EFFECTS OF VENTILATORY MODE ON DIAPHRAGMATIC BLOOD FLOW DURING ENDOTOXEMIA

本研究旨在检查低剂量内毒素（2 μ g/kg）对自主呼吸犬呼吸肌血流的影响。用彩色微球示踪技术测定膈肌、其他呼吸肌、肾脏和消化道的血流量。呼吸功采用ATOM公司CP-100型肺功能监测仪，由食管压力-潮气量曲线计算。内毒素给药后2小时，心输出量和血压分别为对照值的54%和56%。即使心输出量减少，流向横膈膜和其他呼吸肌的血流量也增加了约3倍。肾血流量和消化道血流量减少约60%。呼吸功比对照值增加48%。这些数据表明，当发生细菌感染时，尽管临床表现略有变化，但由于呼吸肌的血液分布从早期增加，因此肾脏和消化道的血流相对处于低灌注状态。如果低灌注状态持续，则发生肾、消化道等器官功能不全，提示多器官功能衰竭的发展趋势。我们的结论是，呼吸肌和其他主要器官之间的血流分布受到内毒素的影响。我们将在未来研究什么样的人工通气是合适的，什么样的药物治疗是更有效的。

This study was designed to examine the effects of low dose endotoxin (2 mug/kg) on respiratory muscle blood flow in spontaneously breathing dogs. Blood flow to diaphragm, other respiratory muscles, kidney, and alimentary canal was measured by colored microsphere tracing technique. The work of breathing was calculated from esophageal pressure-tidal volume curve by using pulmonary monitor CP-100 (ATOM Co.). Two hours after endotoxin administration, cardiac output and blood pressure amounted to 54% and 56% of the control value, respectively. And even if cardiac output did decrement, the blood flow to diaphragm and other respiratory muscles increased in approximately 3 times. The renal blood flow and the alimentary canal blood flow did decrement in approximately 60%. The work of breathing increased by 48% of control value. These data suggested that when bacterial infection has occurred, the blood flow to the kidney and alimentary canal was become low perfusion state relatively because of increment of the blood distribution to the respiratory muscles from early stage thought clinical manifestation was slightly changes. If low perfusion state lasts, organ incompetence such as kidney, alimentary canal happens, and suggests potency developing in multiple organ failure. We conclude that blood flow distribution between the respiratory muscles and other major organs was affected by endotoxin administration.We will examine what kind of artificial ventilation is appropriate and what kind of drug therapy is more effective in future.