三种加压呼吸水平下不同胸部对抗压时的心血管反应

Cardiovascular Responses to G-suits with 3 Levels of Positive Pressure Breathing Using Different Chest Counter Pressures.

目的探讨加压呼吸时胸部对抗压对心血管的影响。方法观察 7名 1 8～ 2 0岁健康男性青年穿两种背心抗荷裤 ,在 30、5 0、70mmHg 3种加压水平 ,持续 3min加压呼吸的心血管反应。 结果所有被试者均完成试验。在加压值为 5 0、70mmHg持续 3min时 ,与各自对照组比 ,HR、MAP及TPR明显提高 ,SV明显降低 ,Q Z间期在各加压值加压呼吸时无明显变化。两种装备在 70mmHg加压呼吸时ΔSV、ΔTPR有显著性差异 (P <0 .0 5 )。结论使用这两种装备进行加压呼吸均可造成MAP、TPR和HR明显增加 ,SV明显减少。加压呼吸对心肌收缩功能并无影响。在加压呼吸条件下 ,胸部对抗压与面罩腔内压力相等 。

Objective To observe cardiovascular responses to positive pressure breathing (PPB) using different counter pressures. Method Cardiovascular responses of 7 male healthy subjects (aged 18～20 years ) wearing two kinds of Jerkin G suit were observed under three levels of ground level PPB(30,50,70 mmHg) for 3 min. Result All subjects completed the experiment successfully .While during PPB at 50?70 mmHg levels within 3 min, HR,MAP,TPR elevated significantly, while SV declined significantly. At all 3 PPB levels Q Z time was not significantly changed. There were significant difference (P<0.05) between ΔSV and ΔTPR with the two Jerkin G suits under PPB of 70 mmHg. Conclusion PPB resulted in elevation of MAP,TPR,HR and decline of SV significantly using two kinds of Jerkin G suit . PPB had no effect on contractile function of cardiac muscle .Under PPB, SV increased significantly when chest counter pressure was equal to the mask pressure.