Catheter-associated bacteriuria.

Catheter-associated urinary tract infections are the most common nosocomial infection and a frequent cause of significant morbidity, sepsis, and death. The pathogenesis is multifaceted. Most frequently, bacteria from the urethral meatus ascend to the bladder between the mucosal and catheter surfaces. Alternatively, bacteria may ascend within the drainage system following contamination of the drainage bag or disruption of the catheter tubing junction. The incidence of infection is approximately 5 to 7 per cent for each day of catheterization and closely linked to unalterable host factors such as age, female sex, and debilitating disease. Efforts to reduce the incidence of infection must begin with reduction of the frequency and duration of catheterization. Aseptic insertion of the catheter and careful maintenance of the drainage system are mandatory to prevent incidental bacterial contamination. Prophylactic, systemic, or topical antimicrobial agents and modifications of the catheter drainage system that are designed to reduce contamination are expensive and have not been shown to be efficacious for the majority of patients. Furthermore, antimicrobial prophylaxis frequently leads to outgrowth of resistant bacterial strains that are difficult to eradicate. However, antimicrobial prophylaxis warrants consideration for high-risk patients who are catheterized for a short time. If bacteriuria occurs prior to removal of the catheter, the patient should be treated with appropriate antimicrobial therapy. Urinalysis or urine cultures should be obtained following removal of the catheter to assure sterility of the urinary tract. If these guidelines are followed, the incidence and sequelae of catheter-associated urinary tract infections can be reduced.