Effects of Estimated Glomerular Filtration Rate on 30-Day Mortality and Postoperative Complications After Total Hip Arthroplasty: A Risk Stratification Instrument.

ABSTRACT

BACKGROUND: Chronic kidney disease (CKD) is a relatively common comorbidity that has been shown to adversely affect outcomes in total hip arthroplasty (THA), as well as to increase the procedure's total costs. However, the effect of different stages of kidney disease and the association of estimated glomerular filtration rate (eGFR) with perioperative THA complications are less understood. Therefore, the aims of this study were to investigate the relationships between eGFR, both as a categorical and continuous variable and 30-day outcomes and complications. METHODS: The National Surgical Quality Improvement Program database was used to identify 101,925 primary THAs between January 1, 2008, and December 31, 2016. The following outcomes were assessed 30-day mortality, 30-day major complications, 30-day minor complications, specific complications, and discharge disposition. To evaluate the effect of eGFR status on outcomes and complication, multivariate regression models were created to adjust for differences in patient demographics and comorbidities. In addition, multivariate spline regressions were developed to assess the nonlinear relationships between eGFR as a continuous variable and the outcomes of interest. RESULTS: Our study revealed that as eGFR decreases to <30 mL/min/1.73 m2, there is an increased risk for mortality and nonhome discharge (P < .05). There was an increased risk for any major complication and any minor complication as well as several specific medical complications such as transfusion and myocardial infarction (P < .05) for an eGFR of <60 mL/min/1.73 m2. Patients' eGFR had a nonlinear relationship with mortality (P = .0001), any major complication (P < .001), and any minor complication (P < .001), as well as a number of other specific medical complications. Once the eGFR, <60 mL/min/1.73 m2 the increase was exponential for mortality, major complications, and minor complications. For example, mortality increased of 900% for <15 mL/min/1.73 m2 or on dialysis, 600% for 15 to 30 mL/min/1.73 m2 and 50% for 30 to 60 mL/min/1.73 m2. Similarly, nonlinear relationships were discovered between eGFR and nonhome discharge (P < .001). CONCLUSION: Patients with lower eGFR, and in particular those with <30 mL/min/1.73 m2, are more likely to sustain medical complications and have 6 to 9 times higher mortality than patients with normal eGFR. THA patients with CKD should be appropriately counseled and advised on the risk of postoperative complications by using eGFR as a screening tool.