[Pneumothorax, pneumomediastinum and subcutaneous emphysema as complica-tions of COVID-19].

Spontaneous pneumothorax, pneumomediastinum and subcutaneous emphysema are serious complications of COVID-19 infection caused by SARS-CoV-2, occurring in approximately 1% of hospitalized patients. The risk increases with the accumulation of risk factors, namely moderate or severe illness, high-flow oxygen therapy and noninvasive ventilation. The pathophysiology may be contributed to by patient self-inflicted lung injury. Hypoxia-induced respiratory effort in patients with pneumonia puts an enormous load on certain parts of their lungs, leading to subsequent progression of lung tissue damage. These complications start with destruction of the alveolar membrane, accompanied by emergence of a pulmonary bulla. Rupture of the bulla results in air leaking to the pleural space (pneumothorax). In the case of pneumomediastinum, the air spreads within the peribronchial interstitium along the airways to the mediastinum and subcutaneous tissues (Macklin effect). While pneumomediastinum and subcutaneous emphysema resolve spontaneously in most cases, pneumothorax treatment depends on its magnitude. While small pneumothorax may be managed conservatively, large pneumothorax usually requires active treatment with an acute chest drain; the latter is also associated with worse prognosis and a higher chance of death. We report air-leak complications in nine COVID-19 patients, of whom seven had spontaneous pneumothorax and four of them died. Three patients developed spontaneous pneumomediastinum together with subcutaneous emphysema, with two of them surviving. One patient with combination of pneumothorax, pneumomediastinum and subcutaneous emphysema died. These complications may accompany moderate or severe COVID-19-associated pneumonia, mostly the late phase of the disease. They should be considered when patients complain of sudden chest or back pain or worsening respiratory insufficiency.