Conservative vs restrictive individualized goal-directed fluid replacement strategy in major abdominal surgery: A prospective randomized trial.

OBJECTIVES To compare the influence of 2 volumes of fluid, integrated with goal-directed fluid therapy, on hypovolemia (a key trigger of tissue hypoperfusion) and central venous oxygen saturation (Scvo₂) and to assess their relationships with postoperative morbidity. DESIGN, SETTING, AND PATIENTS A prospective, randomized trial of 70 consecutive patients undergoing major abdominal surgery. INTERVENTIONS Patients were randomly assigned to 6 mL/kg/h of crystalloid (a restrictive fluid strategy) or 12 mL/kg/h of crystalloid (a more conservative fluid strategy). In both groups, a fluid bolus was administered when respiratory variation in peak aortic flow velocity (ΔPV) was greater than 13%. Data on hypovolemia (ΔPV > 13%), Scvo₂, and postoperative complications were recorded for all patients. MAIN OUTCOME MEASURES Overall incidence of postoperative complications, especially anastomotic leak and sepsis. RESULTS Overall incidence of complications, including postoperative anastomotic leak and sepsis, was higher in the restrictive group than in the conservative group (all P < .05). The number of patients with hypovolemia increased significantly in the restrictive group compared with the conservative group (P < .001). The perioperative mean Scvo₂ (P = .02) and mean minimum Scvo₂ (P = .04) were significantly lower in the restrictive group than in the conservative group. Multivariate analysis showed that both hypovolemia and mean minimum Scvo₂ were independently associated with anastomotic leak and sepsis. CONCLUSIONS Excessive fluid restriction increased the level of hypovolemia, leading to reduced Scvo₂ and thereby increased incidence of postoperative complications. Excessive fluid restriction should be applied cautiously in surgical patients. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00852449.