Bain呼吸环路防治单肺通气犬肺内分流量增加的实验研究

对15条单肺通气(OLV)犬模型进行实验,观察手术侧肺加用或不用Bain环路对犬肺分流量和氧合的影响。结果提示:与双肺通气(TLV)相比,不用Bain的OLV犬,动、静脉氧分压(PAO_2、P(?)O_2),动、静脉血氧饱和度(SaO_2、S(?)O_2)分别降低了49％、11％、8％、14％;肺泡气与动脉血氧分压差(_(A-a)DO_2),肺毛细血管-动脉血氧含量差(C_cO_2-CaO_2),肺毛细血管-静脉血氧含量差(C_cO_2-C(?)O_2)和肺分流量(Q_(?)/Q_t),分别增加了39％、350％、50％和190％(均为P<0.01)。提示低氧血症与OLV时严重肺内分流、静脉血掺杂有关。而使用Bain的OLV犬氧合良好,PaO_2、P(?)O_2稍有增高,~(A-a)DO_2和Q_(?)/Q-t分别降低了19.3％和8％(均为P>0.05)。Bain环路能将氧气以一定的压力和流速持续吹入肺泡,使其扩张并行气体交换,达到改善术侧肺功能和防治肺内分流量增加的目的。

Study of the Bain Respiratory Cycle Used to Prevent Increase of Intrapulmonary Shunt and Reduce Hypoxemia during One-Lung Ventilation in Canine Models

15 dogs in one-lung ventilation (OLV) were used, to observe whether oxygen insufflation in-to the upper nonventilated lung at 0. 5 bar CPAP via Bain respiratory cycle during one-lung anesthesia would diminish transpulmonary right-to-left shunt and also improve oxygenation. Significant differences were deter-mined in arterial and venous oxygen tension (PaO2 and PvO2), arterial and venous oxygen saturation(SaO2and SvO2), alveolar-arterial oxygen tension difference (DO2) and Q./Qt between dogs in whpm oxygen was not insufflated (only OLV), and those in which oxygen via Bain Cycle in nonventilated lung was insufflated (OLV Bain). When the nonventilation lung of the dog was deflated, it had significantly lower PaO2 ,PvO2,SaO2and SvO2(about 49 %, 11 %, 8 % and 14 %), higher ADO2, CcO2-CaO2, CcO2-C,O2 and Q/Q,(39 %, 350 %, 50 % and 190 % ) (P<0. 01 ) compared to two-lung ventilation (TLV). The results indicated that hypoxemia was due to a greatly increased venous admixture through the nonventilated upper lung. How-ever, the above parameter by OLV Bain was slightly variable and no significant differences were observed when compared with the TLV treated dogs. Since oxygen could be continuously insufflated into the pul-monary alveoli through the Bain cycle and gas exchange was completed at the expansive alveoli, obvious ef-fects could be obtained of reducing intrapulmonary shunt and improving pulmonary function during OLV.