Effect of Anesthesia and Surgery on Postoperative Spatial Working Memory

Objective To investigate the differences of postoperative spatial working memory following sevo-flurane or propofol anesthesia alone and their combination with surgeries respectively in young rats.Methods After 5-day training in Morris water maze, 46 healthy male SD rats were randomly assigned to 5 groups: propofol group(group P), sevoflurane group(group S), propofol plus surgery group(group PS), sevoflurane plus surgerygroup(group SS), control group(group C). The rats of group P were induced by intravenous injection of 15 mg/kgpropofol, and anesthesia was maintained with 50 mg/(kg·h) propofol for 2 hours. 4% sevoflurane was inhaled forinducing anesthesia, and then the inhaled concentration of sevoflurane was decreased to 2% and maintained for 2 hours in group S. The rats of group C inhaled the mixture of air/oxygen(fraction of inspired oxygen, 30%) for 2 hours. The surgery was exploratory laparotomy. The spatial working memory was assessed 24 h after regainingconsciousness using Morris water maze.Results The percentage of target quadrant time was 27.88 ± 9.00%,29.22±8.28%, 28.33±5.27%, 28.17±4.22%, 24.79±3.43% respectively in group P, group S, group PS, group SSand group C. Compared with group C, the percentages of target quadrant time were not significantly declined ingroup P, group S, group PS and group SS(P 0.05), and there were no significant differences neither betweengroup P and group PS nor between group S and group SS in day1 after regaining consciousness(P 0.05). Compared with group C,the spatial working memory was not significantly impaired in group P, group S, group PS,group SS respectively in day 7 and day30 after regaining consciousness(P 0.05), and there were no significantdifferences neither between group P and group PS nor between group S and group SS(P 0.05).Conclusion Anesthesia with propofol or sevoflurane alone and their combination with minor abdominal surgery respectively did not result in impaired long-term spatial working memory in the young rats assessed by Morris water maze.