Background: Combined monitoring of blood flow with assessment of fluid status and cerebral tissue oxygenation improve perioperative management and outcome of high-risk surgical patients. The study tests if intraoperative multimodal monitoring reduces postoperative morbidity and duration of hospitalisation in patients undergoing major abdominal surgery managed by same anaesthetic protocols with epidural analgesia.Methods: Prospective study was conducted in 2 parallel groups. High risk surgical patients undergoing major abdominal surgery were randomised in control group (CG), where standard monitoring was applied and protocol group (PG), where cerebral oxygenation and haemodynamic monitoring were used with protocol for intraoperative interventions.Results: There was no difference in median length of hospital stay, CG 9 days (IQR 8 days), PG 9 (5.5), p= 0.851. There was no difference in postoperative renal of cardiac impairment. Procalcitonin was significantly higher (highest postoperative value in first 3 days) in CG, 0.75 mcg/L (IQR 3.19mcg/L), than in PG 0.3 mcg/L (0.88 mcg/L), p= 0.001. Patents in PG received larger intraoperative amount of fluids; median intraoperative fluid balance +1300 ml (IQR 1063ml) than CG; +375 ml (IQR 438ml), p<0.00.Conclusions: There was no difference in postoperative morbidity or hospital stay. Median postoperative value of procalcitonin was significantly higher in CG and was above laboratory reference range. There were significant differences in intraoperative fluid management.Trial registration: ClinicalTrials.gov, NCT02293473, Registered June 10, 2014, https://clinicaltrials.gov/