Nephrostomy tube related pyelonephritis in patients with cancer: epidemiology, infection rate and risk factors.

PURPOSE: Nephrostomy tube placement is often necessary to avert acute renal failure in patients with cancer with obstructive uropathy or in patients with ureteral leak. However, there have been limited published studies on the rate and risk of nephrostomy tube related pyelonephritis in patients with cancer. Therefore, in this study we determined rates of nephrostomy tube related pyelonephritis and predisposing risk factors in patients with cancer.
MATERIALS AND METHODS: We retrospectively reviewed patients who underwent nephrostomy tube placement between September 1, 2009 and September 16, 2010 at MD Anderson Cancer Center. Patients were followed for 90 days. The primary outcome assessed was the development of nephrostomy tube related pyelonephritis and the secondary outcome was the development of asymptomatic bacteriuria. We also determined risk factors associated with pyelonephritis.
RESULTS: Of the 200 patients analyzed 38 (19%) had pyelonephritis and 15 (7.5%) had asymptomatic bacteriuria. Of the nephrostomy tube related infections 34 cases (89%) were with the primary nephrostomy tube. Subsequently 4 of the patients who underwent nephrostomy tube exchange had an episode of pyelonephritis. Pyelonephritis developed within the first month in 19 (10%) patients. Prior urinary tract infection and neutropenia were found to be significant risk factors for pyelonephritis (p = 0.047 and 0.03, respectively).
CONCLUSIONS: The placement of nephrostomy tubes in patients with cancer is associated with a significant rate of pyelonephritis. Neutropenia and history of urinary tract infection were significant risk factors for pyelonephritis. This finding warrants further investigation into preventive strategies to reduce the infection rate.