Abstract： Objective:To investigate the impact of concurrent high-altitude osteoporotic femoral fracture and high-altitude de-acclimatization syndrome（HADAS）on intraoperative hemodynamics，cerebral neurologic function，and cognitive function in patients undergoing general anesthesia.Methods:Among the patients underwent operation under general anesthesia in the Department of Orthopedics of Chengdu Office Hospital of the People’s Government of Tibet Autonomous Region from March 2019 to March 2021，69 patients with concurrent high-altitude osteoporotic femoral fracture and HADAS（HADAS group）and 63 patients with simple high-altitude osteoporotic femoral fracture（control group）were selected as the research subjects. Intraoperative hemodynamic indexes of the two groups were recorded，such as heart rate（HR），mean artery pressure（MAP），and pulse oxygen saturation（SpO 2）. Cerebral neurological function indexes，such as S100 protein（S100 β），myelin basic protein（MBP），and neuron-specific enolase（NSE）were detected by radioimmunoassay. Inflammation-related indexes，such as interleukin（IL）-2，IL-4，IL-13，and interferon-gamma（IFN-γ）were detected by enzyme-linked immunosorbent assay（ELISA）. Cognitive function was evaluated with the mini mental state examination（MMSE）scale and the Montreal cognitive assessment（MoCA）scale. Results:The HR，MAP，and SpO 2 of the two groups at T1（5 min after tracheal intubation）were lower than those at T0，respectively；those indexes at T2（after operation）were high than those at T1；the HR，MAP，and SpO 2 of the HADAS group at T1 and T2 were lower than those of the control group，at the corresponding time points（all P<0.05）. After operation，the S100β，MBP，NSE，IL-4，and IL-13 in both groups were higher than those before operation，while IL-2 and INF-γ in the two groups were lower than those before operation（all P<0.05）；S100β，MBP，NSE，IL-4，and IL-13 in the HADAS group were significantly higher than those in the control group，while IL-2 and INF-γ in the HADAS group were significantly lower than those in the control group（all P<0.001）. On one day after operation（both P<0.001），MMSE scores and MoCA scores of the two groups were significantly lower than those before operation（both P<0.05），and the HADAS group had lower scores than the control group（both P<0.001）. Conclusion:Compared with the high-altitude osteoporotic femoral fracture patients without HADAS，the high-altitude osteoporotic femoral fracture patients with HADAS have worse cognitive function，hemodynamics，and cerebral neurological function in the immediate postoperative period after general anesthesia. Therefore，cautious selection of anesthesia is needed for the patients with HADAS.