Risk factors for post-obstructive diuresis following surgical correction of ureteropelvic junction obstruction in pediatrics: A retrospective cross-sectional study.

BACKGROUND

Post-obstructive diuresis (POD) is a potentially serious complication following surgical correction of ureteropelvic junction obstruction (UPJO) in pediatric patients. Characterized by excessive urine output after decompression of a chronically obstructed renal system, POD may result in significant fluid and electrolyte imbalance. While physiologic POD is transient, pathologic forms require careful management. This study aimed to determine clinical and demographic risk factors associated with POD following UPJO surgery in a pediatric population.

METHODS

We conducted a retrospective cross-sectional study of pediatric patients undergoing UPJO correction at two tertiary centers in Mashhad, Iran, from July 1, 2020, to July 1, 2021. Data were extracted from hospital records, including age, sex, hydronephrosis grade, presence of renal tubular acidosis (RTA), serum creatinine, and anemia status. POD was defined as urine output >4 mL/kg/h for three consecutive hours postoperatively. Statistical analyses included Chi-square tests and independent t-tests; p < 0.05 was considered significant.

RESULTS

A total of 360 patients were included (65 % male; mean age: 62.2 ± 18.3 months). POD occurred in 22 patients (6.1 %). Patients with POD were significantly younger (mean age: 50.3 ± 10.7 months vs. 63.2 ± 18.6 months; p < 0.001) and more frequently presented with Grade 4 hydronephrosis (81.8 % vs. 45.6 %; p = 0.001). No significant associations were found between POD and sex (p = 0.435), RTA (p = 0.683), serum creatinine levels (p = 0.509), or anemia (p = 0.347).

CONCLUSION

Younger age and severe hydronephrosis were significantly associated with increased risk of POD after surgical correction of UPJO. These findings underscore the importance of close postoperative monitoring in high-risk pediatric populations. Prospective studies with standardized POD criteria are needed to validate these predictors and optimize perioperative care.