Oxygen derived variables in acute respiratory failure

摘要: The clinical course of 33 patients with acute respiratory distress syndrome (ARDS) was monitored by noninvasive oxygen derived variables and compared to data obtained invasive monitoring. A total 350 points were used compare the physiologic shunt fraction (Qsp/Qt) ratio arterial inspired concentration (PaO2/FIO2), alveolar-arterial pressure difference [P(A-a)O2], index (RI)-[P(A-a)O2/PaO2], alveolar (a/A). PaO2/FIO2 ratio, RI aA correlated well Qsp/Qt (r = 0.87 0.94). P(A-a)O2 less 0.68). Changes in cardiac (CI) arteriovenous content C(a-v)O2 had only a minimal effect on correlation Qsp/Qt, although higher resulted when these extrapulmonary factors within normal range. We conclude that number may accurately reflect degree Qsp/Qt. is easiest calculate, yet predicts throughout failure.