Isotonic hyponatremia Isotonic hyponatremia Isotonic hyponatremia is a form of hyponatremia with mOsm measured between 280 and 295. It can be associated with pseudohyponatremia, or with isotonic infusion of glucose or mannitol. Certain conditions, such as extraordinarily high blood levels of lipid (hyperlipidemia/hypertriglyceridemia) or protein (hyperparaproteinemia), magnify the electrolyte exclusion effect. This interferes with the measurement of serum sodium concentration by certain methods, leading to an erroneously low "measurement" of sodium, or pseudohyponatremia. The methods affected are the flame-photometric and indirect (but not direct) ion-selective electrode assays. This is distinct from a true dilutional hyponatremia that can be caused by an osmotic
Blood sugar level given in terms of whole blood, but most laboratories now measure and report plasma or serum glucose levels. Because red blood cells (erythrocytes) have a higher concentration of protein (e.g., hemoglobin) than serum, serum has a higher water content and consequently more dissolved glucose than does whole blood. To convert from whole-blood glucose, multiplication by 1.14 has been shown to generally give the serum/plasma level To prevent contamination of the sample with intravenous fluids, particular care should be given to drawing blood samples from the arm opposite the one in which an intravenous line is inserted. Alternatively, blood can be