Background: Out-of-hospital (OOH) emergency personnel measure serum glucose in order to determine the need for dextrose therapy. Most devices that measure serum glucose are designed to use capillary blood obtained from a finger puncture. However, OOH emergency personnel often use venous blood obtained during intravenous line (IV) placement to determine serum glucose.
Objective: To compare capillary and venous glucose measurements.
Methods: This prospective study used healthy, non-fasting volunteers. Simultaneous venous and capillary blood samples were obtained from each subject. Glucose levels were measured using a glucometer designed for capillary samples. The capillary and venous measurements were compared using a Pearson correlation coefficient. Power analysis revealed that the study had the ability to detect a difference of 15 mg/dL.
Results: Ninety-seven volunteers (56 males, 41 females) with a mean age of 37 +/- 11.9 years were enrolled. The mean capillary and venous glucose values were 104.5 +/- 20.7 mg/dL and 109.7 +/- 22.4 mg/dL, respectively. The Pearson correlation coefficient was 0.24.
Conclusions: The correlation between venous and capillary blood glucose measurements is relatively poor in this group of healthy volunteers. Further research must be conducted on patients at risk for abnormal blood glucose.