Glucose meters are a mature technology that has been used for more than three decades by patients and healthcare providers in settings far and wide. However, as meters—designed for patient self-monitoring and validated primarily on ambulant, well patients who happen to have diabetes—have been used with hospitalized and even critically ill patients, some problems have arisen, writes James H. Nichols, PhD, DABCC, FACB, in the May issue of CLN.

Hospitalized patients present with extremes of hematocrit, pH, and perfusion that challenge glucose meter performance. They also often are on intravenous drug and oxygen therapies that pose potential for interferences not found in patient self-management. Recent incidents with maltose interference and a specific glucose meter methodology led to death in several hospitalized patients.

These concerns caused Food and Drug Administration (FDA) to respond in two ways: 1) to add a sentence to the limitations section of all glucose meter package inserts that meters have not been evaluated in critically ill patients; and 2) to release, in January 2014, draft guidance on Blood Glucose Monitoring Test Systems for Prescription Point-of-Care Use. The latter describes the studies that FDA recommends for manufacturers who intend to submit premarket notifications (510k) for blood glucose meters. Although FDA’s guidance was directed at glucose meter manufacturers, the New York State Department of Health responded almost immediately with a letter to laboratories warning about off-label use of glucose meters.

The Centers for Medicare and Medicaid Services (CMS) also issued a similar warning letter last November, which it temporarily withdrew, reissued it as a draft with draft clarifications, and requested comments on the draft guidance. These advisories and warnings have left hospitals and laboratories uncertain as to how they should proceed. Nichols, who chairs AACC’s Government Relations Committee, advised that staff can continue to use glucose meters, provided they stay within the package insert recommendations. Alternatively, hospitals can limit glucose testing to non-critical patients and use blood gas analyzers or send samples to the central lab for critically ill patients. Labs should talk to their clinicians, define the “critically ill” population for their specific meter and institution, and ensure use within each manufacturer’s recommendations. CMS has noted that further clarification is forthcoming, but until then, labs should ensure that their actions, by either continuing to use the meters or discontinuing use, first and foremost do not harm patients.

Pick up the May issue of CLN to read more about concerns with glucose meters and critically ill patients.