右美托咪定对食管癌根治术患者单肺通气时肺内分流及动脉氧分压的影响

Effects of dexmedetomidine on intrapulmonary shunt and oxygen pressure of the artery during one-lung ventilation undergoing esophageal cancer resection

目的观察右美托咪定（Dex）对食管癌手术中单肺通气（OLV）肺内分流和动脉氧分压（PaO：）的影响。方法40例择期行左经胸食管癌根治术患者，美国麻醉医师协会（ASA）分级I～Ⅱ级，年龄25-65（57．2±8．5）岁，术前检查心肺功能良好，随机分为2组（每组20例）：Dex组和生理盐水（Ns）组，Dex组麻醉诱导给予Dex负荷量0．6μg／kg，给药时间10min，0．4μg／（kg·h）维持至手术结束前30min；NS组：给于等量生理盐水泵注。采集麻醉诱导后侧卧位双肺通气30min（T1）、OLV30min（T2）、OLV60min（T3）、OLV90min（T4）、恢复双肺通气（TLV）30min（T5）时桡动脉和颈内静脉血进行血气分析，根据血气值计算肺内分流率（Qs／Qt），记录PaO2值。结果两组血流动力学指标平均动脉压（MAP）和脑电双频指数（BIS）比较差异无统计学意义（P〉0．05）。与T1时比，两组T2-4时PaO2显著降低，Qs／Qt显著升高（P〈0．05）；与T1时比，Ns组t5时PaO2显著降低，Qs／Qt显著升高（P〈0．05），Dex组T5时PaO2和Qs／Qt差异无统计学意义（P〉0．05）；与Ns组比，Dex组T5时PaO2升高，Qs／Qt降低（P〈0．05）。结论Dex在食管癌手术患者中能明显改善恢复TLV后PaO2及Qs／Qt。

Objective To observe the effects of dexmetomidine on OLV intrapulmonary shunt in and oxygen pres- sure of the artery during one-lung ventilation undergoing esophageal cancer resection. Methods A total of 40 pa- tients of ASA I or II ,aged 25 - 65 undergoing elective surgery were randomized into two groups of 20 each. Dex group and normal saline （NS） group. Dex group used Dex 0.6μg/kg within 10 rain as a bolus and then main- tained at 0.4 μg/（ kg. h） , before the end of the operation 30 rain. The same volume of NS was given in the same manner in NS group. Radial artery and internal jugular vein blood were collected and the blood gas were analyzed at five time points： after anesthesia induction at lateral position TLV 30 min（ T1 ） , OLV 30 rain（ T2 ） , OLv 60 min （ T3 ）, OLV 90 min （ T4 ）, recovering TLV 30 rain （ T5 ）, and then calculating the intrapulmonary shunt and recorded oxygen pressure of the artery. Results There were no significant differences in hemodynamic parameters MAP and BIS between the two groups（P 〉 0. 05 ）. PaO2 was significantly lower, while Qs/Qt was higher at T2-4 than at T1 in group Dex and NS（P 〈0. 05） ; PaO2 was lower,while Qs/Qt was higher at T5 than at T1 in group NS（P 〈0. 05） but there were no statistical differences in group Dex （P 〉 0.05）. PaO2 was higher, while Qs/Qt was lower at T5 in group Dex than in group NS （P 〈 O. 05 ）. Conclusion Dex can improve intrapulmonary shunt and oxygen pressure of the artery significantly in esophageal cancer resection after recovering TLV.