Presentation at AVA Nursing Conference Outlines Research in Comparative Effectiveness of Vascular Devices

The type of IV connector used in vascular access is closely linked to a patient's chance of getting a dangerous bloodstream infection, according to two new studies.

The studies compared several different types of needleless IV connectors (devices that connect IV catheters to tubing and help deliver medications and nutrition).

A zero displacement IV connector outperformed other connector designs in two different studies that were statistically significant, according to a scientific poster presented at the annual conference of the Association for Vascular Access.

The studies in the poster were intended to determine if there was a connector design that would not "defeat healthcare workers if they don't use the devices correctly, whether it is disinfecting the device or flushing the device," the authors stated.

There is a much higher risk of infection with connectors that are highly dependent on technique or have other design flaws, the authors said.

"Both of our studies showed that connector design played a significant role in outcomes," said poster author Denise Macklin BSN, RN-C. "This is an important finding, because few clinicians fully understand the safety differences between the various connector types available today. We see unsafe designs persisting and inadequate awareness of safer options."

Reducing catheter-related bloodstream infections (CRBSI) is a high priority in vascular access. Approximately 250,000 bloodstream infections occur annually in U.S. hospitals, according to the CDC. The attributable treatment cost can be as much as $56,000 per incident, the CDC says, with these infections killing an estimated 12% to 20% of patients who get them.

The conference poster reported results from an in vitro study and a comparative effectiveness study. The studies compared several different kinds of IV connectors including designs known as split septum, negative displacement, positive displacement and zero displacement.

The comparative effectiveness research involved paired "t-tests" in various hospital settings, in which a zero displacement connector was compared to three other connector designs. A t-test is a research method used for determining whether the means of two groups are statistically different from each other. CRBSI rates were recorded before and after adoption of the zero displacement device.

The mean infection rate for the zero-displacement device was substantially better (lower) than a split septum connector, negative displacement connector, and positive displacement connector. The study encompassed five hospital settings in six states.

The comparative effectiveness study encompassed nearly 122,000 catheter days. The zero displacement device was used for a total of 65,653 of those days. Researchers calculated that its use meant 125 infections were avoided. Savings from the avoided infections totaled more than $4 million, assuming about $32,000 in treatment costs per infection.

Besides the zero displacement device, the connector types tested in the in vitro study were a split septum connector, two neutral displacement connectors, and a positive displacement device. All of the connectors were inoculated with four organisms associated with CRBSI and then tested after bovine blood withdrawal and medication (saline) delivery, to simulate clinical conditions. The connectors were also periodically disinfected and flushed.

A mean of only 0.15 colony-forming units (CFUs) per day was found on the zero displacement device. A CFU is a measure of viable cells.

The next best-performing device, a positive fluid displacement connector, had 367% more CFUs. Two negative displacement connectors had more than 1000% more CFUs than the InVision-Plus. The worst performer was a split septum connector.

The poster was titled "Product as a Significant Variable in Vascular Access Research: Comparing In Vitro and Clinical Studies Outcomes of IV Connectors." Macklin's co-author on the study was Cynthia C. Chernecky, R.N., Ph.D., AOCN, FAAN.

The zero displacement InVision-Plus® IV connector examined in the two studies is made by RyMed Technologies. The Annual Scientific Meeting of the Association for Vascular Access was held Oct. 16-19 in San Antonio, Texas.