When to Escalate
Why the Device Changes Infection Risk
An indwelling urinary catheter creates a direct route between the external environment and the bladder.
An indwelling urinary catheter creates a direct route between the external environment and the bladder. Bacteria can move along the outside of the catheter at the urethral meatus or enter the drainage system and travel through the catheter lumen. Once organisms attach to the catheter surface, they can form a biofilm: a protective microbial layer that makes organisms harder to remove and can support their ascent into the bladder. Gram-negative bacilli, including Escherichia coli, are common causes. The longer the catheter remains in place, the longer bacteria have to establish this foothold. CAUTI prevention therefore begins before insertion. The safest catheter is the one that is never inserted, and the next safest is the one removed promptly.