Infectious complications following conversion to buttonhole cannulation of native arteriovenous fistulas : a quality improvement report

Background : Constant-site or buttonhole cannulation of native arteriovenous fistulas (AVFs) has gained in popularity compared with rope-ladder cannulation. However, cannulating nonhealed skin might increase the risk of (AVF-related) infectious events, as suggested by small reports. Study Design : Quality improvement report. Setting & Participants : All patients on in-center hemodialysis therapy using a native AVF from January 1, 2001, to June 30, 2010. Quality Improvement Plan : Shift to buttonhole cannulation between August 2004 and January 2005. Because the infectious event rate increased after the shift, educational workshops were held in May 2008 for all nurses, with review of every step of buttonhole protocol. Outcomes : Infectious events (unexplained bacteremia caused by skin bacteria and/or local AVF infection) and complicated infectious events (resulting in metastatic infection, death, or AVF surgery) were ascertained during 4 periods: (1) rope-ladder technique in all, (2) switch to buttonhole, (3) buttonhole in all before workshops, and (4) buttonhole in all after workshops. Results : 177 patients (aged 70.4 ± 11.5 years) with 193 AVFs were analyzed, including 186,481 AVF-days. 57 infectious events occurred (0.31 events/1,000 AVF-days). The incidence of infectious events increased after the switch to the buttonhole method (0.17 [95% CI, 0.086-0.31], 0.11 [95% CI, 0.0014-0.63], and 0.43 [95% CI, 0.29-0.61] events/1,000 AVF-days in periods 1, 2, and 3, respectively; P = 0.003). This reached significance during only the second full year of buttonhole cannulation. During period 4, the incidence tended to decrease (0.34 events/1,000 AVF-days). Complicated infectious events (n = 12) were virtually restricted to period 3 (n = 11; 0.153 [95% CI, 0.076-0.273] events/1,000 AVF-days), with a significant decrease in period 4 (n = 1; 0.024 [95% CI, 0.001-0.118] events/1,000 AVF-days; RR for period 3 vs period 4, 6.37 [95% CI, 1.09-138.4]; P = 0.04). Limitations : Observational partly retrospective design. Conclusion : Intensive staff education regarding strict protocol for the buttonhole procedure was associated with a decrease in infectious events.