Frequency and Risk Factors for Spontaneous Pneumomediastinum in COVID-19 Patients

Extracorporeal membrane oxygenation versus invasive ventilation in patients with COVID-19 acute respiratory distress syndrome and pneumomediastinum: A cohort trial

BACKGROUND

Patients with severe respiratory failure due to COVID-19 who are not under mechanical ventilation may develop severe hypoxemia when complicated with spontaneous pneumomediastinum (PM). These patients may be harmed by invasive ventilation. Alternatively, veno-venous (V-V) extracorporeal membrane oxygenation (ECMO) may be applied. We report on the efficacy of V-V ECMO and invasive ventilation as initial advanced respiratory support in patients with COVID-19 and acute respiratory failure due to spontaneous PM.

METHODS

This was a retrospective cohort study performed between March 2020 and January 2022. Enrolled patients had COVID-19 and acute respiratory failure due to spontaneous PM and were not invasively ventilated. Patients were treated in the intensive care unit (ICU) with invasive ventilation (invasive ventilation group) or V-V ECMO support (V-V ECMO group) as the main therapeutic option. The primary outcomes were mortality and ICU discharge at 90 days after ICU admission.

RESULTS

Twenty-two patients were included in this study (invasive ventilation group: 13 [59%]; V-V ECMO group: 9 [41%]). The V-V ECMO strategy was significantly associated with lower mortality (hazard ratio [HR] 0.33 [95% CI 0.12-0.97], p = 0.04). Five (38%) patients in the V-V ECMO group were intubated and eight (89%) patients in the invasive ventilation group required V-V ECMO support within 30 days from ICU admission. Three (33%) patients in the V-V ECMO group were discharged from ICU within 90 days compared to one (8%) patient in the invasive ventilation group (HR 4.71 [95% CI 0.48-45.3], p = 0.18).

CONCLUSIONS

Preliminary data suggest that V-V ECMO without invasive ventilation may improve survival in COVID-19-related acute respiratory failure due to spontaneous PM. The study's retrospective design and limited sample size underscore the necessity for additional investigation and warrant caution.

Severe SARS-CoV-2 Pneumonia and Pneumomediastinum/Pneumothorax: A Prospective Observational Study in an Intermediate Respiratory Care Unit

INTRODUCTION

The occurrence of pneumomediastinum (PM) and/or pneumothorax (PTX) in patients with severe pneumonia due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was evaluated.

METHODS

This was a prospective observational study conducted in patients admitted to the intermediate respiratory care unit (IRCU) of a COVID-19 monographic hospital in Madrid (Spain) between December 14, 2020 and September 28, 2021. All patients had a diagnosis of severe SARS-CoV-2 pneumonia and required noninvasive respiratory support (NIRS): high-flow nasal cannula (HFNC), continuous positive airway pressure (CPAP), and bilevel positive airway pressure (BiPAP). The incidences of PM and/or PTX, overall and by NIRS, and their impact on the probabilities of invasive mechanical ventilation (IMV) and death were studied.

RESULTS

A total of 1306 patients were included. 4.3% (56/1306) developed PM/PTX, 3.8% (50/1306) PM, 1.6% (21/1306) PTX, and 1.1% (15/1306) PM + PTX. 16.1% (9/56) of patients with PM/PTX had HFNC alone, while 83.9% (47/56) had HFNC + CPAP/BiPAP. In comparison, 41.7% (521/1250) of patients without PM and PTX had HFNC alone (odds ratio [OR] 0.27; 95% confidence interval [95% CI] 0.13-0.55; p < .001), while 58.3% (729/1250) had HFNC + CPAP/BiPAP (OR 3.73; 95% CI 1.81-7.68; p < .001). The probability of needing IMV among patients with PM/PTX was 67.9% (36/53) (OR 7.46; 95% CI 4.12-13.50; p < .001), while it was 22.1% (262/1185) among patients without PM and PTX. Mortality among patients with PM/PTX was 33.9% (19/56) (OR 4.39; 95% CI 2.45-7.85; p < .001), while it was 10.5% (131/1250) among patients without PM and PTX.

