Mechanical insufflation-exsufflation-related bilateral pneumothorax.

Mechanical insufflation-exsufflation (MI-E) devices are frequently used in patients with respiratory muscle weakness to increase their cough peak flow and assist them in improving cough effectiveness and clearing mucus from the airways. An 89-year-old male was admitted to our university hospital due to fever and loss of appetite. He was diagnosed with lung abscess and pulmonary nontuberculous mycobacterial disease. He was unable to independently expectorate phlegm due to frailty. Subsequently, MI-E was introduced. On day 3 after its introduction, chest X-ray examination revealed bilateral pneumothorax, and use of the MI-E device was discontinued. After conservatively observing the clinical course, pneumothorax was improved on day 12 after it occurred. Although scientific evidence regarding MI-E is currently limited, healthcare professionals often do not have an alternative in clinical practice. However, treating physicians should consider the risk of MI-E-related pneumothorax, despite its low occurrence rate.