The Utility of Basic Metabolic Panel Tests After Total Joint Arthroplasty

Introduction: Routine laboratory studies are often obtained daily after total joint arthroplasty (TJA) regardless of medical management. The purpose of this study was to investigate the utility of routine basic metabolic panel (BMP) tests after TJA. Furthermore, the goal was to identify factors that may predispose patients to abnormal laboratory values that require medical intervention. Methods: A retrospective review was performed on 767 patients who underwent primary TJA at a single institution. Preoperative and postoperative potassium, sodium, creatinine, and glucose values were collected along with demographic data, comorbidities, and procedural characteristics. Multivariable logistic regression models were used to determine independent risk factors for abnormal postoperative laboratory values. Results: Diabetes was associated with abnormal glucose (odds ratio [OR] 23.4, 95% confidence interval [CI] 10.7-51.0, P <.001), while chronic kidney disease was associated with abnormal creatinine (OR 3.1, 95% CI 1.7-5.8, P <.001) and potassium (OR 1.8, 95% CI 1.1-2.8, P =.014) requiring medical intervention. An abnormal preoperative laboratory value was also associated with medical treatment for each of sodium, potassium, and creatinine (all P <.001). Average number of BMP tests collected for patients who did not receive medical intervention was 2.8. This equated to $472,372.56 in total hospital charges. Conclusion: Cost containment while maintaining high-quality patient care is critical. Routine postoperative BMP tests in patients with normal preoperative values without major medical comorbidities do not contribute to actionable information. Patients with diabetes, chronic kidney disease, or with abnormal preoperative values should obtain a BMP after TJA.