Positive end-expiratory pressure (PEEP)–induced increase in central venous pressure (CVP) has been suggested to be a robust indicator of fluid responsiveness, with heart rhythm having minimal influence. We compared the ability of PEEP-induced changes in CVP with passive leg raising (PLR)–induced changes in stroke volume index (SVI) in patients with atrial fibrillation after valvular heart surgery.Methods
In 43 patients with atrial fibrillation after cardiac surgery, PEEP was increased from 0 to 10 cm H2O for 5 min and changes in CVP were assessed. After returning the PEEP to 0 cm H2O, PLR was performed for 5 min and changes in SVI were recorded. Finally, 300 ml of colloid was infused and haemodynamic variables were assessed 5 min after completion of a fluid challenge. Fluid responsiveness was defined as an increase in SVI ≥10% measured by a pulmonary artery catheter.Results
Fifteen (35%) patients were fluid responders. There was no correlation between PEEP-induced increases in CVP and changes in SVI after a fluid challenge (β coefficient −0.052, P=0.740), whereas changes in SVI during PLR showed a significant correlation (β coefficient 0.713, P<0.001). The area under the receiver operating characteristic curve of the PEEP-induced increase in CVP and changes in SVI during PLR for fluid responsiveness was 0.556 [95% confidence interval (CI) 0.358–0.753, P=0.549) and 0.771 (95% CI 0.619–0.924, P=0.004), respectively.Conclusions
A PEEP-induced increase in CVP did not predict fluid responsiveness in patients with atrial fibrillation after cardiac surgery, but increases in SVI during PLR seem to be a valid predictor of fluid responsiveness in this subset of patients.