Spontaneous pneumomediastinum, pneumothorax and subcutaneous emphysema in critically ill COVID-19 patients: A systematic review.

Objectives: COVID-19 patients develop Life-threatening complications like pneumomediastinum/pneumothorax and emphysema which might experience prolonged hospital stays and additional costs might be imposed on the patient and the health system. The clinical features and outcomes of mechanically ventilated patients with COVID-19 infection who develop a pneumothorax, pneumomediastinum and subcutaneous emphysema has not been rigorously described or compared to those who do not develop these complications. So a systematic review of studies conducted on this subject was carried out to better manage these complications by investigating the underlying factors in COVID-19 patients. Methods: The search was conducted between early January and late December 2020 in databases including PubMed, Scopus, ProQuest, Embase, Cochrane Library, and Web of Science, using the following keywords and their combinations: COVID-19 Complication, Pneumothorax, Pneumomediastinum, Pneumopericardium, and Subcutaneous Emphysema. The extracted studies were screened separately by two researchers based on the PRISMA statement. After eliminating the duplicate studies, the title, abstract, and full text of the remaining studies were reviewed. Disagreements in the screening and selection of the studies were resolved by consensus or through a third-party opinion. Results: A total of 793 articles were retrieved through the literature search, and 99 studies conducted on a total of 139 patients were finally included The patient mortality was found to have a significant relationship with positive pressure ventilation (P=0.0001). There was no significant relationship between the patients' death and chest tube insertion (P=0.2) or between the interval of time from the onset of symptoms to the diagnosis of pneumothorax (P=0.7). The mean age was higher in the deceased cases, and the mean difference observed was statistically significant (P=0.001). Conclusion: With the expansion of our clinical understanding of COVID-19, recognition of the uncommon complications of COVID-19 especially pneumothorax is crucial. Although in our review we couldn't find a causal relationship between COVID-19 and pneumothorax or association between pneumothorax and death, as it is limited by many variables such as included studies' design, or incomplete outcome data especially more information about the associated risk factors, we recommend performing more well-designed studies to describe the pneumothoraxes' incidence, risk factors, and outcomes in COVID-19 patients.