Experimental study of extracorporeal lung assist in rat

我们利用微型膜氧合器（Mini-ECLA系统）研究了V-V和V-A旁路体外肺辅助（ECLA）对大鼠的影响。Wistar大鼠全身麻醉，腹腔注射戊巴比妥（50mg /kg），气管切开通气。V-V和V-A ECLA分别采用6fr . atom导管或18g institute导管经颈静脉经右心房引流，采用24G Therflow导管分别经股静脉或颈总动脉回流。我们使用了一种为大鼠研制的微型密膜中空纤维充氧器（启动体积4 ml）。mini-ECLA回路的总启动体积为20毫升，V-A ECLA维持时间最长为150分钟（平均持续时间：83分钟）。(61分钟)和旁路流获得35.0 (SY。+ -。[)3.3毫升/公斤/分钟(平均(SY。+ -。(SD)。对氧合器进出口间的血气分析表明，氧合器具有较高的氧合性和CO<@D22@>D2的去除率；在ECLA期间，气体交换得到了很好的维持。ECLA开始后5min血红蛋白、血浆蛋白浓度和红细胞压积分别为6.8 g/dl、4.0 g/dl和18.3%，在ECLA过程中保持稳定。与ecla前相比，由于大鼠相对较大的启动体积导致血液稀释，该值显着降低。此外，在V-A型ECLA中发生的高钾血症可能是由于滚柱泵的溶血，但其他电解质没有明显改变。在未来的工作中，我们需要构建更小的电路来防止血液稀释，并改善引流，以避免ECLA期间溶血导致的高钾血症。该微型ECLA系统延长了大鼠ECLA时间，可用于体外循环效果的研究。

We investigated the effects of V-V and V-A bypass extracorporeal lung assist (ECLA) using a miniature membrane oxygenators (Mini-ECLA system) in rats. Wistar rats underwent general anesthesia with intraperitoneal pentobarbital administration (50 mg/kg) and tracheostomy for ventilation. V-V and V-A ECLA were carried out through the right atrium via a jugular vein using a 6 Fr.Atom catheter or 18 G Instite catheter for drainage, respectively, and return flow through the femoral vein or common carotid artery, respectively, using a 24G Therflow catheter. We used a miniature dense-membrane, hollow-fiber oxygenator which was developed for rat (priming volume 4 ml). Total priming volume in mini-ECLA circuits was 20 ml.We maintained the V-A ECLA for a maximum of 150 min (mean duration : 83(]SY.+-。[)61 min) and obtained bypass flow of 35.0(]SY.+-。[)3.3 ml/kg/min (mean(]SY.+-。[)SD). Analysis of blood gases between inlet and outlet of the oxygenator revealed that high oxygenation and CO<@D22@>D2 removal were obtained in the oxygenator ; gas exchange was well maintained during ECLA.The values of hemoglobin, plasma protein concentration and hematocrit at 5 min after ECLA start were 6.8 g/dl, 4.0 g/dl and 18.3 %, respectively, and were stable during the ECLA.The values were significantly decreased compared to the pre-ECLA values due to hemodilution by the relatively large priming volume for rat.Furthermore, hyperkalemia that occurred in V-A ECLA was likely due to hemolysis by the roller pump, however other electrolytes were not significantly changed. In future work we need to construct smaller circuits to prevent hemodilution and improve drainage to avoid hyperkalemia due to hemolysis during ECLA.This mini-ECLA system achieved to prolonged time on ECLA in rats and may be useful for investigation of the effects of extracorporeal circulation.