The difference between the glucose concentrations in plasma and whole blood

Steroid Concentrations in Plasma, Whole Blood and Brain: Effects of Saline Perfusion to Remove Blood Contamination from Brain

“…Similarly, in humans, most cortisol is found in the plasma, bound to CBG [9]. This issue has been well-studied with regard to glucose, which is also present at higher levels in plasma than whole blood [33]. This issue is particularly important for studies comparing circulating and local levels of steroids, because the difference between circulating and local steroid concentrations could be miscalculated.…”

Glucose Measurement: Confounding Issues in Setting Targets for Inpatient Management

“…In general, manufacturer specifications describe limitations in methodologies under these conditions, but the clinician must be aware that POC devices are not capable of excluding such samples. Furthermore, based on simple regression analyses, the conversion between plasma and whole blood is dependent on the glucose level itself and may vary considerably at extremes of glucose measurement (76,80). Whole blood may be tested with the POC meter but converted to equivalent plasma glucose values obtained from donor blood samples supplemented with glucose; therefore, measurements of plasma samples are inaccurate on such devices (81).…”

Comparison of bedside and laboratory blood glucose estimations in critically ill children with shock

“…In the present study, laboratory assay was done on plasma, and the glucometer measured glucose in whole blood filtered through a filter and gave results in "plasma equivalence" by applying a correction factor. This may be a major reason for differing glucose concentration in plasma and whole blood samples (16). Although there are limitations in obtaining good capillary samples from critically ill patients, this study demonstrates that capillary whole blood glucose values correlate well with values from a laboratory in pediatric patients in shock.…”