Incidence and Outcome of Spontaneous Alveolar Air Leak Events in COVID-19 Pneumonia: A Prospective Cohort Study

Abstract

Introduction: Coronavirus Disease 2019 (COVID-19) has increased the burden of hospitalised pneumonia cases and related complications. Spontaneous Pneumothorax (PT) and Pneumomediastinum (PM) have been reported in both spontaneously breathing and ventilated patients with COVID-19 pneumonia. Aim: To determine the incidence and outcomes of spontaneous alveolar air leak events in COVID-19 pneumonia. Materials and Methods: This prospective cohort study was carried out from June 2020 to June 2021 at a tertiary care centre in Western India. All incident cases of alveolar air leaks in COVID-19 pneumonia were included. Clinical and demographic data were collected, and statistical analysis was performed. The Chi-square test or Fisher’s exact test were used to assess the differences in subgroup proportions. Results: A total of 79 patients (63 males and 16 females) experienced spontaneous alveolar air leaks in the form of PT, PM (mediastinal emphysema), or Subcutaneous Emphysema (SE), either isolated or in combination. A total of 58 patients (73.41%) had PT, while 8 patients (10.12%) had isolated PM and 2 patients (2.53%) had isolated SE. Of the total events, 35 (44.30%) occurred in spontaneously breathing patients, among them vigorous coughing was an important precipitating factor. At the time of the incident, 1.27%, 21.52%, and 77.21% of the affected cases belonged to mild, moderate, and severe COVID-19 categories, respectively. Male patients (n-63, 79.74%) in the age group of 30-60 years were predominantly affected. A total of 38 events (48.10%) occurred within two weeks (early) of symptom onset. The PaO2:FiO2 ratio at the time of the alveolar leak showed a significant association with the outcome. Patients with PT had a poorer outcome compared to those with other types of alveolar leaks (p-value<0.005). Major bleeding occurred in 2 (3.33%) of the total 60 Intercostal Drainage (ICD) procedures. Prolonged alveolo-pleural fistula healed spontaneously in four out of five cases. The cumulative incidence for air leak events was 1.55%, and for barotrauma, it was 6.47%. The overall mortality in this cohort was 74.68% (n=59), while it was 29.41% (5 out of 17) in the moderate severity group. Patients with late-onset events had a better outcome (p-value<0.005). Conclusion: In this cohort of COVID-19 pneumonia from Western India, the cumulative incidence of spontaneous alveolar air leaks was 1.55%, predominantly affecting males. The early occurrence of PT in severely hypoxic patients on mechanical ventilator was associated with higher mortality.

Keywords

• barotrauma
• mediastinal emphysema
• pneumothorax
• severe acute respiratory syndrome coronavirus 2