Rubal B J, Buchanan C
Lab Anim Sci. 1986 Feb;36(1):59-64.
This study evaluated the cardiorespiratory stability of six dose-regulated, 12-hour, chloralose anesthetic maintenance protocols. Thirty mongrel dogs were premedicated with morphine sulfate (5mg/kg) and anesthetized with an induction dose of chloralose (80mg/kg). Fifteen animals were permitted to breathe spontaneously and 15 animals were ventilated mechanically to maintain a constant arterial pCO2 (40 +/- 5 mmHg). The spontaneously breathing dogs were separated into three groups in which animals (n = 5) were given different bolus doses of supplemental anesthetic. Initially the spontaneously breathing animals were hypoxemic, acidemic and hypercapnic. No consistent hemodynamic difference was noted among these groups. The mechanically ventilated animals were also divided into three groups that received varying doses of supplemental chloralose by constant infusion. Significant (p less than 0.01) myocardial depression was noted in the heavy-dosed animals by the third hour. Systolic pressure decreased 44%, pulse pressure decreased 37% and peak left ventricular dP/dt decreased 52%. All heavy-dosed animals expired before the eighth hour. Although these data suggest that morphine-premedicated, chloralose-anesthetized animals generally provide a stable cardiopulmonary model, high-dose chloralose supplementation depressed ventilation and produced a dose-dependent cardiotoxicity.
本研究评估了六种剂量调节的、持续12小时的水合氯醛麻醉维持方案的心肺稳定性。30只杂种犬先用硫酸吗啡（5mg/kg）进行预处理，然后用诱导剂量的水合氯醛（80mg/kg）麻醉。15只动物允许自主呼吸，15只动物进行机械通气以维持恒定的动脉血二氧化碳分压（40±5mmHg）。自主呼吸的犬被分为三组，每组动物（n = 5）给予不同剂量的补充麻醉剂推注。最初，自主呼吸的动物存在低氧血症、酸血症和高碳酸血症。这些组之间未观察到一致的血流动力学差异。机械通气的动物也分为三组，通过持续输注给予不同剂量的补充水合氯醛。到第三小时时，高剂量组动物出现显著（p < 0.01）的心肌抑制。收缩压下降44%，脉压下降37%，左心室dp/dt峰值下降52%。所有高剂量组动物在第八小时前死亡。尽管这些数据表明，用吗啡预处理、水合氯醛麻醉的动物通常能提供一个稳定的心肺模型，但高剂量补充水合氯醛会抑制通气并产生剂量依赖性心脏毒性。
