Risk Factors for Postoperative Fever and Systemic Inflammatory Response Syndrome After Ureteroscopy for Stone Disease

Introduction: Infectious complications after ureteroscopy (URS) for stone disease lead to emergency department visits, hospitalizations, and other costly health care utilization. The objective of our study was to identify risk factors for postoperative fever (POF) and systemic inflammatory response syndrome (SIRS) after URS for stone disease. Materials and Methods: We performed a retrospective cohort study on 2746 patients who underwent 3298 URS for stone disease at Geisinger from 2008 to 2016. A univariate analysis tested the associations between candidate demographic, preoperative, and intraoperative predictors and the primary outcome of POF (temperature >100.4°F) or SIRS. Variables with a p-value of <0.05 on univariate comparisons were entered into a random-effects logistic regression model. The final model used backward elimination random-effects logistic regression to identify predictors most predictive of POF/SIRS. Results: Overall, 229 (6.9%) of 3298 URS had POF/SIRS. On univariate analysis, individuals with POF/SIRS were older, had higher mean body mass index, higher Charlson Comorbidity Index (CCI), bilateral and larger stones, stone location in the kidney, positive preoperative urine culture, pre-stented, and longer surgical times. In the final model, female gender (adjusted odds ratio [OR] 1.6, 95% confidence interval [CI] 1.19-2.15), surgical time (adjusted OR 1.01, 95% CI 1.0-1.01), CCI ≥2 (adjusted OR 1.86, 95% CI 1.29-2.67), and positive preoperative urine culture (adjusted OR 1.53, 95% CI 1.06-2.22) were the most significant predictors of POF/SIRS. Conclusions: Female gender, longer surgical time, medical complexity, and positive preoperative urine culture are associated with POF/SIRS after URS. These data may be used to identify and counsel high-risk individuals.