What to do when a patient passes blood while flushing a urinary catheter?

Blood Return During Urinary Catheter Flushing

Stop flushing immediately and assess for catheter malposition, bladder trauma, or underlying pathology causing hematuria—the blood is likely from urethral trauma during insertion, bladder irritation, or indicates the catheter has migrated into vascular tissue.

Immediate Assessment and Action

Do not continue flushing when blood returns, as this may indicate:

• Catheter malposition - The catheter tip may have migrated into the bladder wall, prostate bed, or rarely into a vascular structure 1
• Traumatic insertion - Urethral or bladder mucosal injury during catheterization, though catheter-induced hematuria is typically minimal (fewer than 4 RBCs per high-power field in most cases) 2
• Bladder pathology - Pre-existing conditions such as bladder tumors, stones, or severe cystitis that are now manifesting 3

Evaluation Steps

Assess the volume and character of blood:

• Small amounts of blood-tinged urine may represent minor trauma from catheter irritation of the bladder wall or urethra 1, 3
• Frank blood or clots suggest more significant injury or pathology requiring immediate intervention 3
• Persistent bleeding beyond initial catheterization is abnormal and warrants investigation 2

Check catheter position and patency:

• Ensure the catheter balloon is properly inflated within the bladder and not in the urethra 1
• Verify the catheter has not been inserted too deeply, which can cause coiling or knotting within the bladder 1
• Confirm the catheter is draining appropriately when not being flushed 3

Management Based on Findings

For minimal blood-tinged urine (self-limiting):

• This is common with suprapubic and urethral catheters and typically resolves spontaneously 3
• Monitor drainage and ensure catheter patency 3
• Avoid aggressive flushing that may worsen mucosal trauma 4

For persistent or significant hematuria:

• Do not flush aggressively - Use gentle technique with a 10 mL or larger syringe to avoid excessive pressure that could damage tissue 5
• Consider catheter repositioning or replacement if malposition is suspected 1
• Obtain urine culture if infection is suspected as a contributing factor 3, 4
• Evaluate for underlying pathology (imaging, cystoscopy) if bleeding persists beyond 24-48 hours 3

Flushing Technique When Necessary

If flushing is required for catheter patency:

• Use sterile 0.9% sodium chloride for flushing 5, 6
• Always use a 10 mL or larger syringe to prevent excessive pressure that could perforate or damage tissue 5
• Apply gentle, steady pressure—never force flush against resistance 5
• Maintain sterile technique with appropriate hand hygiene and personal protective equipment 5

Common Pitfalls to Avoid

• Never apply excessive pressure during flushing - This can cause catheter rupture, bladder perforation, or worsen mucosal injury 5
• Do not ignore persistent hematuria - While minor trauma is common, significant or ongoing bleeding requires investigation 2, 3
• Avoid repeated traumatic flushing attempts - If resistance is met, evaluate for catheter obstruction or malposition rather than forcing fluid through 5, 1
• Do not assume all hematuria is benign - Catheterization causes minimal hematuria; more than 3-4 RBCs per high-power field suggests other pathology 2

Prevention Strategies

• Use appropriate catheter size and lubrication during insertion to minimize urethral trauma 2
• Ensure proper catheter positioning with balloon inflation only after urine return confirms bladder placement 1
• Implement proper catheter care protocols to prevent irritation and infection 3, 4
• Limit catheter duration to reduce risk of complications including bleeding and infection 3, 4