Impact of early ureteral drainage on mortality in obstructive pyelonephritis with urolithiasis: an analysis of the Japanese National Database

Abstract

Background: The impact of early drainage on mortality in patients with obstructive pyelonephritis with urolithiasis was evaluated.

Methods: We identified 34,924 patients in the Japanese Diagnosis Procedure Combination database with obstructive pyelonephritis with urolithiasis receiving ureteral drainage. The effects of early drainage (1-2 days) compared to those of delayed drainage (on 3-4 and ≥ 5 hospital days) on mortality were evaluated among 31,696 patients hospitalized for ≥ 5 days. Multivariate analysis was performed to identify independent factors for mortality.

Results: The mortality rates for overall cases and those hospitalized for ≥ 5 days were 2.0% and 1.6%, respectively. Those receiving drainage on 1-2, 3-4, and ≥ 5 days had mortality rates of 1.5%, 2.0%, and 2.5%, respectively (p < 0.001). Multivariate analysis revealed that delayed drainage was an independent factor for higher mortality (odds ratio [OR] on days 3-4 and ≥ 5; 1.44, p = 0.018; and 1.69, p < 0.001). Increasing age (OR for 60 s, 70 s, and ≥ 80 years; 2.02, 3.85, and 7.77), Charlson comorbidity index score (OR, 1.41 by 1-point increase), disseminated intravascular coagulation (OR, 2.40), ambulance use (OR, 1.22), impaired consciousness at admission (disoriented, arousable with stimulation, and unarousable; OR 1.58, 2.84, and 5.50), and nephrostomy (OR, 1.65) were associated with higher mortality. In contrast, female sex (OR, 0.76) and high hospital volume (OR on 9-16, and ≥ 17 cases/year; 0.80, and 0.75) were associated with lower mortality.

Conclusion: Ureteral drainage within 2 hospital days was an independent factor for low mortality in obstructive pyelonephritis with urolithiasis. Delayed drainage could increase mortality in a time-dependent manner.

Keywords: Drainage; Hospital volume; Mortality; Obstructive pyelonephritis; Ureteral calculi.