Spontaneous pneumomediastinum: A collaborative sequelae between COVID-19 and self-inflicted lung injury - A case report and literature review

Non-Ventilated Patients with Spontaneous Pneumothorax or Pneumomediastinum Associated with COVID-19: Three-Year Debriefing across Five Pandemic Waves

Spontaneous pneumothorax and pneumomediastinum (SP-SPM) are relatively rare medical conditions that can occur with or independently of COVID-19. We conducted a retrospective analysis of SP-SPM cases presented to the emergency departments (EDs) of two University-affiliated tertiary hospitals from 1 March 2020 to 31 October 2022. A total of 190 patients were identified: 52 were COVID-19 cases, and 138 were non-COVID-19 cases. The primary outcome we were looking for was in-hospital mortality. The secondary outcomes concerned the disease severity assessed by (a) days of hospitalization; (b) required mechanical ventilation (MV); and (c) required intensive care (IC). All were investigated in the context of the five pandemic waves and the patients' age and comorbidities. The pandemic waves had no significant effect on the outcomes of these patients. Logistic regression found age (OR = 1.043; 95%CI 1.002-1.085), COVID-19 (OR = 6.032; 95%CI 1.757-20.712), number of comorbidities (OR = 1.772; 95%CI 1.046-3.001), and ground-glass opacities over 50% (OR = 5.694; 95%CI 1.169-27.746) as significant risk predictors of in-hospital death while controlling for gender, smoking, the pandemic wave, and the extension of SP-SPM. The model proved good prediction performance (Nagelkerke R-square = 0.524) and would hold the same significant predictors for MV and IC.

Prognosis of Spontaneous Pneumothorax/Pneumomediastinum in Coronavirus Disease 2019: The CoBiF Score

Objectives: Pneumothorax and pneumomediastinum are associated with high mortality in invasively ventilated coronavirus disease 2019 (COVID-19) patients; however, the mortality rates among non-intubated patients remain unknown. We aimed to analyze the clinical features of COVID-19-associated pneumothorax/pneumomediastinum in non-intubated patients and identify risk factors for mortality. Methods: We searched PubMed Scopus and Embase from January 2020 to December 2021. We performed a pooled analysis of 151 patients with no invasive mechanical ventilation history from 17 case series and 87 case reports. Subsequently, we developed a novel scoring system to predict in-hospital mortality; the system was further validated in multinational cohorts from ten countries (n = 133). Results: Clinical scenarios included pneumothorax/pneumomediastinum at presentation (n = 68), pneumothorax/pneumomediastinum onset during hospitalization (n = 65), and pneumothorax/pneumomediastinum development after recent COVID-19 treatment (n = 18). Significant differences were not observed in clinical outcomes between patients with pneumomediastinum and pneumothorax (±pneumomediastinum). The overall mortality rate of pneumothorax/pneumomediastinum was 23.2%. Risk factor analysis revealed that comorbidities bilateral pneumothorax and fever at pneumothorax/pneumomediastinum presentation were predictors for mortality. In the new scoring system, i.e., the CoBiF system, the area under the curve which was used to assess the predictability of mortality was 0.887. External validation results were also promising (area under the curve: 0.709). Conclusions: The presence of comorbidity bilateral pneumothorax and fever on presentation are significantly associated with poor prognosis in COVID-19 patients with spontaneous pneumothorax/pneumomediastinum. The CoBiF score can predict mortality in clinical settings as well as simplify the identification and appropriate management of patients at high risk.

Understanding Pneumomediastinum as a Complication in Patients With COVID-19: A Case Series

Pneumomediastinum is a rare complication among non-coronavirus patients but has been published with increased incidence in patients positive for SARS-CoV-2 infection. Most of these studies report patients on mechanical ventilation and an understanding of mechanisms causing this remains limited. We aim to use an increasing occurrence in patients not on mechanical ventilation to further explore mechanisms that predispose patients to pneumomediastinum and to assess characteristics potentially related to poor outcomes. We report a case series of 37 patients diagnosed with COVID-19 and pneumomediastinum at a 2-hospital institution between January 1, 2020 and April 30, 2021. At 28 days after diagnosis of pneumomediastinum, 19 (51.4%) were dead and mortality was significantly higher among those who were older (t = 2.147, P = .039), female (χ2 = 10.431, P = .015), body mass index ≥30 (χ2 = 6.0598, P = .01), intubated (χ2 = 4.937, P = .026), and had pre-existing lung disease (χ2 = 4.081, P = .043). Twenty-three patients (62.2%) were identified to have pneumomediastinum without receiving invasive mechanical ventilation, of which 11 (47.8%) were diagnosed without receiving noninvasive ventilation. The increased diagnosis of pneumomediastinum in patients with COVID-19 while not on mechanical ventilation, in this case series and in comparable studies, may attribute to mechanisms aside from positive pressure ventilation such as patient self-induced lung injury and pulmonary frailty.