Relative accuracy of arterial and capillary glucose meter measurements in critically ill patients

As optimizing glucose control in critically ill patients remains a challenge for intensive-care physicians, this study aimed to determine the accuracy of glucose measurements.

The accuracy of capillary and arterial blood glucose meter measurements was compared with central laboratory arterial glucose measurements; the factors associated with inaccurate measures were also determined.

Altogether, 302 samples from 75 patients were assessed. Mean glucose levels were 126±52 mg/dL for capillary measurements, 133±50 mg/dL for arterial measurements and 143±54 mg/dL for serum glucose laboratory measurements. Compliance with the ISO 15197 guidelines was observed in 74.8% of the capillary samples and 88.7% of the arterial samples. However, all measurements by glucose meter (with either capillary or arterial samples) led to underestimations of serum glucose.

In critically ill patients, glucose measurements from capillary and arterial blood by glucose meter are inaccurate, and can potentially lead to inappropriate use of insulin-infusion protocols and failure to achieve glycaemic targets.