Defining post-obstructive diuresis following posterior urethral valve ablation

Area of Science:

• Pediatric Urology
• Neonatal Critical Care
• Nephrology

Background:

• Posterior urethral valves (PUV) are a common cause of congenital lower urinary tract obstruction in neonates.
• Management of PUV can lead to post-obstructive diuresis (POD), potentially complicating patient recovery and hospital course.
• Identifying neonates at high risk for POD is crucial for optimizing care, yet data is limited.

Purpose of the Study:

• To define an initial urine output (UOP) threshold for identifying neonatal post-obstructive diuresis (POD) following posterior urethral valve (PUV) ablation.
• To investigate the correlation between post-ablation urine output and hospital length of stay (LOS).

Main Methods:

• Retrospective chart review of neonates undergoing cystoscopic valve ablation for PUV between 2004 and 2019.
• Analysis of urine output at 4- and 24-hours post-ablation, alongside serum creatinine, electrolytes, and fluid intake.
• Logistic regression models were used to assess predictors of prolonged hospital stay.

Main Results:

• Forty patients met inclusion criteria; mean age at ablation was 11.2 days.
• Post-operative mean urine output was 4.2 ± 3.7 mL/kg/h at 4 hours and 4.5 ± 2.2 mL/kg/h at 24 hours.
• A 24-hour UOP > 3.5 mL/kg/h was associated with over 5 times the odds of a prolonged hospital stay (>3 days) (OR: 5.50).

Conclusions:

• Neonates with PUV undergoing valve ablation are susceptible to POD.
• Elevated urine output post-ablation is a significant predictor of increased hospital length of stay.
• A 24-hour UOP threshold of >3.5 mL/kg/h can serve as an initial indicator for defining POD after PUV ablation.