CAUTI Causes

Contamination when catheter is inserted or as it remains in the bladder Gain entry during manipulation of catheter or drainage system

The catheter acts as a road or a pathway for microbes to travel and take them to possible destinations of the urethra (associated with urethritis), bladder (cystitis), kidneys (pyelonephritis) and sometimes the bloodstream (bacteremia or sepsis). In men, they may travel to the prostate (associated with prostatitis) or testicles (orchitis). Contamination can happen at the time of insertion and via extraluminal and intraluminal pathways. Pathogens can gain entry during movement of the catheter or the drainage system.

 

Common Pathogens

•E. coli •Candida •Enterococcus •Klebsiella •Associated with biofilms: –Proteus –Pseudomonas sp.

 

While most common pathogens are enteric in origin, such as E. coli, Pseudomonas, Enterococcus, Staph aureus, Enterobacter, and even yeast can cause infection. Proteus and Pseudomonas species are most commonly associated with biofilms that can protect colonizing bacterial growth from treatment.

It’s important to remember that drainage bags act as a storage container for a team of microorganisms (some of which may be multi-drug resistant). They can contaminate the environment and other patients if proper guidelines for bag emptying and hand hygiene are not followed.

 

 Extraluminal Contamination

•Bacteria (near the outside of the catheter insertion site) attach and travel upward. •These endogenous bacteria are found at the urethral meatus, the rectum and vagina. •Bacteria enter when catheter is not inserted using aseptic technique. •Bacteria travel upward after 1-3 days due to capillary action.

Let’s take a look at causes of contamination, starting with external or “extraluminal” contamination. Bacteria that are near the outside of the catheter insertion site attach and travel upward. These are endogenous bacteria and are found at the urethral meatus, the rectum and vagina.

Bacteria are given a chance to enter when the catheter is inserted using a non-aseptic technique.

And bacteria can travel upward after 1-3 days due to capillary action.

Two-thirds of all microbial migration occurs in this extraluminal way. Care interventions to prevent extraluminal contamination include assuring aseptic technique during insertion, hand hygiene, cleansing periurethral meatus daily, and secure catheter tubing.

 

Intraluminal Contamination

Internal or intraluminal contamination occurs when bacteria enters through a break (opening) in the closed drainage system.

Microbes can colonize in the drainage bag and then travel into the bladder when urine in the bag is refluxed retrograde.

Microbes can also be introduced when the tubing is disconnected from the catheter.

About one-third of microbial migration takes place in this fashion-the inside lumen of the catheter from the bag or drainage tube connection that becomes contaminated. Exogenous bacteria are found on your hands and on the equipment used for patient care.

Strategies to prevent intraluminal contamination include performing the proper maintenance of the closed drainage system, emptying the drainage bag at regular intervals, using a separate collection container for each patient, and keeping the drainage bag below the level of the bladder to prevent reflux.

 Rick Fields-Gardner