Regulation of renal function in thermal injury

Hypovolemia, low cardiac output, and systemic vasoconstriction are major etiologic factors in acute renal failure occurring in the early postburn period, and elevated levels of stress-related hormones (catecholamines, angiotensin, aldosterone, and vasopressin) are implicated in the mechanism. By counteracting the effects of the hormones, atrial natriuretic polypeptide (ANP) regulates the renal response to burns. ANP was elevated after burns, protecting the kidneys by increasing renal blood flow and urine output. In pulmonary acid injury, increased ANP levels were associated with natriuresis which was reduced by administration of anti-ANP serum. Exogenous ANP given to dogs under constant norepinephrine infusion resulted in improvement of hemodynamic and renal parameters. To prevent tubular damage due to hemoglobinuria, a haptoglobin preparation is administered to patients with extensive third-degree burns. With sufficient fluid replacement, these new treatments will reduce the incidence of acute renal failure in the early postburn period.