Yes, urine output can decrease to minimal amounts in a Foley bag a few hours after TURBT, and this represents a potentially serious complication requiring immediate evaluation.
Minimal or absent urine output after TURBT should prompt urgent assessment for bladder outlet obstruction from blood clots, catheter malposition, or—rarely but critically—bilateral ureteric orifice obstruction by the catheter balloon.
Mechanism and Clinical Context
Post-TURBT oliguria or anuria can occur through several pathways:
Primary Causes to Evaluate:
Catheter obstruction from clot retention is the most common culprit. TURBT creates a raw bladder surface that bleeds, and clots can occlude the catheter eyes or lumen, preventing drainage despite adequate urine production 1, 2, 3.
Catheter balloon malposition can obstruct the bladder neck or, in rare cases documented in the literature, actually compress the ureteric orifices bilaterally. A case report 4 demonstrated that after transurethral resection, an overinflated catheter balloon (30 mL) caused bilateral ureteric obstruction, resulting in anuria and acute kidney injury. Deflating the balloon to 10 mL and repositioning immediately restored urine flow.
Bladder perforation during resection can lead to extravasation and reduced intravesical urine collection, though this typically presents with other signs like abdominal pain or distension 1, 2, 3.
Immediate Assessment Algorithm
When faced with minimal urine output post-TURBT:
Assess catheter patency first: Attempt gentle manual irrigation with 30-60 mL saline. Resistance or inability to flush/aspirate suggests clot obstruction.
Check catheter position: Ensure the catheter hasn't migrated. If the balloon is inflated with >20 mL, consider deflating to 10-15 mL, especially if the trigone was involved in resection 4.
Evaluate for systemic signs: Check vital signs, assess for flank pain (suggests ureteric obstruction), abdominal distension (suggests perforation or extravasation), and review fluid balance.
Laboratory assessment: Obtain creatinine if anuria persists beyond 1-2 hours, as acute obstructive uropathy can rapidly impair renal function 4.
Imaging if needed: Bedside ultrasound can identify hydronephrosis (ureteric obstruction) or free fluid (perforation). CT may be warranted if diagnosis remains unclear.
Common Pitfalls
Assuming all decreased output is from dehydration: While patients may have reduced oral intake perioperatively, true anuria or severe oliguria (drops per minute) is pathologic and demands investigation.
Over-inflating the catheter balloon: Standard practice uses 10-15 mL for a three-way catheter post-TURBT. Larger volumes (20-30 mL) increase risk of trigonal compression and ureteric obstruction, particularly when normal anatomy has been disrupted by resection 4.
Delayed recognition of bilateral obstruction: This rare complication can cause rapid deterioration in renal function. The key clinical clue is anuria with flank pain in the absence of other obvious causes 4.
Expected Post-TURBT Course
Normal post-TURBT urine output should be adequate (typically >0.5 mL/kg/hr) with continuous bladder irrigation running clear to light pink. Complications occur in approximately 8% of cases, with retention affecting 2.8% of patients 3. Most complications are minor (Clavien-Dindo grade I-II), but recognition and prompt management prevent progression to serious morbidity 3.
The bottom line: A few drops per minute is not normal post-TURBT output and mandates immediate troubleshooting of the catheter system and evaluation for obstruction before assuming benign causes.