Urinary Catheterization

A catheter-associated urinary tract infection (CAUTI) is the most common healthcare-associated infection in the U.S. — and most are preventable through nursing technique and timely removal decisions.

Urinary catheterization involves inserting a sterile catheter into the bladder to drain urine. Indwelling (Foley) catheters remain in place via an inflated balloon (typically 5–10 mL sterile water — never saline, which can crystallize and prevent deflation). Straight (intermittent) catheterization drains the bladder once and is removed immediately, carrying a lower infection risk. Strict sterile technique is non-negotiable for insertion: cleanse the urethral meatus with antiseptic, advance the catheter until urine flows, then advance another 1–2 inches before inflating the balloon to ensure it sits in the bladder, not the urethra. For females, insert 2–3 inches; for males, insert 7–9 inches at a 60–90 degree angle to navigate the prostatic urethra. Secure the catheter to the upper thigh (female) or lower abdomen (male) to prevent traction on the bladder neck. Keep the drainage bag below the level of the bladder at all times — never on the floor — and never disconnect the closed system. CAUTI prevention is driven by daily reassessment: document the ongoing indication every shift and advocate for removal as soon as possible. Maximum initial drainage should be limited to 500–1000 mL at one time to prevent rapid bladder decompression, which can cause hypotension and hemorrhage.

Key Distinctions

Don't confuse balloon inflation fluid: sterile water, never normal saline — saline crystallizes inside the balloon port. Students mix up catheter insertion depth: females 2–3 inches versus males 7–9 inches. A common error is inflating the balloon the moment urine appears; you must advance 1–2 inches beyond first urine return to confirm the balloon is fully inside the bladder, preventing urethral trauma.

Clinical Pearl

Urine flowing doesn't mean you're in the bladder yet — advance 1–2 more inches before you inflate. Balloon trauma to the urethra is the mistake you only make once.