Impact of timing of urinary drainage on clinical outcomes in patients with obstructive pyelonephritis associated with upper urinary tract stones: a propensity score-matched analysis

We aimed to assess the impact of the timing of urinary drainage on clinical outcomes in patients with obstructive pyelonephritis (OPN) associated with upper urinary tract (UUT) stones. We retrospectively evaluated the multicenter dataset of 240 patients with OPN associated with UUT stones who underwent urinary drainage. We divided the patients into two groups depending on the timing of urinary drainage; emergency drainage, defined as within 12 h from admission, and delayed drainage, defined as between 12 and 48 h from admission. The outcomes were the length of hospital stay, time to leukocyte normalization, and time to body temperature normalization. One-to-two propensity score matching (PSM) was applied to minimize the effect of confounders between the two groups. Subsequently, predictive patient factors for emergency drainage were analyzed using the logistic regression model. Only the time from admission to normal body temperature was significantly shorter in the emergency drainage group when compared with the delayed drainage group (median: 2 vs. 3 days; p = 0.02), while there was no difference in time from drainage to body temperature normalization between the two groups. On multivariable analysis, high pretreatment C-reactive protein (CRP) was associated with implementing emergency drainage within 12 h. The timing of urinary drainage was only associated with the duration of high fever, but it did not affect the postdrainage course. Emergency urinary drainage is more likely to be performed in severe patients, such as high pretreatment CRP.