Desmopressin (DDAVP) is a drug used primarily for diabetes insipidus, haemophilia type A, and von Willebrand's disease.
Sodium is the major positively charged Cation in ECF. It determines ECF volume. Major intravascular ion to affect osmolality…..an acute increase or decrease in serum sodium will produce an increase or decrease in serum osmolality.
Hypernatraemia can be caused by a number of critical illnesses: water depletion (decreased intake, hypotonic fluid loss – renal/non-renal); solute excess (Na+ or other)