论文部分内容阅读
目的研究呼气末正压通气（ＰＥＥＰ）时内脏交感神经活动的变化及其机制。方法麻醉犬在使用０．９８ｋＰａ（１ｋＰａ＝１０．２ｃｍＨ２Ｏ）ＰＥＥＰ的过程中，同时直接测定了肾脏、心脏、肝脏及肾上腺交感神经放电活动和血液动力学变化。实验分为迷走神经保留组和迷走神经切断组。结果在神经保留时，使用ＰＥＥＰ使肾上腺交感神经活动受到明显抑制（Ｐ＜０．０５），肾脏、心脏及肝脏交感神经活动均呈减少趋势（Ｐ＞０．０５）。迷走神经切断使上述内脏交感神经活动增加。使用ＰＥＥＰ时，中心静脉压、左心房压及气道内压明显上升，而平均动脉压明显下降。结论ＰＥＥＰ可通过刺激心肺感受器的迷走神经使肾上腺、肾脏、心脏及肝脏交感神经活动减少，而内脏交感神经活动减少可能是引起体动脉血压下降和心搏出量减少的主要原因之一。
Objective To study the changes and mechanisms of visceral sympathetic activity during positive end expiratory pressure (PEEP). Methods The anesthetized dogs were treated with 0.98 kPa (1 kPa = 10.2 cm H2O) of PEEP, and the changes of sympathetic nerve activity and hemodynamics of the kidneys, heart, liver and adrenal glands were also measured directly. The experiment was divided into vagal nerve preservation group and vagotomy group. Results During the nerve preservation, the use of PEEP significantly inhibited the sympathetic activity of the adrenal gland (P <0.05), while decreased the activity of sympathetic nerves in the kidney, heart and liver (P> 0.05). Vagus nerve transection increases the visceral sympathetic activity. Using PEEP, central venous pressure, left atrial pressure and airway pressure increased significantly, while the average arterial pressure decreased significantly. Conclusions PEEP can reduce sympathetic activity of the adrenal gland, kidney, heart and liver by stimulating the vagus nerve of cardiopulmonary receptors. The decrease of visceral sympathetic activity may be one of the main causes of the decrease of arterial blood pressure and cardiac output.