tailieunhanh - Chapter 036. Edema (Part 5)

This syndrome, which occurs almost exclusively in women, is characterized by periodic episodes of edema (unrelated to the menstrual cycle), frequently accompanied by abdominal distention. Diurnal alterations in weight occur with orthostatic retention of NaCl and H2O, so that the patient may weigh several pounds more after having been in the upright posture for several hours. Such large diurnal weight changes suggest an increase in capillary permeability that appears to fluctuate in severity and to be aggravated by hot weather. There is some evidence that a reduction in plasma volume occurs in this condition with secondary activation of the. | Chapter 036. Edema Part 5 Idiopathic Edema This syndrome which occurs almost exclusively in women is characterized by periodic episodes of edema unrelated to the menstrual cycle frequently accompanied by abdominal distention. Diurnal alterations in weight occur with orthostatic retention of NaCl and H2O so that the patient may weigh several pounds more after having been in the upright posture for several hours. Such large diurnal weight changes suggest an increase in capillary permeability that appears to fluctuate in severity and to be aggravated by hot weather. There is some evidence that a reduction in plasma volume occurs in this condition with secondary activation of the RAA system and impaired suppression of AVP release. Idiopathic edema should be distinguished from cyclical or premenstrual edema in which the NaCl and H2O retention may be secondary to excessive estrogen stimulation. There are also some cases in which the edema appears to be diuretic-induced. It has been postulated that in these patients chronic diuretic administration leads to mild blood volume depletion which causes chronic hyperreninemia and juxtaglomerular hyperplasia. Salt-retaining mechanisms appear to overcompensate for the direct effects of the diuretics. Acute withdrawal of diuretics can then leave the Na -retaining forces unopposed leading to fluid retention and edema. Decreased dopaminergic activity and reduced urinary kallikrein and kinin excretion have been reported in this condition and may also be of pathogenetic importance. Idiopathic Edema Treatment The treatment of idiopathic cyclic edema includes a reduction in NaCl intake rest in the supine position for several hours each day and the wearing of elastic stockings which should be put on before arising in the morning . A variety of pharmacologic agents including angiotensin-converting enzyme inhibitors progesterone the dopamine receptor agonist bromocriptine and the sympathomimetic amine dextroamphetamine have all been .