How Do You Calculate Plasma Osmolarity?
Osmolarity is a measure of the concentration of the solutes in a solution, and is measured in moles of solute particles in a given volume of solution. Plasma osmolarity refers specifically to the osmolarity of blood plasma and typically measures only specific solutes. It is a common diagnostic tool for identifying electrolyte imbalances, especially low blood sodium (hyponatremia). Plasma osmolarity may be calculated from the concentrations of the individual solutes. Obtain the concentrations for the solutes you wish to calculate the plasma osmolarity for. The most common solutes of interest include sodium (Na+), glucose and blood urea nitrogen (BUN). Convert mg/dl to the standard units of millimoles per liter (mmol/L). To convert deciliters to liters, multiply by 10. To convert milligrams to millimoles, divide by the molecular weight. Therefore, to convert mg/dl to mmol/L, multiply by 10/Ds, where Ds is the molecular weight of the solute s. Calculate 10/Ds where Ds is the molecular wei
