedic patients. Estimated hospital costs associated with total joint arthroplasty (TJA) reached $30 billion in 2004 and are expected to continue to increase. [1] Although TJA is widely regarded as a successful surgery with excellent patient outcomes, complications including pulmonary embolism, acute renal failure, tachyarrhythmia, and myocardial infarction can occur [2,3]. While one study supports improved outcomes when these patients are co-managed with internal medicine physicians [4], it is unclear which patients require a higher level of critical care monitoring. Determination of who should be triaged to the intensive care unit (ICU) postoperatively represents an important decision point with regard to patient safety and hospital resources. As advances in modern medicine have increased life expectancy, older patients with more medical comorbidities are undergoing total joint arthroplasties [5]. Studies have shown an increased complication rate after TJA in patients with diabetes, hypertension, obesity, and higher American Society of Anesthesiologists score [6–9]. Two studies have reported a rate of major adverse events such as pulmonary embolism, tachyarrhythmia, and myocardial infarction between 1.7% and 4.6% after TJA [2,10]. Although one study found that 58% of patient who experienced a serious medical complication after TJA had no predisposing risk factors [11], identifying at risk patients preoperatively can improve patient outcomes and decrease mortality. At our institution, Kamath and colleagues developed a model based on preoperative risk factors to stratify patients undergoing elective THA and demonstrated that this protocol significantly reduced mortality and unplanned admis- sions to the ICU [13,14]. However, while this initiative has improved patient safety at our institution, a significant number of patients were triaged to the ICU unnecessarily; increasing cost and straining hospital resources. This study aims to determine the “at risk” patient following arthroplasty in order to triage them appropriately to areas where a higher level of monitoring or interventions could be delivered. Therefore, the purpose of our study is to 1) evaluate the number of patients triaged to ICU actually requiring critical care interventions; 2) identify intraoperative risk factors that contribute to increased critical care requirements; and 3) develop a new model taking into account intraoperative factors to refine our risk stratification algorithm to maximize patient safety and minimize waste of critical care resources. Patients and Methods No outside funding was received for this study and the study was approved and conducted according to the guidelines set forth by our Institutional Review Board (IRB). We identified 1594 consecutive patients who underwent an elective total hip or knee arthroplasty procedure at a single, high-volume, academic institution from January 2012 through February 2013. Using a prospectively collected patient database, we identified all patients who were admitted to the ICU during the study period. Patients were risk stratified to postoperative The Journal of Arthroplasty xxx (2014) xxx–xxx The Conflict of Interest statement associated with this article can be found at http:// dx.doi.org/10.1016/j.arth.2014.02.028. Reprint requests: Gwo-Chin Lee, MD, Department of Orthopaedic Surgery, Penn Presbyterian Medical Center, Philadelphia, PA 19104. 0883-5403/0000-0000$36.00/0 – see front matter © 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.arth.2014.02.028 Contents lists available at ScienceDirect The Journal of Arthroplasty journal homepage: www.arthroplastyjournal.org Please cite this article as: Courtney PM, et al, Predictors of the Need for Critical Care After Total Joint Arthroplasty: An Update of Our Institutional Risk Stratification Model, J Arthroplasty (2014), http://dx.doi.org/10.1016/j.arth.2014.02.028