Continuous Bladder Irrigation (CBI)

Continuous bladder irrigation (CBI) involves the instillation of sterile irrigating solution through a three-way urinary catheter to prevent clot formation, maintain catheter patency, and promote hemostasis following genitourinary surgery. The three-way catheter has one lumen for balloon inflation, one for drainage, and a third dedicated irrigation port. Irrigating solution, most commonly normal saline (0.9% NaCl), flows into the bladder by gravity, dilutes blood and tissue debris, and exits through the drainage lumen into a collection bag. The rate of flow is titrated to maintain light pink or clear drainage. When hypotonic solutions such as glycine or sorbitol-mannitol are used (as in monopolar TURP), fluid absorption through open prostatic venous sinuses can cause dilutional hyponatremia, a condition known as TURP syndrome. The bladder mucosa is semi-permeable, and prolonged irrigation with large volumes creates risk for systemic fluid absorption, electrolyte imbalance, and hypothermia if room-temperature solutions are used. The nurse monitors intake and output, observes drainage color and consistency, reports changes in patient status, and ensures the irrigation system remains patent and functioning.