Factors Predicting Outcomes in Patients with Obstructive Anuria

Introduction: Obstructive anuria is a urological emergency with heterogeneous renal outcomes. We evaluated clinical and biochemical predictors of renal recovery and chronic kidney disease (CKD) development following relief of obstruction. Materials and Methods We performed a retrospective observational study of 95 patients presenting with obstructive anuria at a tertiary referral centre. Obstructive anuria was defined as urine output <100 mL/24 hours with imaging evidence of bilateral ureteric obstruction or obstruction of a solitary functioning kidney. Patients with pre-existing CKD stage ≥3 were excluded. Demographic characteristics, duration of anuria, aetiology, laboratory parameters, infection status, dialysis requirement, and post-obstructive diuresis were analysed. Decompression was achieved using double-J ureteral stenting or percutaneous nephrostomy. Renal recovery was defined as serum creatinine <1.5 mg/dL within 10 days. CKD was defined as persistent creatinine ≥1.5 mg/dL or estimated glomerular filtration rate <60 mL/min/1.73 m² at 3 months. Results Calculous obstruction accounted for 72.6% of cases and malignant obstruction for 25.3%. Renal recovery occurred in 69.5% of patients, whereas 30.5% developed CKD. On univariate analysis, age >60 years, duration of anuria >48 hours, anaemia, hyperkalaemia, infection, dialysis requirement, and absence of post-obstructive diuresis were associated with CKD. Multivariate logistic regression identified increasing age as the only independent predictor of CKD. Post-obstructive diuresis strongly predicted renal recovery. Conclusions Obstructive anuria is a potentially reversible cause of acute kidney injury. Early decompression results in renal recovery in most patients. Increasing age is the strongest independent predictor of incomplete recovery, while post-obstructive diuresis reliably indicates favorable outcome.