Predictors for the Failure of Expectant Management for the Spontaneous Passage of Ureteral Calculi

ABSTRACT

PURPOSE: Ureteral calculi are commonly encountered in the emergency department. Ureteral calculi influence the quality of life of patients, causing pain and economic burden. The optimal management of ureteral calculi remains a challenge for practicing physicians; therefore, this study was designed to determine which factors are related to the failure of their spontaneous passage. METHODS: This study was a retrospective review of the medical records of one hundred ninety-five patients who visited the emergency department complaining of renal colic from February 2012 to December 2012. Bivariate analyses were conducted relating physical, laboratory, and radiological methods to predict the failure of spontaneous passage. A multivariate logistic regression model was then derived, with all variables in the final model significant at p<0.05. RESULTS: One hundred twenty-eight stones were spontaneously expelled and sixty-seven were not. The mean stone size was significantly larger in the non-passage group than the passage group (p<0.001). When the stones were located in the upper ureter, or on the right side, the spontaneous passage rate was lower (p<0.001, p=0.035). Increased neutrophils and positive tests for urinary protein and bilirubin were also associated with the decreased likelihood of spontaneous passage (p=0.046, p=0.029, and p=0.048, respectively). In addition, the longer duration of symptoms and a previous history of ureteral calculi were related to a lower chance of spontaneous passage (p=0.005, p=0.019). CONCLUSION: Prognostic factors of failure, after the initial expectant management of ureteral calculi, included calculi size, location (e.g., side), the duration of symptoms, the previous history, neutrophil levels, urinary bilirubin levels, and urinary protein levels. Therefore, emergency physicians need to cautiously decide between watchful waiting and interventions in these patients.