縱膈腔氣腫是相當罕見但有潛在生命危險的，需要快速的診斷及適當的治療，而它的病因相當廣泛。我們報告首例由於吸食海洛英粉塵引發、並因呼吸器引發之氣壓傷而加劇的縱膈腔氣腫，此例藉由胸部X光片、電腦斷層及氣管鏡檢來確立診斷，並成功的以切開皮膚，藉以引流氣體的方式來治療。吸食海洛英粉塵導致的縱膈腔氣腫的案例相當罕見，應該在有藥物濫用病史的個案，發生胸痛、呼吸困難及皮下氣腫時，列入考慮。而在有使用呼吸器的病人亦要提高警覺，避免氣壓傷加劇了縱膈腔氣腫。

Pneumomediastinum is rare but potentially life-threatened and needs rapid diagnosis and adequate treatment. The etiology varies extensively. We report the first case of pneumomediastinum induced by heroin inhalation and exacerbated by ventilator-induced barotrauma. We approached the case by chest radiography, computed tomography of chest and bronchoscope. We successfully treated the case with skin incision and drainage of air. Pneumomediastinum induced by heroin inhalation is rare and should be taken into differential diagnosis in drug-abused patients who suffer from chest pain, dyspnea, and subcutaneous emphysema of upper trunk. We should also be alert to the patients who are supported by ventilator to avoid exacerbation of pneumomediastinum by ventilator-induced barotrauma.