Cerebral Oxygenation during Laparoscopic Surgery: Jugular Bulb versus Regional Cerebral Oxygen Saturation

PURPOSE: We hypothesized that regional cerebral oxygen saturation (rSO(2)) could replace jugular bulb oxygen saturation (SjvO(2)) in the steep Trendelenburg position under pneumoperitoneum. Therefore, we evaluated the relationship between SjvO(2) and rSO(2) during laparoscopic surgery. MATERIALS AND METHODS: After induction of anesthesia, mechanical ventilation was controlled to increase PaCO(2) from 35 to 45 mm Hg in the supine position, and the changes in SjvO(2) and rSO(2) were measured. Then, after establishment of pneumoperitoneum and Trendelenburg position, ventilation was controlled to maintain a PaCO(2) at 35 mm Hg and the CO(2) step and measurements were repeated. The changes in SjvO(2) (rSO(2)) -CO(2) reactivity were compared in the supine position and Trendelenburg-pneumoperitoneum condition, respectively. RESULTS: There was little correlation between SjvO(2) and rSO(2) in the supine position (concordance correlation coefficient=0.2819). Bland-Altman plots showed a mean bias of 8.4% with a limit of agreement of 21.6% and -4.7%. SjvO(2) and rSO(2) were not correlated during Trendelenburg-pneumoperitoneum condition (concordance correlation coefficient=0.3657). Bland-Altman plots showed a mean bias of 10.6% with a limit of agreement of 23.6% and -2.4%. The SjvO(2)-CO(2) reactivity was higher than rSO(2)-CO(2) reactivity in the supine position and Trendelenburg-pneumoperitoneum condition, respectively (0.9±1.1 vs. 0.4±1.2% mm Hg(-1), p=0.04; 1.7±1.3 vs. 0.5±1.1% mm Hg(-1), p<0.001). CONCLUSION: There is little correlation between SjvO(2) and rSO(2) in the supine position and Trendelenburg-pneumoperitoneum condition during laparoscopic surgery.