Mechanisms of Edema Formation

Caution must be applied in using diuretics for the treatment of edema in nephrotic syndrome. Edema in some forms of nephrotic syndrome, particularly in minimal change disease, may be due primarily to hypoalbuminemia causing an arterial underfilling of the kidneys (see the tutorial on pathophysiology of edema formation). Consequently, diuretic use may precipitate shifts in plasma volume leading to effective ciculating volume depletion. Some forms of nephrotic syndrome, however, have an element of overfilling due to avid sodium reabsorption by the kidneys. Regardless of the mechanism for edema formation, the patient in whom diuretics are used to treat edema must be monitored closely for signs of volume depletion.