The clinical course of pneumomediastinum in patients with SARS-CoV-2 before invasive mechanical ventilation.

Pneumomediastinum and pneumothorax are recognised complications encountered in COVID-19 before or during invasive mechanical ventilation (IMV). The clinical course of patients developing pneumomediastinum before IMV is yet to be evaluated.Four-thousand, one-hundred and thirty-one patients hospitalised with COVID-19 over a 12-month period were retrospectively reviewed to evaluate for incidence, clinical characteristics and outcomes. A subgroup analysis was done to identify any clinical traits between survivors and non-survivors. The overall incidence of pneumomediastinum prior to IMV was 0.92% (n=38) and was seen at admission or during non-invasive respiratory support. Thirty-seven per cent had associated pneumothorax most commonly unilateral (right side). The median (interquartile range (IQR)) duration from admission to developing pneumomediastinum was 7 days (3-11) and complete resolution was seen in 53% of patients; median (IQR) duration to resolution was 8 days (4-17). The in-hospital mortality associated with pneumomediastinum in patients with SARS-CoV-2 (PneumoCoV) was 55%. Increasing age (68 ± 12 years vs 56 ± 14 years; p=0.01), higher body mass index (31 ± 5 kg/m vs 28 ± 5 kg/m; p=0.04), lack of resolution of pneumomediastinum (67% vs 24%; p=0.01; odds ratio (OR) 6.5; 95% confidence interval (CI) 1.5-27.5), presence of concurrent pneumothorax (65% vs 14%; p=0.002; OR 11; 95% CI 2.2-53.1) and elevated procalcitonin levels (>0.5 ng/mL; 81% vs 41%; p=0.01; OR 6; 95% CI 1.4-26) were significant features in those who did not survive.The incidence of PneumoCoV, despite being low, is associated with increased mortality. It is a hallmark of moderate to severe disease with multifaceted contributory factors. Both demographic and clinical factors predict survival.