CONCLUSIONS

In patients admitted to the IRCU for severe SARS-CoV-2 pneumonia requiring NIRS, incidences of PM/PTX, PM, PTX, and PM + PTX were observed to be 4.3%, 3.8%, 1.6%, and 1.1%, respectively. Most patients with PM/PTX had HFNC + CPAP/BiPAP as the NIRS device, much more frequently than patients without PM and PTX. The probabilities of IMV and death among patients with PM/PTX were 64.3% and 33.9%, respectively, higher than those observed in patients without PM and PTX, which were 21.0% and 10.5%, respectively.

Effects of pulmonary air leak on patients with coronavirus disease 2019 (COVID-19): a systematic review and meta-analysis

BACKGROUND

Coronavirus disease 2019 (COVID-19) has posed increasing challenges to global health systems. We aimed to understand the effects of pulmonary air leak (PAL), including pneumothorax, pneumomediastinum and subcutaneous emphysema, on patients with COVID-19.

METHODS

We searched PubMed, Embase and Web of Science for data and performed a meta-analysis with a random-effects model using Stata 14.0. This meta-analysis was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

Thirty-five articles were included in the meta-analysis. The data came from 14 countries and included 3,047 COVID-19 patients with PAL, 11,3679 COVID-19 patients without PAL and 361 non-COVID-19 patients with PAL. We found that the incidence of PAL was much higher in COVID-19 patients than in non-COVID-19 patients (odds ratio (OR) = 6.13, 95% CI: 2.09-18.00). We found that the group of COVID-19 patients with PAL had a longer hospital stay (standardized mean difference (SMD) = 0.79, 95% CI: 0.27-1.30) and intensive care unit (ICU) stay (SMD = 0.51, 95% CI: 0.19-0.83) and comprised more ICU (OR = 15.16, 95% CI: 6.51-35.29) and mechanical ventilation patients (OR = 5.52, 95% CI: 1.69-17.99); furthermore, the mortality rate was also higher (OR = 2.62, 95% CI: 1.80-3.82).

CONCLUSIONS

Patients with lung injuries caused by COVID-19 may develop PAL. COVID-19 patients with PAL require more medical resources, have more serious conditions and have worse clinical outcomes.

PROSPERO REGISTRATION NUMBER

CRD42022365047.

COVID-19-associated lung weakness (CALW): Systematic review and meta-analysis

OBJECTIVES

To assess mortality and different clinical factors derived from the development of atraumatic pneumothorax (PNX) and/or pneumomediastinum (PNMD) in critically ill patients as a consequence of COVID-19-associated lung weakness (CALW).

DESIGN

Systematic review with meta-analysis.

SETTING

Intensive Care Unit (ICU).

PARTICIPANTS

Original research evaluating patients, with or without the need for protective invasive mechanical ventilation (IMV), with a diagnosis of COVID-19, who developed atraumatic PNX or PNMD on admission or during hospital stay.

INTERVENTIONS

Data of interest were obtained from each article and analyzed and assessed by the Newcastle-Ottawa Scale. The risk of the variables of interest was assessed with data derived from studies including patients who developed atraumatic PNX or PNMD.

MAIN VARIABLES OF INTEREST

Mortality, mean ICU stay and mean PaO2/FiO2 at diagnosis.

RESULTS

Information was collected from 12 longitudinal studies. Data from a total of 4901 patients were included in the meta-analysis. A total of 1629 patients had an episode of atraumatic PNX and 253 patients had an episode of atraumatic PNMD. Despite the finding of significantly strong associations, the great heterogeneity between studies implies that the interpretation of results should be made with caution.

