气管内吹气对支气管痉挛家兔血气及呼吸力学的作用

EFFECTS OF TRACHEAL INSUFFLATION ON METHACHOLINE INDUCED BRONCHIAL SPASM RABBITS

为探讨气管内吹气（ＴＧＩ）对支气管痉挛家兔动脉血气及呼吸力学的影响。用自行设计的ＴＧＩ装置对实施常规机械通气（ＣＭＶ）和容许性高碳酸血症（ＰＨＣ）机械通气的支气管痉挛家兔行ＴＧＩ，观察乙酰甲胆碱（Ｍｃｈ）诱发支气管痉挛前后ＰａＣＯ２、气道峰压（Ｐｐｅａｋ ）、平台压（Ｐｐａｕｓｅ）等生理指标的变化。结果：ＰＨＣ机械通气时并用ＴＧＩ可明显降低ＰａＣＯ２ 水平，促进体内ＣＯ２ 清除，并能在潮气量（ＶＴ ）降低３３％ 的情况下维持ＰａＣＯ２ 在正常范围；ＴＧＩ可使气道压力增高，但ＰＨＣ时并用ＴＧＩ的Ｐｐｅａｋ 、Ｐｐａｕｓｅ水平均显著低于ＣＭＶ时。本研究结果提示，ＴＧＩ是一种简便实用的机械通气的辅助手段，它能有效的降低ＰａＣＯ２ ，能在ＰＨＣ状态下抑制或减缓ＰａＣＯ２ 的上升速度。

To evaluate the effects of tracheal insufflation(TI) on the elimination of CO 2 and airway pressure in methacholine (Mch) induced rabbit bronchial spasm. Using self designed TI device, TI was given with different flows(0.02 and 0.4L/min) to rabbits with mathacholine induced bronchial spasm under. conventional mechanical ventilation (CMV) and permissive hypercapnia (PHC), and PaCO 2, peak pressure (P peak ), and pause pressure (P pause ) were determined. TI can significantly decrease the PaCO 2 level, enhance CO 2 elimination and maintain PaCO 2 in the normal range while decreasing V T by 33%. TI can elevate airway pressure in both CMV and PHC period, but the level of P peak 、 P pause in PHC period are significantly lower than those of CMV. Our results revealed that TI is a simple and practical adjunct to mechanical ventilation, it can effectively decrease PaCO 2, impeding rise of PaCO 2 under PHC condition, and maintain low airway pressure.