A 38-year-old female, gravida 7, para 3, living 3, abortus 3 (G7P3L3A3) at 28 weeks of gestation with a monochorionic, diamniotic twin pregnancy underwent emergency lower segment caesarean section (LSCS) for pre-eclampsia. She was also a known case of gestational diabetes mellitus (GDM). Although her intra-operative course was uneventful, on POD 4, she developed gradually progressive and persistent abdominal pain, distension, with tenderness on palpation. A new-onset fever was noted with urine output of 250 ml over the past 24 hours. Her lab investigations on POD 4 revealed elevated C-reactive protein (CRP, 180 mg/L), and urine analysis showed leukocytes 50-100 per high-power field and positive leukocyte esterase, suggestive of UTI. Renal function tests revealed a serum creatinine of 3.4 mg/dL and BUN of 133 mg/dL. Contrast-Enhanced CT (CECT) abdomen and pelvis revealed significant free fluid in the peritoneal cavity with evidence of intraperitoneal extravasation of contrast at the dome of the bladder (Figure 1). A pigtail catheter was inserted for ascitic fluid drainage. The normal bladder anatomy is shown in the figure below (Figure 2).
Figure 1: Intraperitoneal extravasation of contrast and a clear defect in the dome of the bladder (black arrow) (Image courtesy: www.radiopaedia.org)
Figure 2: Normal bladder anatomy
Wrong Answer: A. This case scenario is suggestive of uroperitoneum secondary to injury of the left posterior bladder wall
Explanation: Most urinary tract injuries post obstetric/gynecological surgeries remain undetected intra-operatively. Clinical presentation of a urinary bladder injury depends on both mechanism and time elapsed since surgery. Common signs and symptoms include fever, ileus, persistent abdominal pain or distension, haematuria, oligo-anuria, and unilateral or bilateral flank pain.
Wrong Answer: B. Peritoneal fluid can be assessed as being urine by analysis of peritoneal fluid for creatinine level.
Explanation: B. Peritoneal fluid can be assessed as being urine by analysis of peritoneal fluid for creatinine level.
Right Answer: C. The acute kidney injury that this patient has developed is due to post-renal cause of urinary obstruction/retention.
Justification: Considering this was a high-risk pregnancy that had to undergo emergency LSCS for pre-eclampsia, she has developed a urinary bladder injury at the dome of the bladder. Contrast-Enhanced CT (CECT) abdomen and pelvis revealed significant free fluid in the peritoneal cavity with evidence of intraperitoneal extravasation of contrast at the dome of the bladder, indicative of a urinary bladder injury (Figure 1). . Although urinary obstruction/retention and uroperitonitis are contributory causes of deranged RFT for this patient, the primary reason for the rapid rise in creatinine is reverse auto-dialysis. When urine enters the peritoneal cavity, reverse autodialysis occurs. Urea and creatinine migrate down their concentration gradients into the blood, giving a distinctive biochemical profile of pseudo-renal failure. This appears within 24 hours of undetected bladder rupture. The significant early spike in creatinine reflects peritoneal urine resorption rather than genuine acute renal failure. The drop in urine output is also attributable to multifactorial causes, which include urinary obstruction/retention, uroperitonitis, and urinary bladder injury.
Clinical Pearls Detection and Presentation: Most urinary tract injuries post-surgery go undetected; symptoms depend on injury type and timing, including fever, abdominal pain, and haematuria. · Diagnosis: Uroperitoneum confirmed by elevated creatinine, urea, and potassium in ascitic fluid; CECT abdomen/pelvis is the imaging gold standard. · Reverse Autodialysis: Undetected bladder rupture can cause “pseudo-renal failure” as urine in the peritoneum leads to a rapid serum creatinine spike within 24 hours. · Surgical Repair: Repair depends on injury site and severity; dome injuries heal well, while complex trigone injuries may need ureteral stenting.
Wrong Answer:D. Considering the site of injury, urinary bladder wall repair is the definitive management of choice.
Explanation: The surgical repair of bladder injuries is determined by the anatomical location (dome, supratrigonal region, trigone, and subtrigonal area), the nature of the injury (e.g., perforation, laceration, thermal injury), and the degree of the injury (figures 1 and 2).
Figure 1: Bladder anatomy Figure 2: Types of bladder injury
Dome or supratrigonal injuries are typically healed with excellent results. Due to the anatomical intricacy of the trigone, repairs of trigone defects or other injuries are typically conducted by specialised gynaecologic or urologic surgeons. The trigone is located in the inferior and posterior region of the bladder, encompassing the openings of the ureters and urethra. Injuries to or just below the trigone may affect the ureters or urethra, are more challenging to treat than dome or supratrigonal injuries, and may necessitate ureteral stent implantation to avert ureteral obstruction. Considering the findings of CECT abdomen and pelvis, our patient has a grade 4 bladder injury involving the dome of the bladder. Other management considerations for this patient include close monitoring of renal function and electrolytes, antibiotic therapy tailored to culture results to manage UTI and sepsis, daily drainage monitoring, and CRP levels to evaluate infection control.