The purpose of this study is to determine whether intraoperative goal-directed fluid management (with goal = cardiac stroke volume maximization) based on respiratory-induced pulse pressure variation monitoring may improve outcome after intrabdominal surgery

Recent studies strongly suggest that intraoperative oesophageal doppler guided fluid management may improve outcome after intrabdominal surgery. In these studies, however, the number of patients was often small, and management in control groups as well as postoperative complications were usually not precisely defined. In addition, widespread use of oesophageal doppler cannot be advocated in routine surgery, and the strategy necessitates repeated volume loading. This may lead to unnecessary intravenous fluids which may be deleterious, and intraoperative fluid restriction has also been shown to improve clinical outcome. In this context, indices reflecting the hemodynamic changes during mechanical ventilation (the so-called "dynamic indices", and more specifically the respiratory-induced pulse pressure variation) have been shown to accurately predict fluid responsiveness in mechanically ventilated patients. Automated and continuous calculation of pulse pressure variation variation from standard peripheral (typically radial) arterial line has recently been validated. This study was thus designed to determine whether intraoperative goal-directed fluid management (with goal = cardiac stroke volume maximization) based on pulse pressure variation monitoring would improve outcome after intrabdominal surgery.

Inclusion Criteria:

• major elective intrabdominal surgery

Exclusion Criteria:

• arrhythmia
• hepatectomy
• associated thoracic surgery
• laparoscopy
• pregnancy
• allergy to colloid solution or anesthesia protocol
• arterial catheter not possible