A comparison of arterial blood glucose and peripheral blood glucose levels in critically ill patients: measurements using the arterial blood gas analyzer and the rapid glucose meter

BACKGROUND This study explored the differences, correlation, and consistency between blood glucose levels measured using an arterial blood gas analyzer and a rapid blood glucose meter in critically ill patients. METHODS A total of 73 critically ill patients admitted to the Department of Critical Care Medicine, from October to December 2016 were enrolled in this study. The patient's arterial blood glucose was measured by arterial blood gas analyzer, while peripheral blood glucose was measured by a rapid blood glucose meter (via the non-infusion limb). The correlation between indicators was analyzed using the linear regression model. Bland-Altman was performed to evaluate the agreement of the two methods for measuring blood glucose. P<0.05 was considered statistically significant. RESULTS The blood glucose values measured using the arterial blood gas analyzer was significantly different from the values obtained using the rapid blood glucose meter (P=0.000). Regression analysis showed that R2 was 0.857 and β was 0.324 (P=0.000). Bland-Altman plot analysis showed that arterial blood glucose values obtained using the arterial blood gas analyzer were higher than the peripheral blood glucose values obtained using the rapid blood glucose meter on the non-infused limb, with 2.74% of dots lying outside the 95% limit of agreement and the maximum absolute value (2.30 mmol/L) of blood glucose difference within the limit of agreement. The blood glucose levels measured using the two different methods showed good agreement. CONCLUSIONS The difference in blood glucose values measured using the two different measurement methods was statistically significant, but the maximum absolute value (2.30 mmol/L) of blood glucose difference within the limit of agreement, which is acceptable in the clinical setting. In clinical care, it is not necessary to repeat a measure of the patient's capillary blood glucose (CBG) using the rapid blood glucose meter after the blood glucose levels have been measured with the arterial blood gas analyzer, thereby reducing the associated pain and inconvenience for the patients.