20mL小儿罗叶泵的动物存活实验

Animal survival experiment of 20mL pediatric Luo-Ye ventricular assist pump

目的采用自行研制的20 mL小儿罗叶泵行动物存活实验,明确其对血细胞和重要器官的影响,探讨临床应用的可行性。方法健康山羊6只,体重(18±3.3)kg。经左侧第5肋间进胸,以左室心尖及降主动脉的插管方式建立左心辅助循环。止血关胸,清醒后拔除气管插管,动物置于专用饲养笼内。辅助期间持续静脉给予肝素抗凝,维持激活全血凝固时间(activated clotting time,ACT)在180～250 s。经颈动、静脉置管监测中心静脉压和血压。在辅助前,辅助后1 h、3h、6 h、10 h、16 h、24 h及存活期间每24 h监测血浆游离血红蛋白,在辅助前及存活期间每24 h检测血常规、肝肾功能、凝血指标。实验结束时取动物心、肝、肾、肺观察病理变化。结果开胸后插管时发生顽固性室颤死亡1只,其余5只成功进行存活实验,平均存活时间(79.8±60)h。其中因栓塞死亡1只,胸腔出血、肺部感染死亡1只,肝素连接管脱落出血致失血性休克1只,反复气胸、ACT过高致脏器出血1只。1只山羊在存活至预定的7 d时,再次麻醉插管,开胸撤离辅助装置,关胸后顺利拔除气管插管,动物存活。辅助过程中肝素抗凝剂量25～35u/(kg.h),所维持的ACT具足够的抗凝效果。中心静脉压、平均动脉压、肝肾功能在辅助前后无明显变化。血浆游离血红蛋白由辅助前的(2.227±1.321)mg/dL升高到辅助72h的(8.873±2.510)mg/dL,二者相比有统计学差异,但在正常生理值范围内。除第1例因抗凝不足产生肾栓塞外,其余4例心、肝、肾、肺的病理检查均无栓塞。结论 20mL小儿罗叶泵血液相容性好,对肝肾功能无不良影响,具备用于临床的条件。

Objective To study the influence of 20mL pediatric Luo-Ye ventricular assist pump on blood cells and the functions of critical organs, to identify the possibility of pediatric Luo-Ye pump in clinical practice. Methods Six healthy goats weighted （ 18 ± 3.3 ） kg. Left anterolateral thoracotomy through the left fifth intercostal space ventricular assistance was was performed. Left established in the way of from left ventricular apex to descending aorta. Chest was closed after the implantation, and the tracheal intubation was extracted when the goat was alert and recovered spontaneous breathing. Intravenous heparin was given continuously tomaintain activated clotting time （ACT） at 180 - 250 s during the assistance. Central venous pressure and blood pressure were monitored through internal carotid artery and jugular vein catheterization. Blood sample was drawn for plasma free hemoglobin （FHB） test before assistance, l＇h, 3h, 6h, 10h, 16h, 24h after assistance, and each 24h during the assistance. Blood routine, hepatic function, renal function and coagulation index were tested before the assistance and each 24h during the assistance. Specimens of heart, liver, kidney and lung were harvested for pathological examination. Results Refractory ventricular fibrillation occurred in one goat, successful experiments were performed in 5 goats and the survival time was （79.8 ±60） h. Of the five goats, one died of embolism, thoracic cavity bleeding and pulmonary infection occurred in 1 case, hemorrhagic shock resulted from venous channel disconnection in 1, and pneumothorax in 1. One goat was alive on the 7th day, which was weaned from the Luo-Ye pump successfully, and tracheal intubation was extracted evenly after closing the chest. This goat recovered very well. Heparin was used for anticoagulation therapy during the left ventricular assistance at the dose of 25 -35u/（ kg · h）, keeping ACT at 180 -250 s that was sufficient and safe for goat during the assistance. The central venous pressure, mean arterial blood pressure, hepatic function, and renal function were of no significant differences pre and post the assistance. The plasma FHB of 72h post assistance [ （8. 873 ±2. 510）mg/dL] was, significantly higher than that of pre-assistance [ （2. 227± 1. 321 ） mg/dL] （P 〈 0. 05） , yet in the normal range. Embolism was not found in the pathological examination except the renal embolism occurred in the first goat due to inadequate anticoagulation therapy. Conclusions The hemocompatibility of the pediatric Luo-Ye ventricular assist pump was good and there was no reverse effect on hepatic function and renal function. The animal survival experiment results demonstrated the pediatric Luo-Ye pump ready to be used in clinical practice.