Pulmonary barotrauma 肺部氣壓傷

(Tintinalli's Emergency Medicine)
Pulmonary barotrauma 肺部氣壓傷. 也叫做 pulmonary overinflation 肺部過度充氣症, burst lung syndrome肺爆裂症

上升過程因故意閉氣,咳嗽,嘔吐等動作造成聲帶關閉, 造成肺部氣壓大於外界, 通常發生於恐慌的潛水員或氣瓶用盡而快速上升,造成肺部過度膨脹引起氣壓傷, 在淺水也可能發生(例如游泳池), 可導致縱膈腔氣腫. 

縱膈腔氣腫: 胸部x光可能沒有明顯異常. 通常不需要高壓氧治療, 症狀治療即可(疼痛則給予止痛), 縱膈腔氣體可能會沿著皮下跑到頸部引起頸部皮下氣腫, 肺部過度膨脹可能造成氣胸 (有些患者可能須用空針抽出氣胸部位的氣體, 有些可能需放置胸管)

如果氣體進入肺部靜脈循環, 可能之後進入動脈循環引起動脈氣栓, 對於氣栓最敏感的器官是腦部, 這種情況稱腦部動脈氣栓  cerebral arterial gas embolism , 但氣栓可能同時散步到其他器官或組織, 上升過程的氣壓傷害如果同時合併中樞神經受損症狀, 要考慮腦部動脈氣栓

有些人因為其他疾病, 可能在沒有閉氣上升, 沒有快速上升的情況出現肺部氣壓傷(例如肺囊腫 lungcyst, 肺部阻塞性疾病, 或其他可能造成肺臟局部氣體滯留的疾病)

Air also expands within the lungs with ascent. If a diver breathing compressed air ascends with a closed glottis (holds breath, coughs, vomits), most frequently seen in a rapid, panicked, out-of-air ascent, the expanding air may cause parenchymal lung injury. This can occur even in shallow water (e.g., a swimming pool). Pulmonary barotrauma, also called pulmonary overinflation or burst lung syndrome, can lead to pneumomediastinum. This generally only requires symptomatic treatment and may be subtle on the chest radiograph. Mediastinal air can track superiorly into the neck, resulting in subcutaneous air on physical examination or air on a cervical spine radiograph. Pulmonary overinflation injury can cause pneumothorax, requiring aspiration or air or tube thoracostomy. If air enters the pulmonary venous circulation, embolization of the gas through the arterial system occurs. The most sensitive end-organ to such embolization is the brain, and cerebral arterial gas embolism is the term applied to this condition, although the air emboli distribute to other tissues and organs. Any neurologic symptom or sign referable to the circulation to the CNS in the setting of barotrauma associated with ascent should be considered to be secondary to cerebral arterial gas embolism. Pulmonary barotrauma (Figure 214-1) can occur without a rapid ascent or closed glottis in divers with congenital cysts, obstructive pulmonary disease, or other processes that cause air trapping.