Effects of Injury on Regulation of Water Balance,
ARMY INST OF SURGICAL RESEARCH FORT SAM HOUSTON TX
Pagination or Media Count:
Hyponatremic burn patients may have dilute plasma, concentrated urine, and some dilution of urine and suppression of plasma arginine vasopressin AVP on further dilution of plasma after a water load which is excreted in delayed fashion. These observations indicated an osmostat for AVP secretion reset 20-30 mosmkg to the left of normal in burn patients, which leads to water retention and dilutional hyponatremia. This syndrome, conforming to the description of classical secretion of antidiuretic hormone SIADH, occurs well beyond resuscitation at a time when plasma and blood volume are restored in the absence of adrenal insufficiency, renal impairment, or Na restriction. A possible occult effective volume deficit due to a shunt through the wound beds may still play a role in postburn SIADH. However, there are several points against this interpretation a a large volume of pressure deficit approx. 20 would be the expected requirement to shift the osmostat to the extent observed b blood flow to non-wound areas, when measured, has not been deficient, but normal or elevated and c glomerular filtration rate, an index of effective volume, was reported as elevated in burn patients.