PERFUSION DISTRIBUTION AND LUNG THERMAL VOLUME IN CANINE HYDROCHLORIC-ACID ASPIRATION
PERFUSION DISTRIBUTION AND LUNG THERMAL VOLUME IN CANINE HYDROCHLORIC-ACID ASPIRATION
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DOI：
10.1152/jappl.1988.65.2.750
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发表时间：
1988-08-01
影响因子：
3.3
通讯作者：
GRAY, BA
中科院分区：
文献类型：
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作者：
CARLILE, PV;HAGAN, SF;GRAY, BA
本实验观察了短时呼气末正压(PEEP)通气和硝酸甘油(NTG)输注对单侧HCl肺损伤犬肺血流量和血管外热容量(ETV)分布的影响。ETV用热染色技术测定，用单指数外推法排除再循环指示剂，局部血流量用颗粒分布技术(放射性标记塑料微球)测定。动物处死后称肺重量，并用血红蛋白测定血管外肺质量(ELM)，以校正滞留的肺血。分别于右肺注入盐酸前、PEEP期间和注入NTG前、中、后3h重复测量。右肺严重损伤部分的血流灌注分数(.ovrhdot.Qini/.ovrhdot.Qt)从44.3.+-下降。基准线为11.1%，至27.8.+-。肺损伤起病后15.4%。PEEP引起ETV的急性可逆性增加(63。+-。ETV的变化与.ovrhdot.Qinj/.ovrhdot.Qt的变化密切相关(r=0.91)。NTG输注使ETV(14。+-)增加不明显。比输液前和输液后平均值高10%)和.ovrhdot.Qinj/.ovrhdot.Qt(59.+-)。35%)，但ETV与.ovrhdot.Qinj/.ovrhdot.Qt的变化密切相关(r=0.92)。热稀释测量检测到的血管外肺质量分数平均为0.44(范围0.24-0.77)。我们得出结论：1)给药和停用PEEP或静脉注射NTG引起的ETV的变化是由肺血流分布的变化而不是肺水含量的变化来解释的；2)在该模型中，ETV测量的ELM分数由相对于肺水肿的血流分布来确定。
We investigated the effects of a brief period of positive end-expiratory pressure (PEEP) ventilation or nitroglycerin (NTG) infusion on the distribution of pulmonary blood flow and extravascular thermal volume (ETV) in anesthetized dogs with unilateral HCl lung injury. ETV was determined by the thermal dye technique by use of a monoexponential extrapolation to exclude recirculating indicator, and regional blood flow was determined by a particle distribution technique (radiolabeled plastic microspheres). The lungs were weighed after the animals were killed, and extravascular lung mass (ELM) was determined with the use of hemoglobin to correct for trapped lung blood. Measurements were obtained before instillation of HCl into the right lung and repeated 3 h later before, during, and after PEEP ventilation or NTG infusion. Fractional perfusion of the severely injured portion of the right lung (.ovrhdot.Qini/.ovrhdot.QT) fell from 44.3 .+-. 11.1% at base line to 27.8 .+-. 15.4% after the onset of lung injury. PEEP produced an acute reversible increase in ETV (63 .+-. 37% over average of pre- and post-PEEP values), and the changes in ETV were closely correlated with changes in .ovrhdot.Qinj/.ovrhdot.QT (r = 0.91). NTG infusion produced insignificant increases in ETV (14 .+-. 10% over average of pre- and postinfusion values) and .ovrhdot.Qinj/.ovrhdot.QT (59 .+-. 35%), but the changes in ETV and .ovrhdot.Qinj/.ovrhdot.QT were strongly correlated (r = 0.92). The fraction of extravascular lung mass detected by the thermodilution measurement averaged 0.44 (range 0.24-0.77). We conclude that 1) changes in ETV resulting from the administration and withdrawal of PEEP or intravenous NTG are explained by changes in the distribution of pulmonary perfusion, not by changes in lung water content; and 2) the fraction of ELM measured as ETV is determined by the distribution of blood flow relative to lung edema in this model.