Central venous oxygen saturation does not correlate with the venous oxygen saturation at the surgical site during abdominal surgery

Abstract

Introduction: Measurement of central venous oxygen saturation has become a surrogate parameter for fluid administration, blood transfusions and treatment with catecholamines in (early) goal directed therapy in the treatment of acute septic patients. These strategies are not easily transferred to the postoperative management of abdominal surgery due to the different conditions in surgical patients.Materials and methods: A study population of 15 patients (8 females/7 males) underwent elective major abdominal surgery: 6 gastrectomies, 5 major liver resections and 4 lower anterior rectum resections. Surgery was performed for primary or secondary malignancy. The patients' age was 65.4 ± 12.7 (mean ± standard deviation, range 44-84, median 62) years. Blood samples were taken intraoperatively from indwelling central venous lines as well as from draining veins at the surgical site. Blood gas analyses to determine the oxygen saturations were performed immediately. All patients were operated in standardized general anesthesia including epidural analgesia and in a balanced volume status.Results: Central venous oxygen saturations and oxygen saturations in blood from the draining veins of the surgical site showed a wide range with high intra-and interindividual differences intraoperatively. Overall, at most time points no correlation between the two oxygen saturations could be detected in three operation types. A significant correlation was only observed at one time point during liver resections.Conclusion: Our results show a lack of correlation between central venous oxygen saturations and oxygen saturations in the draining veins of the surgical site during major abdominal surgery. Measurement of central venous oxygen saturations does not seem to be a good surrogate for the local oxygen supply in the field of interest in major abdominal surgery even under standardized conditions.

Effect of changes in inspired oxygen fraction on oxygen delivery during cardiac surgery: a substudy of the CARROT trial

“…First, there is growing concern about the harmful effects of hyperoxia caused by high FiO 2 , although most previous clinical studies failed to demonstrate significantly poorer clinical outcomes due to hyperoxia or high FiO 2 16 , 17 . Second, DO 2 can increase in response to transfusion or intravascular volume expansion, but we do not know whether achieving the same level of SvO 2 with different modalities results in an equivalent distribution of oxygen to the organs; the distribution of oxygen supply and demand differs among organs 18 . Weinrich et al failed to find a correlation between surgical site oxygen saturation and central venous oxygen saturation in patients undergoing major non-cardiac surgery 19 .…”