Fahey J T, Lister G
Am J Physiol. 1985 Jul;249(1 Pt 2):H188-92. doi: 10.1152/ajpheart.1985.249.1.H188.
We have developed a method for reducing cardiac output in a controlled stepwise fashion using awake, intact, unsedated lambs. The method involves placing a balloon-tipped (Foley) catheter into the right atrium from a jugular vein isolated by a small neck incision. Systemic venous return and cardiac output are limited by balloon inflation. With each balloon inflation the animal reaches a new and stable cardiac output, which allows the measure of steady-state hemodynamic and metabolic variables. We have been able to decrease cardiac output to as low as 20% of the resting cardiac output and maintain a stable preparation. The reductions in cardiac output are quickly reversible by balloon deflation. Animal survival allows repeated study. We present data from five lambs studied between 26 and 36 days of age. Alterations in O2 consumption, O2 transport, O2 extraction, blood pressure, and arterial lactate concentration are examined in response to decrements in systemic blood flow and are consistent with changes seen in response to a reduction of cardiac output by other methods.
我们已经开发出一种方法，可在清醒、完整、未使用镇静剂的羔羊身上以可控的逐步方式降低心输出量。该方法包括通过一个小的颈部切口分离颈静脉，将带球囊尖端（弗利氏）导管经颈静脉插入右心房。通过球囊充气来限制体循环静脉回流和心输出量。每次球囊充气时，动物都会达到一个新的稳定的心输出量，这使得能够测量稳态血流动力学和代谢变量。我们已经能够将心输出量降低至静息心输出量的20%，并维持稳定的状态。通过球囊放气，心输出量的降低可迅速逆转。动物存活使得可以重复进行研究。我们展示了5只26至36日龄羔羊的研究数据。研究了随着体循环血流量减少，氧气消耗、氧气运输、氧气提取、血压和动脉乳酸浓度的变化情况，这些变化与通过其他方法降低心输出量时所观察到的变化一致。
