Determinants of atrial natriuretic factor in the adult respiratory distress syndrome.

We measured plasma atrial natriuretic factor over the clinical course of 12 patients with the adult respiratory distress syndrome (ARDS). A total of 33 sequential measurements were correlated with 23 hemodynamic, pulmonary, and renal parameters. Atrial natriuretic factor was found to be eight times higher than age-matched healthy control subjects (p = 0.001). Although atrial natriuretic factor correlated well with pulmonary capillary wedge pressure (r = 0.592), there was no significant relationship between right atrial pressure and plasma atrial natriuretic factor (r = 0.258). Atrial natriuretic factor was best related to pulmonary artery systolic pressure (r = 0.751). We conclude that in ARDS, plasma atrial natriuretic factor is markedly elevated and arterial levels are best determined by left atrial pressure and pulmonary hemodynamics, and not by right sided cardiac pressures. The role of increased circulating atrial natriuretic factor in the pathophysiology of ARDS is to be clarified in future studies.