右美托咪定对单肺通气患者血流动力学及肺内分流率的影响

Effects of dexmedetomidine on haemodynamics and intra-pulmonary shunt rate in patients undergoing one-lung ventilation

目的探讨右美托咪定对行单肺通气患者血流动力学及肺内分流率(Qs/Qt)的影响。方法全凭静脉麻醉下行择期胸腔镜下肺叶切除术患者60例随机分为两组,每组30例。D组在麻醉诱导前10 min静脉注射右美托咪定0.5μg/kg,然后连续输注右美托咪定0.5μg·kg^-1·h^-1;C组注射等容量生理盐水作为对照。记录气管插管前(T0)、双肺通气10 min(T1)、单肺通气15 min(T2)和30 min(T3)4个时间点的血流动力学指标和血气分析结果,计算Qs/Qt。结果 D组在T1~T3时的SBP和DBP低于C组(P<0.05)。与T1时比较,C组在T2和T3时的心输出量(CO)、心脏指数(CI)、每搏输出量(SV)和每搏输出量指数(SVI)均升高(P<0.05);D组T2和T3时的CO、CI、SV和SVI低于C组(P<0.05)。与T0时相比,两组T1~T3时Qs/Qt均增加(P<0.05);且两组T2、T3时的Qs/Qt大于T1时(P<0.05)。D组T2、T3时的Qs/Qt低于C组(P<0.05)。D组术中丙泊酚和芬太尼总用量少于C组(P<0.05)。结论全凭静脉麻醉期输注右美托咪定能减少胸腔镜下肺叶切除术患者麻醉药物用量,降低单肺通气期的Qs/Qt,较好地维持氧合功能和血流动力学稳定。

Objective To investigate the effects of dexmedetomidine on the haemodynamics and intra-pulmonary shunt rate(Qs/Qt) in the patients undergoing one-lung ventilation(OLV).Methods Sixty patients undergoing elective thoracic operation under total intravenous anesthesia were randomly divided into two groups with 30 cases each.The patients in group D received 0.5 μg/kg of dexmedetomidine intravenously within 10 minutes before anesthesia induction,which was followed by 0.5 μg·kg^-1·h^-1 of dexmedetomidine infusion.The patients in group C were infused normal saline as the controls.At the time points of T0(before intubation),T1(double-lung ventilation for 10 minutes),T2(OLV for 15 minutes) and T3(OLV for 30 minutes),the haemodynamic parameters were detected,the gas analysis results were recorded,and the Qs/Qt was calculated.Results The SBP and DBP at T1-T3 were lower in group D than those in group C(P<0.05).At T2 and T3,the cardiac output(CO),cardiac index(CI),stroke volume(SV) and stroke volume index(SVI) in group C were higher than those at T1 and those in group D(P<0.05).The Qs/Qt at T1-T3 was higher than that at T0 in both groups(P<0.05),which at T2 and T3 was higher than that at T1 in both groups(P<0.05).The Qs/Qt at T2 and T3 was lower in group D than that in group C(P<0.05).The total consumptions of propofol and fentanyl were less in group D than those in group C during operation(P<0.05).Conclusion Dexmedetomidine infusion during total intravenous anesthesia can decrease the consumptions of anesthetic agents,reduce the Qs/Qt during OLV,and maintain better oxygenation function and stable hemodynamics in the patients undergoing thoracic surgery.