Bismuth coating of non-tunneled haemodialysis catheters reduces bacterial colonization: a randomized controlled trial

Abstract

Background: Haemodialysis (HD) catheter-related blood stream infections are a major cause of morbidity and mortality in patients with acute and chronic renal failure.

Methods: We conducted a randomized, prospective, double-blinded trial investigating the clinical value of bismuth-coated non-tunneled HD catheters in patients in need of temporary short-term vascular access. A standard catheter (SC) was compared to a surface-modified, bismuth-film-coated catheter (FCC). After removal of the catheter for any reason, both arterial and venous lumina were rinsed and the fluid cultured for detection of bacterial colony-forming units (CFU). The catheter tip was placed in a tube containing sterile saline, sonicated and shortly centrifuged to remove debris (3 min at 1000 g). The supernatant was cultured and assayed for DNA content.

Results: Seventy-seven patients in three HD units were randomized. Thirteen patients suffered from acute renal failure, 60 patients from chronic renal failure, and four patients without renal insufficiency were treated with plasma exchange. The time to catheter removal was not significantly different between groups, with a mean of 18.5 +/- 2 days for SC and 15.1 +/- 2 days for FCC. In most cases, the reasons for catheter removal were related to no further need for extracorporeal therapy or establishment of a permanent vascular access. Six catheters for SC and four catheters for FCC were removed because of presumed infection. Bacterial colonization was significantly lower for coated catheters compared to standard catheters, both for cultured catheter tips as well as for CFU in rinse fluids (P < 0.05).

Conclusions: Surface modification with bismuth film reduces bacterial colonization of temporary non-tunneled HD catheters in a clinical trial. Larger trials with these modified catheters are justified to further investigate the effect on catheter-related infections, complications and costs.

Fig. 1

(A) Number of catheters removed for suspected infection/thrombosis. (B) Number of direct catheters with bacterial cultures >100 CFU. (C) Number of catheters with rinse fluids containing >100 CFU/ml. P < 0.05 denotes significance between groups; n.s., not significant.

Fig. 2

CFU of the cultured segments of FCC and SC catheters.

Fig. 3

Number of CFU in 10 ml rinse fluids for FCC and SC catheters.

Fig. 4

Boxplots of the DNA content of tip or shaft segments of FCC and SC catheters

Fig. 5

Median difference in CRP between the first and the last treatment with the assigned catheter. The range of the differences was for FCC, −20 to +2.7; and for SC, −4 to +11 mg/dl.