EFFECTS OF VENTILATORY MODE ON DIAPHRAGMATIC BLOOD FLOW DURING ENDOTOXEMIA

本研究旨在研究低剂量内毒素（2杯/千克）对自主呼吸犬呼吸肌血流量的影响。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。采用美国ATOM公司的CP-100型肺监测仪，根据食管压力-潮气量曲线计算呼吸功。内毒素给药2 h后，心排血量和血压分别为对照组的54%和56%。即使心输出量确实减少了，但膈肌和其他呼吸肌的血流量增加了大约3倍。肾血流量和消化道血流量减少了约60%。呼吸功比控制值增加48%。这些数据提示，当发生细菌感染时，由于早期呼吸肌肉的血液分布增加，流向肾脏和消化道的血流相对较低灌注状态，而临床表现略有变化。如果低灌注状态持续，肾脏、消化道等脏器功能不全，提示多脏器功能衰竭。我们的结论是，呼吸肌肉和其他主要器官之间的血流分布受到内毒素给药的影响。我们将在未来研究哪种人工通气是合适的，哪种药物治疗更有效。

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.