Abstract: Objective To observe whether dexmedetomidine can increase the level of analgesia and sedation during cesarean section(C-section) in elderly parturients with gestational hypertension, maintain hemodynamics stability, reduce perioperative inflammatory response and oxidative stress injury. 
Methods A total of 60 cases of elderly parturients with gestational hypertension who underwent C-section were selected and divided into dexmedetomidine group(group D) and control group(group C), with 30 cases in each group. Group D was given dexmedetomidine hydrochloride(the loading amount was 0.5 μg/kg, and the maintenance rate was 0.2 μg·kg-1·h-1until the end of operation) after the fetus was delivered and the umbilical vein was cut, and the constant volume of normal saline was given to group C in the same manner. After surgery, the intravenous self-controlled analgesia pump was connected, group D was given dexmedetomidine 2 μg/kg+sufentanil 2 μg/kg+ dezocine 0.3 mg/kg+tropisetron 10 mg+saline 100 mL, while group C was given sufentanil 2 μg/kg+dezocine 0.3 mg/kg+tropisetron 10 mg+saline 100 mL. The following indexes were collected: ①Ramsay sedation score and visual analogue scale(VAS) before surgery(T1), at 20 min after administration(T2) and immediately after surgery(T3), at 6 h(T4), 24 h(T5) and 48 h(T6) after surgery as well as additional times of postoperative analgesia pump; ②Hemodynamic parameters at T1-T6; ③Incidence of adverse reactions; ④Indicators of inflammatory response and oxidative stress: tumor necrosis factor-α(TNF-α), interleukin 6(IL-6), malondialdehyde(MDA) and superoxide dismutase(SOD) in venous blood at T1-T6. 
Results Ramsay sedation score at T2-T6 in group D was significantly higher than that in group C, VAS pain score at T4-T6 in group D was significantly lower than that in group C(P＜0.05). Additional times of postoperative analgesia pump in group D was significantly lower than that in group C(P＜0.05). The levels of SBP, DBP and HR in group D at T2-T6 were significantly lower than those in group C(P＜0.05). There was no significant difference in the incidence of adverse reactions between the two groups(P＞0.05). At T2-T6, the levels of TNF-α, IL-6 and MDA in group D were significantly lower than those in group C, and the levels of SOD were significantly higher than those in group C(P＜0.05). 
Conclusion Dexmedetomidine can maintain the stability of perioperative hemodynamics in elderly parturients with gestational hypertension, alleviate anxiety and pain, and reduce inflammatory response and oxidative stress response through analgesia and sedation, thus improving the prognosis. 

Key words: hypertension, pregnancy-induced, dexmedetomidine, inflammation