Decreased serum angiotensin converting enzyme in adult respiratory distress syndrome associated with sepsis: a preliminary report.

Serum angiotensin converting enzyme (ACE) levels were obtained in 24 control patients who were critically ill, in 11 patients with cardiogenic pulmonary edema, in 8 patients with status postcardiopulmonary bypass, and in 12 patients with adult respiratory distress syndrome (ARDS). Mean values in cardiogenic pulmonary edema (24.3 +/- 3.9 SD) in cardiopulmonary bypass (19.5 +/- 3.1) and in patients with ARDS and no sepsis (n = 7, 19.0 +/- 5.5) were not significantly different from controls (20.7 +/- 2.8). In contrast, patients with ARDS and sepsis had markedly decreased serum ACE levels which fell outside of control range (n = 5, 8.6 +/- 2.3). The authors speculate that decreased ACE levels in the combination of sepsis and ARDS are due to the presence of circulating inhibitors of ACE. The finding of decreased serum ACE can be of potential clinical usefulness by raising the possibility of sepsis as the etiology of ARDS before results of blood cultures are available.