Olanzapine attenuates postoperative cognitive dysfunction in adult rats

Abstract

Background: Postoperative cognitive dysfunction (POCD) is associated with poor quality of life and difficulty working. Its impact may be greater in middle-aged patients than in elderly patients. Neuroinflammation is reported to be a main cause of POCD. Olanzapine has been reported to improve learning and memory functions. We therefore investigated olanzapine's effectiveness and mechanisms in an adult rat POCD model. Methods: Six-month-old rats underwent laparotomy and lipopolysaccharide (LPS group) or LPS þ olanzapine (OLA group) intraperitoneal injection or anesthesia alone (CON group) 1 week after a Barnes maze training session. A Barnes maze test trial was then conducted the day after surgery or anesthesia. The microglial activity in the hippocampus and cytokine levels were measured by Iba1 staining and enzyme-linked immunosorbent assay, respectively. Results: The OLA group had significantly higher success rates of Barnes maze trial than the LPS group. The success rate in time of the OLA group was inferior to that of the CON group. On the other hand, the success rate in distance of the OLA group was similar to that of the CON group. Iba1 staining areas in the LPS and OLA groups were larger than that in the CON group; however, the staining area in the OLA group was smaller than that of the LPS group. Plasma interleukin-1β concentration in the LPS and OLA groups was significantly higher than that in the CON group; however, there was no significant difference between the LPS and OLA groups. Conclusion: Olanzapine attenuated both spatial cognitive dysfunction and microglial activity of the hippocampus, which were induced by surgery and LPS injection. These effects were unrelated to inflammatory cytokine concentrations in plasma and hippocampus.

Postoperative delirium in geriatric patients with hip fractures

“…However, two massive prospective RCTs that compared haloperidol to ketamine or ziprasidone respectively, indicated that none of the three medications could shorten the frequency and duration of postoperative cognitive dysfunction and POD in patients with a critical illness ( Girard et al, 2018 ; Hollinger et al, 2021 ). Some studies supported the efficacy of SGAs such as aripiprazole, risperidone, and olanzapine in the treatment of POD; nevertheless, the quality of the evidence is poor because of the heterogeneity and bias of the research ( Tachi et al, 2021 ; Sugawara et al, 2022 ). Moreover, the safety of antipsychotics is more concerning than their efficacy.…”