Continuous Bladder Irrigation (CBI)

Continuous bladder irrigation is a therapeutic intervention ordered to prevent clot retention, maintain catheter patency, and promote hemostasis following transurethral procedures or in cases of severe hematuria. The clinician must understand the pathophysiology of irrigation-related complications to make prescriptive and management decisions. During monopolar TURP, non-electrolyte hypotonic solutions (glycine 1.5%, sorbitol 3.3%, or sorbitol-mannitol 2.7%/0.54%) are used because electrolyte-containing solutions would disperse monopolar electrocautery current. These solutions have osmolalities of 200-230 mOsm/kg, significantly below plasma osmolality of 275-295 mOsm/kg. Absorption occurs through open prostatic venous sinuses at rates proportional to hydrostatic pressure (irrigation bag height), duration of surgery, and number of opened venous channels. Absorbed hypotonic fluid dilutes serum sodium, causing hypo-osmolality and water movement into cells, including brain cells. Cerebral edema manifests as confusion, agitation, seizures, and ultimately herniation if uncorrected. Glycine itself acts as an inhibitory neurotransmitter in the retina and brainstem, producing transient blindness and CNS depression independent of hyponatremia. Cardiovascular effects include initial hypervolemia with hypertension and reflex bradycardia, progressing to myocardial depression and hypotension as sodium falls below 115 mEq/L. Bipolar electrosurgery permits use of...