Objective  To investigate the effect of cerebral oxygen saturation (rSO₂) on postoperative cognitive dysfunction (POCD) and S-100β protein in children after laparoscopic surgery at high altitude.

  Methods  A total of 68 children who underwent elective laparoscopic surgery at Shigatse People's Hospital (3850 m above sea level) were selected as research subjects. They were divided into study group (n=34) and control group (n=34). Children in both groups underwent general anesthesia before the operation, the control group underwent total intravenous anesthesia, the study group underwent tracheal intubation anesthesia. Near-infrared spectroscopy was used to continuously monitor level of rSO₂. The levels of rSO₂ of the two groups were recorded at the time points of entering the room (T₀), after mask oxygen inhalation (T₁), before establishment of pneumoperitoneum (T₂), and after 30 minutes of pneumoperitoneum (T₃), and the end of pneumoperitoneum (T₄). The cognitive function changes before operation, 1 day and 3 days after operation were evaluated and recorded by Mini-mental State Examination (MMSE), the changes of S-100 β protein levels before operation, 1 day after operation and 3 days after operation and the incidence of POCD were compared between the two groups.

  Results  The levels of rSO₂ of the two groups were higher at T₄ than those of the T₀, T₁, T₂ and T₃ (P < 0.05), were higher at T₃ in both groups than those at T₀, T₁ and T₂ (P < 0.05), and were higher at T₂ in both groups than those of T₀ (P < 0.05). The MMSE scores of the two groups at 1, 3 d were lower than those before operation (P < 0.05). The scores of MMSE after 3, 7 d of operation were higher than that of 1 day of operation, and the scores of MMSE at 7 d in both groups were higher than those at 3 d (P < 0.05). There was no significant difference between 7 d MMSE score and preoperative MMSE score in the two groups (P>0.05). The S-100 β protein levels in the two groups at different time points of 1 and 3 d were significantly higher than preoperation, were lower at 3, 7 d than at 1 d after operation (P < 0.05). There was no significant difference in S-100β protein level between 7 days after operation and preoperation(P>0.05). The incidence of POCD was 8.82% in the study group and 5.88% in the control group, there was no significant difference in the incidence of POCD between the two groups (P>0.05).

  Conclusion  Monitoring and regulating rSO₂ during laparoscopic operation in children in highland area can reduce the occurrence of POCD, and effectively reduce the serum S-100β protein level 3 days after operation. Regardless of applition of intravenous anesthesia or endotracheal intubation anesthesia, it has a brain protective effect.