Effects of dexmedetomidine on hemodynamics and extubation during recovery period from general anesthesia in elderly patients

Objective To explore the effects of preoperative application of dexmedetomidine(DEX)on the hemodynamics and extubation during recovery period from general anesthesia in elderly patients.MethodsSixty patients(aged 60-85 years,weighing 50-85 kg,American Society of Anesthesiologists class Ⅱ orⅢ)undergoing elective hip-fracture operation under general anesthesia were randomly divided into DEX group and control group(n=30).DEX(0.5μg/kg)and normal saline were injected,in the two groups by venous pump for15 min before surgery respectively.Mean arterial pressure(MAP)and heart rate(HR)were recorded before drug infusion(T0),at 10 min after drug infusion(T1),at the end of drug infusion(T2),immediately after intubation(T3),at the time of skin-cutting(T4),at 30 min of surgery(T5),at the end of surgery(T6),at 5min(T7)and30min after extubation(T8).The time and bispectral index score(BIS)were also recorded at spontaneous respiration recovery,eyes-opening on verbal command and extubation.Results In the DEX group,MAP and HR at T4,T5 and T6 were significantly lower than those at T0(all P0.05).In the control group,MAP and HR at T3 were significantly higher than those at T0(both P0.05),while MAP and HR at T4,T5 and T6 were significantly lower than those at T0(all P0.05).MAP and HR at T3 and T7and HR at T4 in the control group were significantly higher than those in the DEX group(all P0.05).The BIS in the DEX group was significantly higher than that in the control group when autonomous breathing recovered(P0.05).The total consumption of propofol and fentanil in the DEX group were significantly lower than those in the control group(both P 0.05).There were no significant differences in terms of spontaneous respiration recovery time,eyes-opening on verbal command time or BIS,extubation time or BIS between two groups(all P0.05).Neither was the incidence of bradycardia nor hypotension(both P 0.05).Conclusion Application of 0.5μg/kg dexmedetomidine in elderly patients undergoing hip operation can make perioperative hemodynamics more stable,and does not affect the awakening and extubation.