Long-term urethral catheterization increases risk of chronic pyelonephritis and renal inflammation.

OBJECTIVE: To determine the prevalences of chronic pyelonephritis and chronic renal inflammation in elderly nursing home patients at the time of death and to assess correlation with urethral catheterization and other putative risk factors.
DESIGN: Prospective assessment of risk factors with the prevalences of chronic pyelonephritis and renal inflammation at autopsy.
SETTING: A 240-bed long-term care facility. PARTICIPANTS: All residents > or = 65 years old who died and were autopsied during a 2-year period. MEASUREMENTS: Antemortem assessment of risk factors for renal inflammation, including a search for any urethral catheterization in the person's life. Prospective assessment of urethral catheterization, catheter obstruction, and use of anti-inflammatory medications and urine cultures. Urinary tract pathology was assessed for gross and microscopic evidence of inflammation and urinary tract stones.
RESULTS: The duration of catheterization was significantly associated with increasing prevalence of bacteriuria, polymicrobial bacteriuria, chronic pyelonephritis, and chronic renal inflammation. The prevalence of chronic pyelonephritis at death was 10 percent (5/52) for patients catheterized > 90 days during their last year of life and zero (0/65) when catheterized < or = 90 days (P < 0.02; Fisher's exact test). Chronic pyelonephritis was significantly associated with renal stones and hydronephrosis. The prevalence of chronic renal inflammation without chronic pyelonephritis was significantly greater than that of chronic pyelonephritis: the prevalence was 43 percent (20/47) when catheterized > 90 days and 18 percent (12/65) when < or = 90 days (P < 0.05). Chronic renal inflammation was associated with hydronephrosis, ureteral dilatation, acute pyelonephritis and diastolic hypertension.
CONCLUSION: Chronic pyelonephritis and chronic renal inflammation are associated with long-term catheterization.