Passive leg raising predicts fluid responsiveness after cardiac surgery
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KeywordsMechanical Ventilation Stroke Volume Cardiac Index Pulse Pressure Volume Expansion
Passive leg raising (PLR) represents a self-volume challenge that could predict fluid response with less limitations than other methods as variation of stroke volume and pulse pressure variation. We hypothesized that the hemodynamic response to PLR is able to predict fluid responsiveness in mechanically ventilated patients after cardiac surgery.
A prospective study in a surgical ICU of a university hospital was performed. We investigated 44 patients in the immediate postoperative period after cardiac surgery while in mechanical ventilation with no spontaneous breathing activity. Fourteen patients had arrhythmias. The hemodynamic status was evaluated at baseline, after PLR and after volume expansion (500 ml HAES 130/04 infusion over 10 min). In patients without arrhythmias, the pulse pressure variation was calculated.
In 22 patients (responders), the cardiac index increased by >15% after fluid infusion. A PLR increase of cardiac index >15% predicted fluid responsiveness with a sensitivity of 95% and a specificity of 94%. In patients without arrhythmias, a respiratory variation in pulse pressure >13% predicted fluid responsiveness with a sensitivity of 92% and a specificity of 88%.
In a group of patients submitted to cardiac surgery, the changes in cardiac index induced by PLR predict fluid responsiveness in ventilated patients with higher sensitivity and specificity than respiratory variation in pulse pressure.
This article is published under license to BioMed Central Ltd.