CONCLUSIONS

Mortality among COVID-19 patients was higher in those who developed atraumatic PNX and/or PNMD compared to those who did not. The mean PaO2/FiO2 index was lower in patients who developed atraumatic PNX and/or PNMD. We propose grouping these cases under the term COVID-19-associated lung weakness (CALW).

A Pictorial Essay Describing the CT Imaging Features of COVID-19 Cases throughout the Pandemic with a Special Focus on Lung Manifestations and Extrapulmonary Vascular Abdominal Complications

With the Omicron wave, SARS-CoV-2 infections improved, with less lung involvement and few cases of severe manifestations. In this pictorial review, there is a summary of the pathogenesis with particular focus on the interaction of the immune system and gut and lung axis in both pulmonary and extrapulmonary manifestations of COVID-19 and the computed tomography (CT) imaging features of COVID-19 pneumonia from the beginning of the pandemic, describing the typical features of COVID-19 pneumonia following the Delta variant and the atypical features appearing during the Omicron wave. There is also an outline of the typical features of COVID-19 pneumonia in cases of breakthrough infection, including secondary lung complications such as acute respiratory distress disease (ARDS), pneumomediastinum, pneumothorax, and lung pulmonary thromboembolism, which were more frequent during the first waves of the pandemic. Finally, there is a description of vascular extrapulmonary complications, including both ischemic and hemorrhagic abdominal complications.

Pneumomediastinum in patients with COVID-19 undergoing CT pulmonary angiography: a retrospective cohort study

BACKGROUND

Various complications have been reported in patients with COVID-19 including pneumomediastinum.

METHODS

The primary objective of the study was to determine the incidence of pneumomediastinum in COVID-19 positive patients who underwent CT pulmonary angiography (CTPA). The secondary objectives were to analyse if the incidence of pneumomediastinum changed between March and May 2020 (peak of the first wave in the UK) and January 2021 (peak of the second wave in the UK) and to determine the mortality rate in patients with pneumomediastinum. We undertook an observational, retrospective, single-centre, cohort study of patients with COVID-19 admitted to Northwick Park Hospital.

RESULTS

74 patients in the first wave and 220 patients in the second wave met the study criteria. Two patients during the first wave and eleven patients during the second wave developed pneumomediastinum.

CONCLUSIONS

The incidence of pneumomediastinum changed from 2.7% during the first wave to 5% during the second wave and this change was not statistically significant (p value 0.4057). The difference in mortality rates of patients with pneumomediastinum in both waves of COVID-19 (69.23%) versus patients without pneumomediastinum in both waves of COVID-19 (25.62%) was statistically significant (p value 0.0005). Many patients with pneumomediastinum were ventilated, which could be a confounding factor. When controlling for ventilation, there was no statistically significant difference in the mortality rates of ventilated patients with pneumomediastinum (81.81%) versus ventilated patients without pneumomediastinum (59.30%) (p value 0.14).

"Pneumomediastinum: A marker of severity in Covid-19 disease"

Objective

The goal of this study was to look at the incidence, risk factors, clinical characteristics, and radiological aspects of COVID-19 patients who developed pneumomediastinum and compare these features between those who died and those who survived.

Materials and methods

This retrospective observational study included COVID-19 patients having pneumomediastinum on CT from May 2020 to May 2021 in a COVID-19 care hospital. 1st wave patients were considered between the period of May 2020 to January 2021 and those in the second wave between February 2021 to May 2021. The clinical details were analyzed by a consultant intensivist and CT scans were read by a team of 6 resident radiologists and 5 experienced radiologists. Demographic data, co-morbidities, clinical parameters, hemodynamic markers, radiological involvement and associated complications were analyzed.

