key: cord-0711309-bsmrhaxj
authors: Pierre, L; Rieu, J; Lemmet, T; Ion, C; Gravier, S; Mohseni-Zadeh, M; Lawson, T; Gerber, V; Martinot, M
title: Characteristic outcomes and risk assessment of pneumothorax in 21 patients with COVID-19
date: 2022-05-07
journal: Infect Dis Now
DOI: 10.1016/j.idnow.2022.05.001
sha: b33ecfc934ea1de383b12a56a7b46e4c73156e0d
doc_id: 711309
cord_uid: bsmrhaxj

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J o u r n a l P r e -p r o o f Furthermore, although the primary mechanism behind PT is related to barotrauma, the exact risk factors are unclear [4] . Hence, we assessed the incidence of PT and compared these patients with controls without PT to identify the main risk factors for PT.

We performed a monocentric retrospective analysis in a French tertiary care hospital, between March 1, 2020 and March 31, 2021. We included all SARS-CoV-2-infected patients who presented with PT, which was defined by the presence of PT on chest X-rays or chest computed tomography (CT) scans. However, we excluded patients with iatrogenic PT (such as direct perforation by catheter insertion, surgery, or pleural drainage). Data on the type of ventilation at PT onset (i.e., spontaneous, oxygen supply, high-flow cannula implantation or noninvasive ventilation [NIV], or MV) and outcomes were collected for each patient. These data were then compared with those of patients without PT who were hospitalized during the same period.

Categorical data were presented as the number of missing values and absolute and relative counts. Continuous variables were compared using the Wilcoxon test, whereas categorical data were compared using the chi-square test or Fisher's exact test.

During the study period, 1,656 patients with laboratory-confirmed SARS-CoV-2 infection 

Barotrauma, primarily during MV, undetected bullous lung disease, and/or diffuse alveolar damage followed by alveolar rupture are all causes of primary PT [5] . Spontaneous PT is caused by repetitive intense episodes of dry cough with a sudden increase in distal airway pressure, causing alveolar rupture and secondary gas leakage in the peribronchovascular pulmonary interstitium. Air can dissect proximally from this area, eventually reaching the mediastinum [6] . For MV-related PT, barotrauma is usually attributable to the rupture of hyperinflated alveoli which is facilitated in patients with SARS-CoV-2-associated acute respiratory distress syndrome (ARDS) by the need for high PEEP to prevent alveolar collapse [7] . PT is thought to be more common in patients with SARS-CoV-2 than in ARDS patients without SARS-CoV-2, suggesting a link with the lung frailty observed during COVID-19 [8] .

The frequency of PT in our study was similar to previous findings [1, 5, 6] . The study by Geraci et al. reported a rate of 7.5%, but their study included iatrogenic cases [9] . PT induced by MV during COVID-19 is more frequently described in the literature, with reported rates of 13%-26% [2, 7] .

When comparing 21 patients with air leakage with 1,631 controls, we found that patients with PT included a significantly higher proportion of men, a finding already reported in most studies analyzed in a meta-analysis by Chong et al. [1] . Moreover, patients with PT had higher CRP and LDH levels at baseline, which could account for the more severe status at baseline and thus a higher level of lung injury, thereby favoring air leakage as previously Page 5 of 11 J o u r n a l P r e -p r o o f described [10] . Patients had a high death rate, especially those on MV, in line with numerous reports highlighting the severity of this complication in these fragile patients [1, 2, 5, 10, 9] .

Although PT can occur in the context of SARS-CoV-2 infections in various ventilation modes, it is most common in serious COVID-19 patients on MV. Male sex, higher baseline CRP, and LDH levels were identified as risk factors in our study. Additionally, mortality was frequent, particularly in patients on MV. Physicians should be aware of the risk of PT when the state of COVID-19 patients deteriorates. 

The incidence, clinical characteristics, and outcomes of pneumothorax in hospitalized COVID-19 patients: A systematic review

Pneumothorax in critically ill patients with COVID-19 infection: Incidence, clinical characteristics and outcomes in a case control multicenter study

Bilateral tension pneumothorax: An unusual complication in a COVID-19 recovered patient

Spectrum of pneumothorax/pneumomediastinum in patients with coronavirus disease 2019

Spontaneous pneumomediastinum, pneumothorax, pneumopericardium and subcutaneous emphysemanot so uncommon complications in patients with COVID-19 pulmonary infection-A series of cases

Spontaneous gas effusions: A rare complication of covid 19

Outcomes of barotrauma in critically ill COVID-19 patients with severe pneumonia

Pneumomediastinum and subcutaneous emphysema in COVID-19: Barotrauma or lung frailty?

Incidence, management, and outcomes of patients with COVID-19 and pneumothorax

Serious complications in COVID-19 ARDS cases: Pneumothorax, pneumomediastinum, subcutaneous emphysema and haemothorax

/L) Missing (%) 1 (5.00%)

Calcium (mmol/L) Missing (%)

/L) Missing (%)

The authors sincerely thank Magali Eyriey, Anne Schieber, Jean-Claude Ongagna, Anais Henric, Mahsa Mohseni Zadeh, Simon Gravier, Damien Kayser for their help in data collection and analysis. The authors thank Christian Kempf for performing the statiscal analysis.