In a recent study on The Lancet* preprint server, researchers examined the occurrence and patient risk factors involved in pneumothorax in coronavirus disease 2019 (COVID-19) and influenza.
Study: Prevalence and Patient Risk Factors for Pneumothorax in COVID-19 and in Influenza: A Nationwide Comparative Analysis. Image Credit: luchschenF/Shutterstock.com
*Important notice: Preprints with The Lancet / SSRN publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.
Background
Patients with COVID-19 who require mechanical ventilation are at a higher risk for the rare but fatal complication of pneumothorax. Research has shown that hospitalized COVID-19 patients have a 1-2% pneumothorax incidence rate.
The proposed mechanism involves the formation of cysts and decreased lung compliance due to distortion of lung parenchyma and fibrotic changes. Studies have shown that COVID-19 patients who develop pneumothorax have a higher mortality risk.
Nationwide studies on the risk factors, prevalence, and mortality of pneumothorax in COVID-19 patients are scarce, despite numerous case series and reports about its epidemiology among COVID-19 patients.
About the study
The team employed the National Inpatient Sample (NIS) 2020 dataset, a US healthcare database that provides national and regional estimates of inpatient access, care utilization, quality, cost, and outcomes. The study included adult patients aged 18 and older who reported COVID-19 and influenza.
Socioeconomic and comorbidity risk factors were identified in the eligible patient cohort for pneumothorax among COVID-19 patients and its related mortality.
The study’s primary outcomes involved determining the prevalence of pneumothorax among COVID-19 patients and identifying the comorbidity and socioeconomic risk factors associated with these patients. Additionally, secondary outcomes compared COVID-19 patients with and without pneumothorax and compared the risk of pneumothorax in influenza versus COVID-19.
The NIS variables provided information on patients’ demographic characteristics such as age, sex, race, insurance status, and income quartiles according to zip code.
The Elixhauser Comorbidity Index employed in the study included uncomplicated and complicated hypertension, uncomplicated and complicated diabetes, solid cancer, liver disease, chronic pulmonary disorders, and rheumatoid arthritis or collagen vascular diseases.
Results
Approximately 22,545 out of 1,608,980 COVID-19-positive hospitalized patients in 2020 developed pneumothorax. The average age of patients who experienced pneumothorax was 64.5 years. The occurrence of pneumothorax rises with age.
Pneumothorax prevalence was 5.7%, 39.7%, and 52.1% among those aged between 18 to 40 years, 41 to 64 years, and over 65 years. Approximately 66% of the COVID-19 patients from the pneumothorax cohort were males, while 34% were females.
Pneumothorax patients had notably higher hospitalization expenses compared to those without the condition. Patients with pneumothorax incurred an average hospitalization cost of $437,692, significantly higher than the $87,081 average cost incurred by patients without pneumothorax.
Furthermore, patients with pneumothorax had a significantly higher mortality rate of 68.7% compared to 13% in those without pneumothorax.
According to multivariate analysis, the probability of developing pneumothorax is lower in females. Patients with Medicaid and Medicare had lower odds of developing pneumothorax than those with private insurance.
The study also found that African American patients had a lower risk of pneumothorax compared to Caucasians. However, Native Americans, Hispanics, and patients of other races reported a higher risk, with Native Americans having the highest risk.
Certain medical conditions and treatments increase the risk of developing pneumothorax, including a history of stroke, chronic obstructive pulmonary disease (COPD), malnutrition, pulmonary fibrosis, liver disease, bronchiectasis, and positive pressure ventilation methods such as bilevel positive airway pressure (BiPAP), continuous positive airway pressure (CPAP), and high flow nasal cannula (HFNC).
The odds of pneumothorax among intubated and extracorporeal membrane oxygenation (ECMO) patients were very high. The probability of pneumothorax occurrence was low in individuals with substance abuse, nicotine abuse, and obstructive sleep apnea (OSA). Pneumothorax patients also reported a significantly increased risk of cardiac arrest and mortality from any cause.
According to Kaplan-Meier survival estimates, COVID-19 patients with pneumothorax had significantly higher mortality rates than those without pneumothorax, particularly during extended hospital stays.
Notably, the survival probability for patients with pneumothorax decreased as their length of stay rose. While the occurrence of pneumothorax was reduced between March and December 2020, its mortality rate did not change.
Conclusion
COVID-19 can lead to a rare complication called pneumothorax, a serious prognostic marker with a high mortality risk. Pneumothorax can develop due to various risk factors such as sex, age, malnutrition, certain lung conditions, liver disease, and other comorbidities.
Patients with COVID-19 who have risk factors for pneumothorax should be prioritized in preventative strategies.
*Important notice: Preprints with The Lancet / SSRN publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.
