Blood glucose at the point of care: The current controversies surrounding inpatient blood glucose monitoring.

In by Heather DelCarpini

MARCH 16, 2016

Blood glucose at the point of care: The current controversies surrounding inpatient blood glucose monitoring.

Andrew Rhinehart, MD, FACP, FACE, CDE, BC-ADM, Chief Medical Officer with Glytec, and Melanie Mabrey, DNP, ACNP-BC, BC-ADM, CDTC, FAANP, Vice President of Clinical Practice with Glytec, discuss barriers that impact the accuracy and dependability of blood glucose measurements in hospitalized patients and alternatives to point of care blood glucose meters.

The timely and accurate determination of blood glucose in the hospital setting is critical to effective nursing workflow and improved patient care. The results have a direct impact on the delivery of insulin and, ultimately, glycemic control. With roughly 25% of people admitted to the hospital experiencing hyperglycemia and the improved outcomes proven to occur with appropriate glycemic management, more and more hospitals, providers and patients are struggling with the recent controversies surrounding inpatient blood glucose monitoring.

Advances in blood glucose monitoring technology have been astounding, but despite this fact, several barriers exist regarding the accuracy and dependability of blood glucose measurements in hospitalized patients. One of the many difficult aspects of glycemic management in the hospital is the timing of point-of-care (POC) blood glucose (BG) testing, insulin administration and meals. The workflow surrounding this aspect of care is essential to optimizing blood glucose control and overall patient care. Either nurses or nursing assistants, depending upon the facility, perform POC testing, and this can further complicate the process. When each of the three responsibilities: meal delivery, POC testing and insulin administration are done by different individuals, the coordination of the three can be difficult and opportunities for failure abound.

There are multiple indications for the use of IV insulin, but its use is often limited to intensive care units (ICU) and emergency departments (ED); however, some institutions with experience and confidence in their inpatient glycemic management programs allow for the use of IV insulin infusions in non-ICU areas. IV insulin protocols usually require hourly glucose tests to make timely dose adjustment to prevent hypoglycemia and maintain glucose levels within a target range. These hourly glucose tests can stress the nursing staff and may require workflow adjustments. For any IV insulin dosing algorithm, whether paper or computerized, to be safe and efficacious, there is the need for simplified processes, including workflow and testing procedure, to obtain an accurate POC BG result with rapid test turnaround times. In addition to insulin administration and diabetes treatment requirements is the need for cost effectiveness and ease of workflow.

The CMS and the FDA mandates are currently causing concern, confusion and angst across the country as institutions struggle to provide patient care while trying to comply with what many feel are unreasonable regulations surrounding the use of POC BG meters in critical care areas. At present, no POC BG meter is cleared by the FDA for capillary fingerstick use in critically ill patients. If institutions make the decision to allow POC BG meters in this manner, it will be considered an off-label use. Thus, the use of these meters in critically ill patients will not be considered waived by the Clinical Laboratory Improvement Amendments (CLIA), but instead a high-complexity test. High complexity CLIA testing has much more stringent requirements, including the need to validate and establish institutional performance specifications, more frequent competency testing for staff and may only be conducted by registered nurses or lab technicians. These requirements make this option financially unrealistic and prohibitive. CMS is threatening to cite hospital labs if POC fingerstick capillary blood testing is performed in this setting without meeting the CLIA high complexity requirements.

If hospitals decide against establishing high complexity CLIA standards and using POC BGMs off-label, the other options for critically ill patients are:

  • Blood gas analyzers, such as i-STAT.
  • Nova Biomedical StatStrip: POC BGM FDA cleared for use in “critically ill patients,” but not for fingerstick capillary blood. It can only be used with venous or arterial blood and neonatal heelstick blood.
  • Non-strip blood analyzers: HemoCue, Piccolo Xpress and YSI glucose analyzer.
  • Central laboratory BG measurements with a 30-60 minute turnaround time.

Unfortunately, these alternatives can be wrought with workflow, cost and clinical barriers that make their use difficult. When used in truly critically ill patients, POC BG meters using fingerstick capillary blood may be unreliable, as they often report lower glucose values than laboratory glucose results. The conditions listed below make the use of POC BG meters a relative contraindication:

  • poor peripheral perfusion
    • sepsis
    • severe dehydration
    • shock
    • vasopressor
    • diabetic ketoacidosis (DKA)
    • nonketotic hyperosmolar conditions
  • hypoxemia
  • gross edema
  • severe anemia
  • polycythemia vera

Several of the aforementioned conditions can occur in non-critically ill patients. Therefore, limiting the fingerstick POC BG meter use in critically ill patients does not consistently eliminate use of POC testing when laboratory testing would be more appropriate. Additionally, limiting the use of POC BG meters in critically ill patients excludes the use in patients that may be in an ICU setting, but do not have any of the relative contraindications listed above. Moving forward, it is essential that providers and institutions understand that critically ill does not equate with being in an intensive care unit. Policies must be developed to define a “critically ill patient,” with whom the use of fingerstick capillary blood via a POC BG meter may be a relative contraindication. The list above serves as a starting point in developing such a definition; however, the outlined alternatives to POC BG meters will require significant workflow planning, purchasing considerations and clinical discussion. Most importantly, instead of threatening citations and fines, CMS and FDA must collaboratively work with hospitals and clinicians to develop better alternatives to fingerstick capillary POC BG meters, which are presently serving as the best way to manage critically ill patients.

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