What is the purpose of irrigating a Foley (urinary) catheter?

From the Guidelines

Irrigating a Foley catheter with saline is the first recommended attempt to restore catheter patency in cases of intra-lumen catheter occlusion. When a blockage occurs, causing poor urine drainage, irrigation of the Foley catheter is necessary to maintain patency and prevent complications. According to the ESPEN practical guideline on clinical nutrition in chronic intestinal failure 1, the first attempt to restore catheter patency should be forceful irrigation of the catheter with saline.

Key Considerations for Irrigation

• The procedure should be performed using a sterile closed irrigation system with normal saline (0.9% sodium chloride) to minimize the risk of infection.
• Sterile technique is crucial: the catheter port should be cleansed with an alcohol swab before connecting a sterile syringe containing 30-50 mL of normal saline to the irrigation port.
• The solution should be gently instilled, then withdrawn along with any debris.
• It is essential not to force fluid if resistance is met, as this could damage the bladder or urethra.
• The irrigation should be repeated until the fluid returns clear or the blockage resolves.

Management of Specific Occlusions

• For non-thrombotic occlusions, treatment depends on the primary etiology: lipid occlusion is treated with 70% ethanol or sodium hydroxide, mineral precipitates are treated with 0.1 N hydrochloric acid (HCl), and drug precipitates are treated according to their pH.
• For thrombotic occlusion, fibrinolytic drugs such as urokinase and alteplase are recommended, with a dwell time of at least 30 minutes and repeated doses if necessary 1.

Preventing Complications

• Routine irrigation is not recommended due to the increased risk of infection.
• Irrigation is justified when maintaining catheter patency, managing blood clots after urological procedures, or clearing debris that obstructs urine flow.
• Documentation of the procedure, including the amount of fluid instilled and retrieved, and the character of the returned fluid, is essential for monitoring and adjusting treatment as needed.

From the Research

Irrigating Foley Catheter

• The purpose of irrigating a Foley catheter is to prevent catheter obstruction, fevers, and/or bacteremia, as well as to maintain the patency of the catheter 2.
• However, a study published in 1989 found that once-daily irrigation with normal saline of long-term urethral catheters had no significant impact on the morbidity associated with such catheters, including catheter obstructions and febrile episodes 3.
• Another study from 1978 found that irrigation with saline or 0.25% acetic acid had no effect on urinary bacterial count, while irrigation with 0.02% chlorhexidine or 0.25% silver nitrate effectively reduced bacterial counts 4.
• In contrast, a 2018 study found that daily bladder irrigation with normal saline solution decreased the risk of catheter-associated urinary tract infections (CAUTI) by 99% in comatose patients with short-term indwelling urinary catheterization 5.
• It is essential to follow evidence-based guidelines for the placement and removal of urinary catheters to prevent CAUTIs, including using aseptic technique and limiting the use and duration of catheter placement 6.

Best Practices for Irrigation

• Manual and continuous bladder irrigation can be performed to restore or maintain the patency of an indwelling urinary catheter, and best practices should be followed to prevent adverse events 2.
• The choice of irrigating solution is crucial, with some solutions (e.g., chlorhexidine, silver nitrate) being more effective than others (e.g., saline, acetic acid) in reducing bacterial counts 4.
• The frequency and duration of irrigation may also impact its effectiveness, with daily irrigation for 3 days showing promise in preventing CAUTIs in comatose patients 5.