Catheters Continue to Be Linked to Most Bloodstream Infections in Dialysis Patients

Newly reported data representing nearly all US outpatient dialysis facilities reveal that most bloodstream infections in dialysis patients continue to occur in those with central venous catheters used for vascular access. The findings, which are published in a recent Clinical Journal of the American Society of Nephrology study, come from the first year of data used by the Centers for Medicare & Medicaid Services to assess facility performance based on bloodstream infections.


Increasing attention is being paid to reducing vascular access–related infections in dialysis patients. “Hemodialysis patients are at high risk for infections, which increase mortality, hospitalization, and healthcare costs. Therefore, surveillance of infectious adverse events among hemodialysis patients is very important,” said the Centers for Disease Control and Prevention’s (CDC’s) Duc Bui Nguyen, MD, lead author of the study. “Tracking infections helps guide intervention and prevention efforts to reduce severe events.”

In the late 1990s, the CDC initiated a system to help facilities track infections among dialysis patients. In the early years, a relatively small number of dialysis facilities participated. Today, though, thousands of facilities report to the CDC’s National Healthcare Safety Network (NHSN) Dialysis Event Surveillance. This is in part due to requirements set in 2012 that all Medicare licensed outpatient dialysis facilities report access-related infections to the NHSN.

Also, in 2014, bloodstream infections were added to the Centers for Medicare & Medicaid Services’ End-Stage Renal Disease Quality Incentive Program to assess dialysis facility performance.

In their recent analysis, Nguyen and his colleagues at the CDC summarized 2014 data submitted to the NHSN Dialysis Event Surveillance program. They noted that 6005 outpatient hemodialysis facilities reported data for a total of 160,971 dialysis events including 29,516 bloodstream infections (BSIs); 149,722 intravenous antimicrobial starts; and 38,310 episodes of pus, redness, or increased swelling at the hemodialysis access site. Across event types, pooled rates were highest for central venous catheters, lower for arteriovenous grafts, and lowest for arteriovenous fistulas. 


The team found that 77% of BSIs were related to accessing patients’ blood. Most—63% of BSIs and 70% of access-related BSIs—occurred in patients with a central venous catheter.

BSI and other dialysis event rates were also highest among patients using central venous catheters. Staphylococcus aureus was the most commonly isolated BSI pathogen (31%), and 40% of S. aureus isolates tested were resistant to the antibiotic methicillin. Vancomycin was the antimicrobial started in 76% of intravenous antibiotic initiations.

Hospitalization was an outcome for 22% of all dialysis events, including 49% among central venous catheter events, 36% among arteriovenous fistula events, 15% among arteriovenous graft events, and 0.4% among other vascular access events. Hospitalizations occurred in 48% of BSIs, 46% of access-related BSIs, 25% of vascular access infections and 11% of local access site infections. Death occurred in 1352 (0.8%) of all dialysis events. Two percent of BSIs and 1.6% of access-related BSIs resulted in deaths.

“We now have a clearer picture of the rates and types of infections hemodialysis patients in the United States are experiencing—nearly all US outpatient hemodialysis facilities are participating in CDC’s NHSN Dialysis Event Surveillance,” said Nguyen. “Our findings emphasize the need for hemodialysis facilities to improve infection prevention and vascular access care practices.”

In an accompanying editorial, Dana Miskulin, MD, of the Tufts University School of Medicine, and Ambreen Gul, MD, of Dialysis Clinic Inc., noted that a major problem to the available data is that event reporting is based on an honors system, and dialysis units report their own information without any processes to ensure that events are reported accurately. “We make a plea to the dialysis community to ‘clean up’ the data, so that the Quality Improvement Program is fairer for all and to enable the full potential of these data, both for improving care now and for generating new evidence to provide future opportunities to improve care and outcomes, to be realized,” they wrote.

The authors of the editorial also noted that the nearly 50% decline in rates of bloodstream and localized vascular access infections observed from 2006 to 2014 reflects improved practices; however, several red flags suggest that underreporting of events is likely. They also pointed to several unanswered questions, including whether outcomes are superior with catheter removal/replacement vs. ‘treating through,’ whether replacement over a wire is equivalent, and whether antibiotic locks have any role to play.

August 2017 (Vol. 9, Number 8)

References

1. Nguyen Duc Bui, et al. National Healthcare Safety Network (NHSN) Dialysis Event Surveillance Report for 2014. Clin J Am Soc Neph 2017; 12(6).

2. Miskulin Dana and Gul Ambreen. Infection monitoring in dialysis units: a plea for ‘cleaner’ data. Clin J Am Soc Neph 2017; 12(6).