Does central venous oxygen saturation-directed fluid therapy affect postoperative morbidity after colorectal surgery?...

The optimal amount and method for monitoring intravenous fluid in surgical patients is unresolved. Central venous oxygen saturation (Scvo2) has been used to guide therapy and predict outcome in high-risk and intensive-care patients. The aim of this prospective, randomized trial was to compare the rate of postoperative complications in patients receiving fluid therapy guided by Scvo2 and those treated with a traditional effluent fluid scheme.

Patients undergoing open colorectal and lower intestinal surgery (n = 241) were randomized to the Scvo2 group or the control group. The Scvo2 group received perioperatively crystalloid infusion 100 ml/h. When Scvo2 was less than 75%, a bolus of 3 ml/kg hydroxyethyl starch was given. The bolus was repeated if Scvo2 increased by 1 percentage point or more. The control group was maintained with crystalloid 800 ml/h and given extra fluid if there were clinical signs of hypovolemia. The participating surgeon, unaware of the group allocation, registered complications within day 30.

Until 8:00 am on the first postoperative day, the Scvo2 group had received 3,869 ± 992 ml (mean ± SD) intravenous fluid compared with 6,491 ± 1,649 ml in the control group. Increase in weight was 0.8 ± 1.8 kg and 2.5 ± 1.6 kg in the two groups, respectively. The postoperative complication rate was 42% in both groups.

Clinical outcomes among patients receiving Scvo2-guided perioperative fluid therapy were similar to those for patients treated with a traditional fluid regimen. Limitations in study design prevent full interpretation of these findings, and further large trials of this treatment algorithm are still required.