Hansen P D, Coffey S C, Lewis F R
Department of General Surgery, University of California at San Francisco 94115.
J Surg Res. 1994 Jul;57(1):156-63. doi: 10.1006/jsre.1994.1124.
Adrenergic agents (AAs) have been used in critically ill patients to increase oxygen delivery (DO2). Associated parallel increases in oxygen consumption (VO2) have been noted and are thought to represent improved tissue oxygen utilization at supraphysiologic levels of DO2. We hypothesize that the increase in VO2 associated with the use of AAs in septic animals is secondary to direct, obligate, metabolic effects of the agents themselves. In this study, mongrel dogs were anesthetised, paralyzed, and had minimum temperature maintained on a warming blanket. Pulmonary and systemic hemodynamics were monitored. DO2 was calculated, while VO2 was measured directly with a metabolic cart. All dogs were given an Escherichia coli challenge and a colloid fluid resuscitation. Two hours after the onset of endotoxemia, baseline values were obtained, followed by four progressively larger doses of saline, dobutamine, or dopamine. At each dose there was a 40-min stabilization period and a 20-min measurement of hemodynamics and VO2. Data were analyzed using analysis of variance with a Scheffe's S test. P values of < 0.05 were considered significant. The control group slowly decreased VO2 during the 6-hr experiment to 73% of baseline. Dobutamine increased VO2 to 119% of baseline (31% above control) and dopamine to 111% of baseline (28% over control). We conclude that adrenergic agents cause a significant increase in whole body VO2 at moderate doses in septic dogs. It is likely, therefore, that the "pathologic" relationship between VO2 and DO2 described in critically ill patients is partially due to the direct metabolic effects of AAs.
肾上腺素能药物（AAs）已被用于重症患者以增加氧输送（DO2）。人们注意到氧消耗（VO2）也随之平行增加，并且认为这代表在超生理水平的DO2下组织氧利用得到改善。我们假设，在脓毒症动物中与使用AAs相关的VO2增加是这些药物本身直接的、必然的代谢作用所致。在本研究中，杂种犬被麻醉、麻痹，并通过保温毯维持最低体温。监测肺和全身血流动力学。计算DO2，同时用代谢监测仪直接测量VO2。所有犬均接受大肠杆菌攻击并给予胶体液复苏。内毒素血症发作2小时后，获取基线值，随后给予四剂逐渐增大剂量的生理盐水、多巴酚丁胺或多巴胺。在每个剂量下，有40分钟的稳定期和20分钟的血流动力学及VO2测量期。数据采用方差分析和谢费（Scheffe）S检验进行分析。P值<0.05被认为具有显著性。在6小时的实验中，对照组的VO2缓慢下降至基线的73%。多巴酚丁胺使VO2增加至基线的119%（比对照组高31%），多巴胺使VO2增加至基线的111%（比对照组高28%）。我们得出结论，在脓毒症犬中，中等剂量的肾上腺素能药物会导致全身VO2显著增加。因此，重症患者中所描述的VO2与DO2之间的“病理”关系很可能部分归因于AAs的直接代谢作用。
