Volume Optimisation and Cognitive Function in Major Abdominal Surgery

In the last 25 years, there has been a lot of attention directed on reducing perioperative morbidity and mortality by improving intraoperative monitoring and hemodynamic optimisation of patients. Advanced monitoring devices and new parameters have shifted the focus of anaesthesia management from macro- to micro circulation with the emphasis on the determinants of oxygen delivery and tissue oxygenation. There is increasing evidence that long-term outcome is improved by goal-directed optimisation of hemodynamic parameters (optimisation of stroke volume and cardiac output by fluids and inotropic and vasoactive drugs). Besides, new monitoring possibilities (depth of anaesthesia and cerebral and tissue oxygenation monitors) and adherence to protocols have proved beneficial in reducing morbidity cognitive dysfunction. However, questions are raised what the optimal goals (healthy population derived normal values, preoperative values, maximal values, restrictive fluid management) should be. Secondly, all new methods were used separately and there is a lack of studies to show the effect of combined (multimodal) monitoring on occurrence of cognitive dysfunction. All gathered data indicate that the combined use of new methods with adherence to an appropriate protocol might radically improve the perioperative management and outcome of high-risk surgical patients. The present study tests the hypothesis that intraoperative multimodal monitoring with hemodynamic optimisation, BIS-guided anaesthesia and maintenance of optimal cerebral oxygen saturation will reduce cognitive dysfunction.