Hematocrit Causes the Most Significant Error in Point of Care Glucometers
Abstract
The study by Hoedemaekers et al (1) has failed to identify the most likely and proven confounder for accuracy of point-of-care (POC) glucometers used in the intensive care unit: hematocrit. A cursory review of the literature reveals that the effect of low patient hematocrit is to systematically elevate measurements in single-channel POC glucometers (2, 3). The whole blood samples used by all single-channel POC glucometers fail to account for reduced plasma displacement by fewer red blood cells, thus artificially elevating the reported glucose value. This problem is exacerbated by the simultaneous adoption of tight glucose control (4, 5) and restrictive transfusion practices (6) in many hospitals that use POC glucometers (7). Application of the recommendation by Hebert et al for permissive anemia effectively decreases hematocrit to the range of approximately 21%. Our research has identified the level of unacceptable performance of single-channel POC glucometers to occur at 34% hematocrit (8). We have developed a simple mathematical correction formula for the top four POC devices used in the United States that reduces the substantial inaccuracy caused by anemia to a margin of error less than 5% from the reference laboratory value (8).
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 2009
- Accession Number
- ADA632234
Entities
People
- Charles E Wade
- Elizabeth A. Mann
- Heather Pidcoke
- John B Holcomb
- Josè Salinas
- Steven Wolf
Organizations
- United States Army Institute of Surgical Research