Effects of anesthetics on early postoperative cognitive outcome and intraoperative cerebral oxygen balance in patients undergoing lung surgery: a randomized clinical trial

Purpose One-lung ventilation (OLV) may impair cerebral oxygen balance and induce postoperative cognitive dysfunction (POCD). It is unclear whether the type of anesthetic influences the incidence of POCD in patients undergoing OLV. This prospective study compared the incidence of POCD and intraoperative cerebral oxygen desaturation in OLV patients anesthetized with propofol vs sevoflurane during lung surgery. Methods There were 148 participants enrolled in this study and randomized equally to either the propofol or the sevoflurane group. Anesthesia was maintained with either propofol or sevoflurane combined in both groups with fentanyl and epidural anesthesia. Regional cerebral oxygen saturation (rSO 2 ), jugular bulb venous oxygen saturation (SjO 2 ), and the incidence of cerebral oxygen desaturation (rSO 2 or SjO 2 < 50% or rSO 2 < 80% of baseline) were measured during anesthesia. Cognitive function was assessed using seven neurocognitive tests two days preoperatively, five days postoperatively (primary outcome), and three months postoperatively. Bivariable and multivariable regression analyses were conducted to identify factors associated with POCD. Results Rates of POCD did not differ statistically between groups five days postoperatively (propofol, 16/72 patients; sevoflurane, 24/72 patients; RR, 0.67; 95% CI, 0.39 to 1.15; P = 0.14) or three months postoperatively (propofol, 9/60 patients; sevoflurane, 12/58 patients; RR, 0.73; 95% CI, 0.33 to 1.59; P = 0.42). Only three subjects per group showed intraoperative cerebral oxygen desaturation. Multivariable regression analysis revealed older age as an independent predictor of POCD. Conclusions No statistically significant difference in the incidence of POCD could be detected between the sevoflurane and propofol anesthesia groups. Postoperative cognitive dysfunction was relatively frequent following OLV in both groups. (Registration number: UMIN 000002826).