New attention on POC device disease transmission

Another barrier to proper disinfection: using the right disinfectant. “Conventionally, alcohol wipes have been used to wipe down the meters, but those are not adequate,” Dr. Geaghan says. “Only bleach solutions are effective in killing viruses such as hepatitis B. And yet bleach is corrosive to many point-of-care instruments. So for the time being, there’s a problem with using the disinfectant that’s most effective and maintaining integrity of the instrumentation.”

At least one manufacturer concurs that bleach and other disinfecting wipes are a problem where device integrity is concerned. “Most meters are designed with an outer plastic shell,” says Mary C. Coyle, MS, MT(ASCP), director of POC hospital marketing for Roche Diagnostics. “The disinfectants that are used to kill the bugs take the elasticity out of that plastic, and you now have brittle plastic. So the area where the plastic would come into contact with the base unit would look like a windshield shatter—it would show cracks.”

The FDA has taken notice of this issue, Dr. Geaghan says. “They’ve written a letter to manufacturers, telling them that for the next generation of point-of-care instruments, they will be required to demonstrate in a more rigorous fashion that their disinfection protocols address these issues, and that their instrument design also takes these issues into account.”

As for the vendors themselves, they’re responding to infection transmission concerns in different ways. For example, Nova, which manufactures the StatStrip Connectivity and StatStrip Xpress point-of-care glucose analyzers, emphasizes the design of its glucose strip. “As long as one follows the procedures recommended in the instructions, the amount of blood obtained by skin puncture should be minimal, and therefore the risk of contamination is minimal,” says medical and scientific affairs vice president Jeffrey A. DuBois, PhD. “In our case, it’s 1.2 mL that’s metered into the strip. That’s not a lot of blood. And so the risk of transferring the patient’s blood to the meter is actually minimal. If the user follows procedure by wiping the meter down between each patient, there should be minimal risk.”

What about device degradation due to disinfection? “We don’t get a high number of returns due to disinfecting with bleach,” Dr. DuBois says. “Some products have that problem. I don’t think ours have had that problem.”

He adds that Nova manufactures a disposable cover that can be used with the StatStrip on patients in isolation: “So the risk of transmitting an infectious agent is minimal, because you use the protective overlay. The user should dispose of that and the strip in the patient’s room, to leave all the potentially biohazardous material within that patient’s isolation space.”

Meanwhile, Abbott, which manufactures the Precision Xceed Pro Blood Glucose and b-Ketone Monitoring System, stresses the role of its individually packaged testing strips in preventing the transmission of infection. “The test strips for the Precision Xceed Pro System are individually foil-wrapped to reduce the chances of test strips becoming contaminated by bacteria commonly found in hospitals,” says Mani Gopal, PhD, general manager of Point-of-Care for Abbott Diabetes Care. “In fact, they are the only individually packaged test strips in the POC glucose testing industry.”

Test strips that are packaged in quantity and stored in opened vials, Dr. Gopal says, have a higher risk of contamination. He points to a letter to the editor in the American Journal of Infection Control that said an investigation of vial-packaged test strips found that 25.7 percent of them tested positive for bacteria (Vanhaeren S, et al. Am J Infect Control. 2011;39:611–613). In this study, dedicating a vial to a single patient did not change the strip contamination rate.

As for Roche, in October it launched the Accu-Chek Inform II POC blood glucose meter, which, Coyle says, was designed to resist degradation by bleach and other disinfecting wipes. For example, to prevent the bar-code scanner window from falling off, it’s been attached to the inside of the device rather than clipping on from the outside. In addition, says Coyle, “We took out every possible opening that would allow liquid ingress into the meter, so that it’s not accumulating body fluid.” Finally, she adds, the top of this instrument has been made completely flat: “Previous generations had an indent where the screen was, and so to get disinfectant into those corners was sometimes a cause for concern. By making it a fully flat meter, it’s easier to clean.”

Regardless of the brand and type of POC devices they use, hospitals must consider the CDC’s recommendation that they assign each patient a single POC device, to be used exclusively on that patient during the entire length of stay and to be disinfected upon that patient’s discharge. In Dr. Geaghan’s view, most hospitals are reluctant to do this. “What I’m hearing is that they do not think this is realistic due to the capital investment required,” she says. “In addition, the cost of running additional controls for each additional meter is a recurring incremental cost.” On the other hand, she points out, “There are many unforeseen costs to the transmission of disease, which is the written position of the CDC in response to the increased-cost-of-care argument.” There are also the potential legal ramifications. “So I think it remains to be seen what level of adoption is really going to occur. At this point, it does not seem that the majority of institutions are heeding this recommendation.”

Anne Ford is a writer in Evanston, Ill.