Results

During the study period, 10,605 COVID-19 patients were admitted to our hospital of which 5689 underwent CT scan. 66 patients were detected to have pneumomediastinum on CT; 26 of them in the first wave and 40 in the second wave. Out of 66, 28 patients were admitted to ICU, 9 during the first wave and 18 during the second wave. The overall incidence of developing pneumomediastinum was 1.16%. Incidence in the 1st wave was 1.0% and in the 2nd wave was 1.29%. The overall mortality rate in admitted COVID-19 patients was 12.83% while it was 43.9% in COVID-19 patients who developed pneumomediastinum. Incidence of pneumomediastinum and pneumothorax was high in patients with extensive parenchymal involvement. 59/66 (89%) cases of pneumomediastinum had severe CT score on imaging.

Conclusion

We conclude that pneumomediastinum is a marker of poor prognosis. Timely diagnosis of interstitial emphysema or pneumomediastinum will aid in planning early protective ventilation strategies and timely intervention of complications.

Pneumomediastinum in the COVID-19 era: to drain or not to drain?

Pneumomediastinum (PNM) is a rare clinical finding, usually with a benign course, which is managed conservatively in the majority of cases. However, during the COVID-19 pandemic, an increased incidence of PNM has been observed. Several reports of PNM cases in COVID-19 have been reported in the literature and were managed either conservatively or surgically. In this study, we present our institutional experience of COVID-19 associated PNM, propose a management algorithm, and review the current literature. In total, 43 Case Series were identified, including a total of 747 patients, of whom 374/747 (50.1%) were intubated at the time of diagnosis, 168/747 (22.5%) underwent surgical drain insertion at admission, 562/747 (75.2%) received conservative treatment (observation or mechanical ventilation. Inpatient mortality was 51.8% (387/747), while 45.1% of the population recovered and/or was discharged (337/747). In conclusion, with increased incidence of PNM in COVID-19 patients reported in the literature, it is still difficult to assign a true causal relationship between PNM and mortality. We can, however, see that PMN plays an important role in disease prognosis.  Due to increased complexity, high mortality, and associated complications, conservative management may not be sufficient, and a surgical approach is needed.

A Rare Complication of Pneumopericardium, Spontaneous Pneumothorax, and Subcutaneous Emphysema in a COVID-19 Pneumonia Patient Treated With High Flow Nasal Cannula

Spontaneous pneumomediastinum (SPM), unrelated to mechanical ventilation, has been newly described as a complication of patients with coronavirus disease (COVID-19) pneumonia without the associated risk factors. The main objective of presenting this case is to highlight a rare but important complication among patients with COVID-19 pneumonia treated only with a high-flow nasal cannula (HFNC). We aim to study the possible underlying pathophysiology of this phenomenon.

Pulmonary barotrauma in COVID-19: A systematic review and meta-analysis

BACKGROUND

An ever-increasing number of studies have reported an increased incidence of spontaneous pulmonary barotrauma such as pneumothorax, pneumomediastinum, and subcutaneous emphysema in patients with COVID-19. We conducted this systematic review and meta-analysis to assess the value and significance of the available data.

METHODS

A thorough systematic search was conducted to identify studies of barotrauma in hospitalized patients with COVID-19. Data analysis of case reports was done using a statistical package for the social sciences (SPSS) version 22, and meta-analysis was performed using CMA-3.

RESULTS

We identified a total of 4488 studies after thorough database searching.118 case reports and series, and 15 observational studies were included in the qualitative analysis. Fifteen studies were included in the quantitative analysis. The observational studies reported barotrauma in 4.2% (2.4-7.3%) among hospitalized patients; 15.6% (11-21.8%) among critically ill patients; and 18.4% (13-25.3%) in patients receiving invasive mechanical ventilation, showing a linear relationship of barotrauma with the severity of the disease. In addition, barotrauma was associated with a longer length of hospital stay, more extended ICU stay, and higher in-hospital mortality. Also, a slightly higher odds of barotrauma was seen in COVID-19 ARDS compared with non-COVID-19 ARDS.

CONCLUSION

COVID-19 pneumonia is associated with a higher incidence of barotrauma. It presents unique challenges for invasive and non-invasive ventilation management. Further studies are required to unravel the underlying pathophysiology and develop safer management strategies.