星状神经节阻滞对家兔单肺通气期间氧合及肺内分流的影响

Effects of stellate ganglion block on intrapulmonary shunt and oxygenation during one-lung ventilation of rabbit

目的观察星状神经节阻滞(SGB)对单肺通气期间氧合及肺内分流的影响。方法健康成年大耳白兔在基础麻醉下暴露右侧星状神经节,置入并固定硬膜外导管。置管3 d后,选择24只随机分为两组:SGB组(n=12),在基础麻醉前10 min自硬膜外导管注射0.25%布比卡因0.5 mL;对照组(n=12),经导管注射生理盐水0.5mL。行气管切开插入气管导管控制呼吸,继而将导管插入右侧支气管行单肺通气。维持麻醉,连续监测心率(HR)、平均动脉压(MAP)、平均肺动脉压(MPAP)。分别于基础麻醉后(T0)、双肺通气15 min(T1)、单肺通气15min(T2)、30 min(T3)、60 min(T4)、120 min(T5)、恢复双肺通气30 min(T6)时抽取动脉血和混合静脉血血样测定血气,通过公式计算肺内分流量(Qs/Qt)和全身氧合情况。结果两组家兔术前单肺通气后肺内分流均增加(P<0.05),Qs/Qt在T3、T4时对照组高于SGB组(P均<0.05)。单肺通气期间两组PaO2较双肺通气时均明显下降(P均<0.05),T3时点降至最低,之后逐渐回升;T2、T3、T4时点对照组较SGB组PaO2显著降低(P均<0.05)。全麻机械通气使MPAP上升(P<0.05),T3、T4时点对照组较SGB组MPAP升高明显(P均<0.05)。结论星状神经节阻滞不明显增加同侧单肺通气期间的肺内分流,有利于改善单肺期间的氧合,减少术中低氧血症的发生。

Objective To observe the effects of stellate ganglion block on oxygenation and intrapulmonary shunt dur -ing one-lung ventilation （ OLV） of rabbit .Methods Healthy adult rabbits were exposed right stellate ganglion under basal anesthesia , an epidural catheter was placed and fixed .3 days later , twenty-four healthy rabbits were randomly divided into 2 groups：SGB group （n=12）, 0.25%bupivacaine 0.5 mL was injected through the epidural catheter 10 min before basal anesthesia;control group （n=12）, physiological saline 0.5 mL was injected through the epidural catheter .Inserting an endotracheal tube to control breathing after a tracheotomy performed , then the tube was inserted into the right bronchus un-derwent one lung ventilation .To maintain anesthesia , ECG, MAP, MPAP were continuously monitored during anesthesia . Blood samples were taken from radial artery and mixed venous blood for blood gas analysis at following intervals ：the rabbit was basal anesthesia （T0）, 15 min after two lung ventilation （T1）, 15, 30, 60, 120 min during the course of one lung ventilation （ T2 , T3 , T4 , T5 ） and the two lungs ventilation again for 30 min （ T6 ） .Calculation of pulmonary and systemic oxygenation by formula .Results Qs/Qt was significantly increased after OLV was started , there were significant differ-ence in Qs/Qt at T3, T4 points between two groups （all P〈0.05）.PaO2 was significantly lower after OLV and reached the lowest level at T3 then was gradually increasing , which were significant difference in PaO 2 at T2 , T3 , T4 points between two groups （all P〈0.05）.MPAP in control group increased significantly at T 3, T4 compared with group SGB （P〈0.05）. Conclusion During OLV, general anesthesia combined SGB does not affect Qs /Qt and provide higher PaO 2 than general anesthesia , and decrease the incidence rate of hyoxemia during operation .