A comparative study between capillary and venous blood glucose levels of type 2 diabetes mellitus patients in intensive care units

Özet

Blood glucose estimation is required to be done rapidly or even on hourly basis for effective dosing of insulin in diabetic patients admitted in intensive care units (ICUs). Glucose test strip precision is usually considered clinically acceptable if the difference from the reference value (lab method) does not exceed 15%. With an aim to determine the correlation of capillary blood glucose versus venous blood glucose in hyperglycemic type 2 diabetes mellitus patients admitted in ICU, a study was conducted in a large tertiary care hospital. This study was a cross sectional, descriptive study which was carried out in a large tertiary care teaching hospital in Pune, from 01 Nov 2015 to 31 Oct 2016. After excluding all the confounding factors, 65 patients were included in this study. The laboratory results and glucose strip results were tabulated in a master chart as sample 1(capillary/venous- time of admission), sample 2(capillary /venous – 24 hrs), sample 3 (capillary /venous – 48 hrs) and also segregated into less than 250 mg/dl and more than 250 mg/dl for determining the correlation and agreement between the capillary and venous blood glucose levels. A good correlation existed between the CBG and VBG of sample 1 (R2 =0.995, p 250mg/dl which was (R2 =0.943, p<0.05) and (R2 =0.989, p<0.05) respectively. The capillary blood glucose values were always higher than the venous values and was within 10 -11%. The CBG and VBG levels agreed more than 95% times in all the samples. The capillary blood glucose estimation using a glucometer is a prudent alternative in ICU setting to venous blood glucose estimation by laboratory methods keeping in view that a 8-11% higher capillary blood glucose value exists .This should be taken into consideration while deciding on the insulin dosage for T2DM patients admitted in ICU who are on insulin infusion.