Li Z, Li H, Yao S, Cheng M, Chen J
Shantou University Medical College, Shantou 515000, China.
Department of Anesthesiology, Second People's Hospital of Futian District, Shenzhen 518000, China.
Nan Fang Yi Ke Da Xue Xue Bao. 2021 Apr 20;41(4):600-606. doi: 10.12122/j.issn.1673-4254.2021.04.18.
To explore the immunomodulatory mechanism and optimal dose of dexmedetomidine (DEX) for preventing postoperative cognitive dysfunction (POCD) in elderly patients undergoing spinal surgery.
A total of 120 elderly patients undergoing elective spinal surgery with general anesthesia were randomized into 4 groups to receive a loading dose of 0.3 μg/kg DEX for 10 min before anesthesia induction followed by maintenance doses of 0.2, 0.5, and 0.8 μg · kg·h (low-, medium-, and high-dose DEX groups, respectively) or an equal volume of normal saline (control group). DEX and saline was discontinued 40 min before the end of the surgery. Before induction (D) and on day 1 (D), day 3 (D) and day 7 (D) after the operation, the cognitive function of the patients was assessed using the MMSE scale and their serum levels of β-amyloid (Aβ), TNF-α, IL-1β and IL-6 were measured. The occurrence of adverse effects including bradycardia and hypotension and the recovery time of the patients were recorded.
Compared with those on D, serum levels of Aβ, IL-1β, IL-6, and TNF-α on D were markedly increased in all the groups ( < 0.05); the levels of Aβ decreased to the baseline level on D in medium- and high-dose DEX groups ( > 0.05) but remained high in the other two groups. On D, TNF-α, L-1β and IL-6 recovered their baseline levels in medium- and high-dose DEX groups ( > 0.05) but remained elevated in the other two groups. The incidences of POCD in medium- and high-dose DEX groups were comparable but significantly lower than that in the control group ( < 0.05). The incidences of hypotension and bradycardia were the highest in high-dose DEX group ( < 0.01), which also had longer recovery time than the other 3 groups ( < 0.05).
With a loading dose of 0.3 μg/kg followed by a maintenance doses of 0.5 μg · kg·h, DEX can effectively reduce the incidence of POCD in elderly patients undergoing spinal surgery by inhibiting the production of Aβ and pro-inflammatory cytokines.
探讨右美托咪定（DEX）预防老年脊柱手术患者术后认知功能障碍（POCD）的免疫调节机制及最佳剂量。
将120例行择期脊柱手术的老年患者随机分为4组，在麻醉诱导前10分钟静脉注射负荷剂量0.3μg/kg DEX，随后分别给予维持剂量0.2、0.5和0.8μg·kg·h（分别为低、中、高剂量DEX组）或等体积生理盐水（对照组）。手术结束前40分钟停用DEX和生理盐水。在诱导前（D0）、术后第1天（D1）、第3天（D3）和第7天（D7），采用简易精神状态检查表（MMSE）评估患者的认知功能，并检测其血清β-淀粉样蛋白（Aβ）、肿瘤坏死因子-α（TNF-α）、白细胞介素-1β（IL-1β）和白细胞介素-6（IL-6）水平。记录包括心动过缓和低血压在内的不良反应发生率及患者的恢复时间。
与D0时相比，各组D1时血清Aβ、IL-1β、IL-6和TNF-α水平均显著升高（P<0.05）；中、高剂量DEX组D3时Aβ水平降至基线水平（P>0.05），而其他两组仍维持在较高水平。中、高剂量DEX组D3时TNF-α、IL-1β和IL-6恢复至基线水平（P>0.05），而其他两组仍维持在较高水平。中、高剂量DEX组POCD发生率相当，但均显著低于对照组（P<0.05）。高剂量DEX组低血压和心动过缓发生率最高（P<0.01），其恢复时间也长于其他3组（P<0.05）。
负荷剂量0.3μg/kg，随后维持剂量0.5μg·kg·h，DEX可通过抑制Aβ和促炎细胞因子的产生有效降低老年脊柱手术患者POCD的发生率。
