模拟高原环境导致的低碳酸血症对家兔肺动脉压力的影响

目的 探讨模拟高原环境导致的低碳酸血症对家兔肺动脉压力的影响。方法 选择10只健康雄性家兔行气管插管、肺动脉插管并给予机械通气,通过调整呼吸机参数造成低碳酸血症。按照血气分析结果分为五个阶段,空白对照阶段、无低碳酸血症阶段、轻度低碳酸血症阶段、中度低碳酸血症阶段、重度低碳酸血症阶段。每个时间段先采集动脉和静脉血用于血气分析和血管紧张素Ⅱ（AngⅡ）测定,然后行平均肺动脉压力测定。结果 随着家兔PaCO2逐渐降低,家兔平均肺动脉压力和血清AngⅡ均明显降低,差异有统计学意义（P均〈0.05）。结论 模拟高原环境所导致的低碳酸血症能降低肺动脉压力,可能与血清AngⅡ水平降低有关。

Effects of hypocarbia caused by simulated high altitude environment in pulmonary artery pressure of rabbit

Objective To observe the effects of hypocarbia caused by simulated high altitude environment in pulmonary artery pressure of rabbit. Methods Conducted tracheal intubation, pulmonary arterial intubation as well as mechanical ventilation to develop hypocarbia （based on the parameters from the ventilation machine）. Based on the blood gas analysis, we classified them into 5 phase, blank control phase, non-hypocarbia phase, mild hypocarbia phase, moderate hypocarbia phase and severe hypocarbia phase. During each phase, we conducted blood gas analysis and angiotensin Ⅱ measurement on arterial and venous blood respectively. Results Within the reduction of PaCO2, the average pulmonary artery pressure, angiotensin Ⅱ level are significantly decreased （P 〈 0. 05 ） in rabbits. Conclusions The reduction of angiotensin Ⅱ may cause the decreases of pulmonary arterial pressure caused by the hypocarbia in stimulated high altitude.