Incidence, Risk Factors and Impact on Outcomes of Pneumothorax in COVID-19 Patients Requiring ICU Level of Care - A Single-Center Retrospective Study

RATIONALE: Pneumothorax (PTX) incidence, risk factors and impact on outcomes in patients with COVID-19 are unknown. We hypothesized that PTX is associated with a higher rate of mortality and is more likely to occur in patients with severe COVID-19 requiring mechanical ventilation (MV) at higher maximal PEEP and with higher levels of markers of inflammation. METHODS: We conducted a retrospective, cohort study of all adult patients (>18 years) with confirmed diagnosed SARS-CoV-19 infection admitted to our medical intensive care units (ICU) between 3/11/2020 and 8/19/2020 at our 2 hospital healthcare system. Exclusion criteria were non-Covid illness resulting in ICU level of care and ICU stay less than 24 hours. Presence or absence of PTX was determined by retrospective review of chest imaging reports. The primary outcome was mortality at discharge. Secondary outcome measures assessed at the p=0.05 level included age, ethnicity, BMI, maximum PEEP on MV and laboratory inflammatory markers (CRP, D-dimer, LDH, Ferritin). RESULTS: 270 patients with COVID-19 were admitted to the ICU. 11 patients were excluded leaving 259 for analysis. PTX was identified in 16 (6.2%). In the entire group, 9 of 16 (56.2%) patients with PTX died in the hospital compared to 68 of 243 (28%) without PTX (p=0.017). There were no significant differences in age, BMI, highest PEEP, or mortality in the subgroup treated with MV. The rate of PTX was significantly lower in the Black population and higher in the Hispanic population (p=0.01). There were no significant differences in the levels of the inflammatory markers for those patients who developed PTX compared to those who did not (CRP p=0.71;D-dimer p=0.11;Ferritin p=0.36;LDH p=0.41). CONCLUSION: PTX occurred in about 6% of COVID-19 patients requiring ICU level of care with most on mechanical ventilation and was significantly associated with a higher rate of mortality for the entire population, but not in the subgroup of patients requiring mechanical ventilation. PTX frequency was significantly lower in the Black population and higher in the Hispanic population. PTX was not associated with higher PEEP values. The absence of an association with PEEP suggests that barotrauma may not be the etiology of pneumothorax in COVID-19. Age, BMI, and the levels of inflammatory markers were not significantly different in these groups.