Effects of Intrapleural Pressure on Phrenic Nerve Activity

胸膜腔內壓對膈神經活動性的影響

李不偏(B. P. Lee) ； 姜壽德(S. T. Chiang) ； 黃基礎(J.-C. Hwang)

《The Chinese Journal of Physiology》 29卷2期 (1986/12) Pp. 79-90

摘要

當呼吸系統機械學的特性(Mechanics)改變時，探討其對膈神經(Phrenic nerve)活動性及呼吸輸出量(Respiratory mechanical output)間相互關係的影響。以氯醛糖(α-Chloralose)麻醉的狗為實驗動物。將定量空氣注入狗胸膜腔內，以增加胸膜腔內壓，造成密閉氣胸(Closed pneumothorax)，做為改變呼吸系統機械學的特性之方法。
以呼吸氣流速度描記器(Pneumotachograph)測量記錄狗的呼吸輸出量，並同時測量分析膈神經的活動性。在改變呼吸機械學的特性之前後，同時測量記錄並分析比較，膈神經活動性與呼吸輸出量間的關係。當造成氣胸時（胸膜腔內壓接近大氣壓力），肺及胸腔壁的彈性係數(Compliance)，吸氣時間及潮氣容積皆顯著減少；而膈神經的活動性則顯著的增加。呼吸輸出量及膈神經活動性之間的差異也隨著顯著加大。由實驗結果，認為膈神經活動性的增加，主要是因肺內感受器(Intra-pulmonary recepors)活動性的改變所引起；而潮氣容積的減少係因呼吸機械學的特性改變所致。

並列摘要

Lee, B. P., S. T. Chiang, and J. C. Hwang: Effect of intrapleural pressure on phrenic nerve activity. Chinese J. Physiol. 29(2): 79-90, 1986: In order to evaluate the effect of changing respiratory mechanics on the relation between respiratory mechanical output and phrenic activity, we simultaneously measured ventilatory output from the trace of pneumotachograph and changes in phrenic nerve activity before and after pneumothorax in alpha-chloralose anesthetized dogs. After pneumothorax, the dynamic lung compliance, inspiratory duration and tidal volume were decreased significantly, whereas the integrated peak amplitude and the rate of rise of phrenic neural output were increased substantially. The difference between respiratory mechanical output and phrenic activity was also significant (p＜0.05). As shown from the results, the increase of phrenic response to pneumothorax may be mediated through intrapulmonary receptors along the vagal afferent rather than through the changes in chemical drive.

並列關鍵字

Pneumothorax ； Respiratory mechanics ； Phrenic nerve activity ； Ventilatory output