Application of established pathophysiologic processes brings greater clarity to diagnosis and treatment of hyponatremia

Figure 7 Effect of isotonic infusion in patient with syndrome of inappropriate anti-diuretic hormone in whom blood volume determination by ⁵¹chromium-labeled red blood cells and radio iodinated serum albumin was increased. Note persistently increased urine osmolality or failure of urine to become dilute or correction of hyponatremia which are common features of SIAD response to isotonic saline infusion. Printed with permission, Ref. [13]. SIADH: Syndrome of inappropriate anti-diuretic hormone; SNa: Serum sodium; Uosm: Urine osmolality.