Pink Film on Foley Catheter Tubing and Bag
Clinical Significance
A pink film on Foley catheter tubing and bag represents bacterial biofilm formation, most commonly indicating Purple Urine Bag Syndrome (PUBS), which signals bacterial colonization of the catheter system and requires immediate catheter replacement. 1
Immediate Management
Replace the catheter and drainage system immediately to remove the discolored equipment and reduce bacterial biofilm burden. 1 This is the primary intervention recommended by the American College of Physicians for managing this condition.
Key Management Steps:
Use the smallest appropriate catheter size (14-16 Fr for adults, with 16 Fr being standard) to minimize urethral trauma during replacement. 1, 2
Maintain a closed urinary drainage system at all times and keep the drainage bag below bladder level to prevent urine from recirculating back into the urinary collection system. 1
Perform regular dressing exchanges at the catheter exit site to maintain cleanliness and reduce infection risk. 1
Understanding the Biofilm Problem
The pink/purple discoloration reflects polymicrobial biofilm formation on the catheter surfaces. 3 These biofilms develop rapidly after catheter insertion and contain diverse bacterial assemblages, typically including both Gram-positive and Gram-negative organisms. 3
Bacterial colonization occurs soon after placement of urinary devices, with subsequent encrustation of debris and solutes forming an intraluminal complex biofilm over time. 4 This biofilm protects bacteria from antimicrobials and the host immune response, making treatment challenging.
Common organisms involved include:
Critical Management Pitfalls to Avoid
Do NOT Treat Asymptomatic Bacteriuria
Avoid surveillance urinary cultures and antimicrobial treatment of asymptomatic patients, as this promotes multidrug-resistant organisms without clinical benefit. 4, 1 This is a common error—in one surveillance study, 70% of antimicrobial treatments were inappropriately given for asymptomatic bacteriuria rather than symptomatic infection. 6
Do NOT Add Antimicrobials to Drainage Bags
Routine addition of antimicrobials or antiseptics (including hydrogen peroxide, chlorhexidine, or povidone-iodine) to the drainage bag should not be used, as randomized trials have shown no benefit in reducing catheter-associated bacteriuria or urinary tract infections. 4, 7 These interventions are ineffective because infections arising intraluminally from drainage bag contamination are uncommon. 7
Do NOT Use Prophylactic Systemic Antibiotics
Prophylactic antimicrobials should not be administered routinely at the time of catheter placement, removal, or replacement to reduce catheter-associated bacteriuria. 4
Long-Term Catheter Management
For patients requiring ongoing catheterization:
Schedule routine catheter exchanges every 3 months (or more frequently if high risk for obstruction) to prevent urinary tract infections and device obstruction. 4, 1
Consider chlorhexidine-impregnated dressing changed weekly for patients with recurrent urinary tract infections or frequent exit site infections. 4, 1
Avoid concomitant use of Foley catheters with other urinary devices (such as percutaneous nephrostomy tubes or ureteral stents) when feasible. 4
When to Treat with Antibiotics
Only treat if the patient develops symptomatic urinary tract infection with clinical manifestations such as fever, dysuria, suprapubic pain, or systemic signs of infection. 4, 6 The presence of bacteria in urine or discoloration of the catheter system alone does not warrant antimicrobial therapy.