護理師教導一位慢性阻塞性肺病（COPD）患者運用「噘嘴式呼吸」。下列哪項說明最正確？
A nurse is educating a client with chronic obstructive pulmonary disease (COPD) on pursed-lip breathing. Which of the following explanations should the nurse provide?
- AIt promotes coughing to clear the airway促進咳嗽以清除呼吸道
- BIt helps to prevent early airway collapse during exhalation✓ 正解有助於防止呼氣時氣道早期塌陷
- CIt assists in collapsing the small airways to clear mucus協助小氣道塌陷以清除黏液
- DIt helps to increase the oxygen intake有助於增加氧氣攝取
噘嘴式呼吸（Pursed-lip breathing）是 COPD 病人的呼吸訓練重點。其核心機轉在於呼氣時噘起嘴唇，增加呼氣阻力，從而提升呼氣期的氣道內壓力。這能防止受損的支氣管在呼氣時因肺彈性回縮力不足而過早塌陷（Airway collapse），使滯留於肺部的氣體更容易排出，改善肺泡換氣效率。
Pursed-lip breathing is a key respiratory technique for clients with chronic obstructive pulmonary disease (COPD). The core mechanism is that pursing the lips during exhalation increases expiratory resistance, raising the airway pressure during expiration. This back-pressure prevents the damaged bronchi from collapsing prematurely due to reduced lung elastic recoil, allowing trapped air to escape more effectively and improving alveolar ventilation.