부산대학교 도서관

In mechanically ventilated patients with acute circulatory failure related to sepsis, we investigated whether the respiratory changes in arterial pressure could be related to the effects of volume expansion (VE) on cardiac index (CI). Forty patients instrumented with indwelling systemic and pulmonary artery catheters were studied before and after VE. Maximal and minimal values of pulse pressure (Ppmax and Ppmin) and systolic pressure (Psmax and Psmin) were determined over one respiratory cycle. The respiratory changes in pulse pressure (Δ Pp) were calculated as the difference between Ppmax and Ppmin divided by the mean of the two values and were expressed as a percentage. The respiratory changes in systolic pressure (Δ Ps) were calculated using a similar formula. The VE-induced increase in CI was ≥ 15% in 16 patients (responders) and < 15% in 24 patients (nonresponders). Before VE, Δ Pp (24 ± 9 versus 7 ± 3%, p < 0.001) and Δ Ps (15 ± 5 versus 6 ± 3%, p < 0.001) were higher in responders than in nonresponders. Receiver operating characteristic (ROC) curves analysis showed that Δ Pp was a more accurate indicator of fluid responsiveness than Δ Ps. Before VE, a Δ Pp value of 13% allowed discrimination between responders and nonresponders with a sensitivity of 94% and a specificity of 96%. VE-induced changes in CI closely correlated with Δ Pp before volume expansion (r = 0.85, p < 0.001). VE decreased Δ Pp from 14 ± 10 to 7 ± 5% (p < 0.001) and VE-induced changes in Δ Pp correlated with VE-induced changes in CI (r = 0.72, p < 0.001). It was concluded that in mechanically ventilated patients with acute circulatory failure related to sepsis, analysis of Δ Pp is a simple method for predicting and assessing the hemodynamic effects of VE, and that Δ Pp is a more reliable indicator of fluid responsiveness than Δ Ps.