Pseudo-renal failure with hyponatremia and proteinuria after gynecologic surgery: a case report with literature comparison.

backgroundAcute kidney injury (AKI) is defined by an increase in serum creatinine according to the Kidney Disease: Improving Global Outcomes criteria. In contrast, pseudo-renal failure is a rare condition characterized by azotemia and electrolyte imbalance that mimic AKI, while the actual renal function remains preserved. Because of its rarity and nonspecific presentation, pseudo-renal failure is often misdiagnosed as true AKI. We report a rare case of pseudo-renal failure caused by intraperitoneal bladder rupture following gynecologic surgery. This case is unique in that pseudo-renal failure was accompanied by severe hyponatremia and nephrotic-range proteinuria despite the absence of significant glomerular pathology, highlighting an important diagnostic pitfall. CASE PRESENTATION: A 49-year-old woman presented with progressive renal dysfunction and persistent mild lower abdominal discomfort two weeks after total laparoscopic hysterectomy with bilateral salpingo-oophorectomy for uterine leiomyoma. Laboratory tests revealed markedly elevated blood urea nitrogen (68.2 mg/dL) and creatinine (4.48 mg/dL), with relatively preserved cystatin C (1.34 mg/L), severe hyponatremia (123 mmol/L), and nephrotic-range proteinuria (7.9 g/day). A kidney biopsy was performed to evaluate for an underlying glomerular disease; however, it revealed only minor glomerular changes with no significant pathological abnormalities. Abdominal ultrasonography revealed moderate ascites without other remarkable findings. To investigate the cause of the ascites, diagnostic paracentesis was performed, which revealed an ascitic creatinine level higher than the serum creatinine level, suggesting urinary ascites. Consequently, computed tomography (CT) cystography confirmed urinary leakage caused by intraperitoneal bladder rupture. The patient underwent the surgical repair following Foley catheter placement. Her renal function normalized postoperatively, with resolution of hyponatremia and a reduction in proteinuria.

conclusionsThis case highlights the importance of recognizing pseudo-renal failure as a differential diagnosis of unexplained azotemia, particularly in patients with recent pelvic surgery. The coexistence of elevated serum creatinine with relatively preserved cystatin C, ascites, hyponatremia, and nephrotic-range proteinuria should raise suspicion for urinary tract injury. Measurement of ascitic fluid creatinine and CT cystography are key diagnostic tools for genitourinary trauma that can prevent unnecessary invasive procedures and guide timely therapeutic interventions. Ultimately, awareness of this entity enables prompt diagnosis and favorable clinical outcomes for patients.