Genitourinary infections in the patient at risk: extrinsic risk factors.

The indwelling urinary catheter is an essential part of modern medical care. It is widely used to relieve temporarily anatomic or physiologic urinary obstruction, to facilitate surgical repair of the urethra and surrounding structures, to provide a dry environment for comatose or incontinent patients, and to permit accurate measurement of urinary output in severely ill patients. Unfortunately, when poorly managed, the indwelling catheter may present a hazard to the very patients it is designed to protect. It is the leading cause of nosocomial induced urinary tract infections and the most common prediposing factor in fatal gram-negative sepsis in hospitals. Catheters drain the bladder, but they obstruct the urethra, producing other major problems such as urethral strictures and epididymitis. Advances in catheter care since the introduction of closed drainage are reviewed. The best means of prevention is the avoidance of use when unnecessary and prompt removal when the need no longer exists. This practice is of particular importance in long-term care institutions. Alternate methods include intermittent catheterization in the paraplegic patient, condom drainage in the nonobstructed patient, and direct drainage of the bladder through the skin. Most recent studies have attempted to improve care of the indwelling catheter by either prevention of periurethral infection (the most common route of acquisition) or sterilization of the drainage bag to prevent ascending infection and cross infection. Thus far, these methods have been unsatisfactory. A new approach to designing drainage systems is clearly needed. Finally, all studies failed to demonstrate the ability of systemic antimicrobial therapy to eradicate catheter-associated infections other than temporarily. Instead, excessive use of antibiotics has led to the emergence of resistant strains that may be spread to other patients through contaminated urine.