‘peal’ of cough？怎么理解？

Cough Reflex

This may be elicited by chemical or mechanical stimuli arising in the larynx, trachea, carina or main bronchi. Which of these sites is responsible for the initiation of a cough is difficult to determine. For chemical stimuli the larynx may be of less importance, as superior laryngeal nerve block has little effect on cough stimulated by citric acid inhalation, and in patients following a heart–lung transplant, inhalation of the normally potent stimulant distilled water results in little or no cough (page 409). Coughing can be initiated or partially inhibited voluntarily, but the reflex is complex and comprises three main stages:

咳嗽反射^14,15

咳嗽反射可能是由喉、气管、隆突或主支气管内的化学或机械刺激引起的，很难确定这些部位中哪个引起了咳嗽。对于化学刺激，喉部可能不是重要部位，因为喉上神经阻滞几乎不能抑制柠檬酸误吸引发的咳嗽，并且在心肺移植后的患者中，误吸常规刺激剂量的蒸馏水也几乎不引发咳嗽（第409页）。咳嗽可以自发开始或部分抑制，但其反射很复杂，包括三相：

1. Inspiratory phase. Takes into the lungs a volume of air sufficient for the expiratory activity.

2. Compressive phase. Involves a forced expiration against a closed glottis. Transient changes of pressure up to 40 kPa (300 mmHg) may occur in the thorax, arterial blood and the cerebrospinal fluid (CSF) during the act of coughing.

3. Expulsive phase. The glottis opens, allowing rapid expiratory flow throughout the respiratory tract.

1. 吸气相 吸入足以呼气的气体量。

2. 压缩相 包括在声门闭合时的用力呼气。咳嗽时，胸部、动脉血和脑脊液（CSF）的瞬时压力可高达40 kPa（300 mmHg）。

3. 排出相 声门打开，允许呼气流快速通过呼吸道。

During this last phase the velocity of gas flow will be greatest in the narrowest section of the airway, usually the large bronchi, trachea and larynx (see Fig. 1.5), an area referred to as the ‘choke point’. This high-velocity gas, with its turbulent flow, increases the shear forces between the gas and airway lining fluid, which is dragged from the airway wall and swept up towards the pharynx. The transient high intrathoracic pressure generated during a cough is believed to compress the large airways despite their cartilaginous support, and this narrowing further increases the gas velocity, reaching levels much higher than can be achieved by a voluntary forced expiration. The gas velocity achieved, and so the efficiency of the cough, is highly dependent on the size of breath taken during the inspiratory phase (Fig. 4.5).Finally, a series of smaller expulsive phases after a single inspiration, referred to as a ‘peal’ of coughs, is commonly seen and may be more effective at removing secretions than a single larger volume cough.

在排出相，气道最窄部分（通常是大支气管、气管和喉）流度最大（见图1.5），该区域称为“阻塞点”。这些湍流的高速气体，增加了气体和气道内衬液之间的剪切力，使得气道内衬液从气道壁快速移动到咽部。尽管大气道有软骨支持，但咳嗽时产生的瞬时胸内高压也压迫了大气道，而且这种气道狭窄会进一步加快气流流速，使之远高于自主用力呼气时的流速水平，吸气相的效率高度决定了排出相的气流速度以及咳嗽的效能（图4.5）。最后，单次吸气后出现一系列稍小的排出相，称为“阵咳”，这种情况很常见，并且可能比单次剧烈咳嗽能更有效地清除分泌物。¹⁵

‘peal’ of cough？怎么理解？“阵咳”？“响亮的咳嗽”？网上只查到这个