On The Impact Of Sevoflurane On Postoperative Cognitive Function In Long-term Studies

Objective:This study was designed to assess whether at 1 month and 6 months postoperatively, the cognitive function of children receiving strabismus surgery with sevoflurane anaesthesia was declined as compared with 1 day preoperatively.Methods:60 children undergoing elective strabismus surgery with general anaesthesia, were enrolled in this study. Anaesthesia was induced by inhalation of 8% sevoflurane, the fresh oxygen flow (FiO2=100%)was set at 8 liter min-1. After loss of awareness, the patients were inserted canula in their vein, received atropine 0.01mg/kg, fentanyl 3-4μg/kg and rocuronium 0.4mg/kg. Then we inserted LMA in the right position. And the concentration of sevoflurane was reduced to 3%, fresh oxygen flow and FiO2 was adjusted to 2 liter min-1, and 50%. Minimum alveolar concentration(MAC) was set at 1.2(between 1.1 and 1.5). We used pressure control ventilation mode (Paw was set at 8-12 cmH20, frequency was set at 12-20/min, and the ratio of inspiratory and expiratory was 1:2, no end-expiratory positive pressure was applied). The anaesthesia machine was adjusted so as to keep PETCO2 between 35 and 45 mmHg. Once the surgery was completed, inhalation of sevoflurane ceased, the children were given midazolum 20μg/kg, ramosetron hydrochlorid 5μg/kg and sent to post-anaesthetic care unit(PACU) with the LMA inserted. The mood preoperatively, anaesthetic duration, whether the hypoxia happened, postoperative agitation was recorded. The Wechsler Preschool and Primary Scale of Intelligence(WPPSI) was measured at 1 day preoperatively(T1), 1 month postoperatively (T2) and 6 months postoperatively(T3).Result:40 among the 60 children accomplished the study in the end. The scores of animal pegs, block design, performance intelligence quotient (PIQ), full intelligence quotient (FIQ) were significantly higher at 1 month postoperatively than 1 day preoperatively, no significant difference was found in other aspects. The scores of vocabulary, arithmetic, comprehension, maze, geometric design were not significantly different between group(T1) and group(T3). While the scores of informations, similarities, verbal IQ, animal pegs, picture completion, block design, PIQ and FIQ were significantly higher at 6 months postoperatively than 1 day preoperatively.Conclusions:This study may preliminarily show that general anaesthesia with sevoflurane does no obviously harm to the middle and long term cognitive function of the preschool and primary postoperatively.