Automated pulse pressure and stroke volume variations from radial artery: evaluation during major abdominal surgery

Off-line calculation of the pulse pressure variation (PPVref) has repeatedly been shown to be a reliable predictor of fluid responsiveness in mechanically ventilated patients. This study was designed to assess the ability of two algorithms for automated calculation of PPV (PPVauto) (Intellivue MP 70) and stroke volume variation (SVVauto) (FloTrac/Vigileo) to predict fluid responsiveness during abdominal surgery. We conducted a prospective study of 56 fluid challenges given for haemodynamic instability in 11 patients undergoing major abdominal surgery. Fluid responsiveness was defined as an increase in stroke volume index (SVI) >10%. PPVref, PPVauto, SVVauto, and SVI (oesophageal Doppler) were recorded simultaneously before and after each fluid challenge. PPVauto and SVVauto both correlated with PPVref [rcorr=0.87 (P