<prompt> What is the osmolality of plasma if Serum sodium is 135 mEqL, serum glucose is 120 mgdL and BUN is 24 mgdL?276285286290  <response>: Because of the predominant role of the major solutes and the detion of plasma from an ideal solution, one can ordinarily approximate the plasma osmolality within a few mosmliter by using the following formula, in which the constants conve the clinical units to millimoles of solute per liter: Osmolality mOsmL 2 mEqL 0.055 mgdL 0.36 mgdL Ref: Ganongs Review of Medical Physiology 23rd edition, Chapter 1. 