Effects of pretreatment with dexmedetomidine on hemodynamics during laparoscopic cholecystectomy surgery

Objective To observe the effects of intravenous pretreatment with different doses of dexmedetomidine hydrochloride injection(Dex) on hemodynamics during laparoscopic cholecystectomy surgery.Methods Seventy six patients at American Society of Anesthesiologists(ASA) physical status Ⅰ— Ⅱ for laparoscopic cholecystectomy surgery were randomly divided into four groups(n = 19 in each group) : control group(group C,infusion of normal saline before induction of anesthesia),low-dose group(group L,infusion of Dex at the dose of 0.6 μg / kg),middle-dose group(group M,infusion of Dex at the dose of 0.8 μg / kg) and high-dose group(group H,infusion of Dex at the dose of 1.0 μg / kg).Systolic blood pressure(SBP),diastolic blood pressure(DBP) and heart rate(HR) were recorded the time before infusion of dexmedetomidine(T 0),10 minutes after infusion of dexmedetomidine(T 1),the time of intubation(T 2),1 minute after intubation(T 3),10 minutes after pneumoperitoneum(T 4) and the time of extubation(T 5).Results Compared with T 0,HR was significantly decreased at T 1 in group M and H,SBP and DBP were significantly increased at T 1 in group H(P 0.05).Compared with T 1,blood pressure(BP) and HR were significantly lower at T 2,while higher at T 3-T 5 in group C and L(P 0.05).BP at T 1-T 5 was significantly higher in group H than in group M(P 0.05).Conclusion When the dose of dexmedetomidine reaches 0.8 μg / kg,it may effectively inhibit the stress reaction at intubation and CO 2 pneumoperitoneum,and thus stabilize hemodynamia.