Point of Care Testing/Central Laboratory Analysis of Glucose and Electrolytes in Diabetic Emergencies. Are They Comparable?

Abstract

Prompt diagnosis of electrolytes and acid-base abnormalities in diabetic emergencies, and quick intervention is the key to a good outcome. In the Third world, there is a delay in reporting of central laboratory results due to a mirage of problems. POCT testing has been shown to be valuable in the management of diabetic emergencies as it provides quick results and expedite treatment. To find out in this study if there was an agreement between the analytes evaluated with central laboratory and Abbot I-STAT point of care. A prospective comparison of paired venous blood samples with Abbot I-STAT POCT testing and central laboratory (ion-selective electrode, SFRI analyzer ISE 6000) measurements were obtained from 30 diabetic patients. There was good agreement with electrolytes and glucose values between Abbot I-STAT POCT analyser and SFRI ISE 6000 analyser in diabetic emergencies. The Lin's concordance correlation (agreement) for glucose (p_c) =0.999, mean difference of 0.04 mmol/L and 95% limit of agreement (LOA) from -4.702 to +4.622 mmol/L, p = 0.986. Sodium (p_c) =0.996, mean difference of 0.027 mmol/L and 95% LOA from -0.191 to +0.245 mmol/L, p = 0.991. Potassium (p_c) = 0.990, mean difference of 0.03 mmol/L, and 95% LOA from -0.032 to +0.078 mmol/L, p =0.919. Chloride (p_c) =0.996, mean difference of -0.04 mmol/L and 95% LOA from -0.197 to +0.284 mmol/L, p = 0.983. Bicarbonate (p_c) =0.949, mean difference of 0.37 mmol/L and 95% LOA from -0.49 to +1.23mmol/L, p = 0.832. Blood urea nitrogen (p_c) =0.999, mean difference of 0.12 and 95% limit of agreement from -0.501 to +0.254mmol/L, p = 0.202. PCV (p_c) =0.483, mean difference of -3.7% and 95% LOA -7.78 to +0.40, p= 0.991. The agreement  between central laboratory testing and I-STAT Abbot point of care testing was good for electrolytes and glucose.

Keywords: POCT, Central laboratory, Bland Althmans, Diabetic emergencies.