[ADH (anti-diuretic hormone), aldosterone (PA) and renin activity (PRA) in patients with respiratory failure]

Plasma ADH, PA and PRA in patients with respiratory failure (RF) were studied. RF patients were divided into 4 groups, i.e. acute RF (ARF) and chronic RF (CRF), with or without hypercapnia. The levels of these hormones were significantly higher in RF than those in control subjects, moreover, they were markedly elevated in ARF than those in CRF. In multiple regression analysis, ADH correlated with PaO2, pH and PRA in RF patients, but correlated with serum osmolality in control subjects. It was considered that ADH in RF was affected by the direct effect of blood gases and circulatory disorder. The mechanism of elevated PA and PRA in RF probably was mediated through restriction of intake of water and Na, reduction of renal blood flow and decreased ACE often occurred in RF. Abnormally elevated hormones are more often recognized in edematous patients than in nonedematous patients. It was suggested that many patients with RF develop heart failure or edema due to hormonal abnormalities.