Pneumothorax ex vacuo: Three cases of an uncommon entity

Abstract

Pneumothorax is a frequently encountered entity in pulmonary practice and can be primary or secondary. Traumatic and iatrogenic causes also account for a minority of cases presenting to the chest physician. The most common therapeutic intervention done is a tube thoracostomy in all but the mildest of cases. Pneumothorax ex vacuo is a distinctly uncommon entity that differs considerably from the rest of the pneumothorax cases in its pathogenesis, clinical manifestations, radiological findings, and management. Pneumothorax in this entity results from the sucking in of air into the pleural space caused by an exaggerated negative intrapleural pressure, which is most frequently secondary to acute lobar collapse. Symptoms attributable to pneumothorax per se are distinctly mild and the vital aspect of treatment is to relieve the bronchial obstruction. Tube thoracostomy fails to relieve the pneumothorax in such cases and should be avoided. We share three cases of pneumothorax ex vacuo encountered in our institution and alert clinicians of the presentation, radiology, and management of this uncommon condition.

A Case of Pneumothorax Ex Vacuo Associated with COVID-19

“…However, there have been several reports of secondary pneumothorax occurring after the drainage of malignant pleural effusion and radiation. Additionally, tuberculosis, allergic bronchopulmonary aspergillosis, and ventilator-associated pneumonia have been previously reported as etiologies for pneumothorax ex vacuo [2]. Several hypotheses have been proposed for the pathogenesis of pneumothorax ex vacuo [5], one being that underlying pleural diseases restrict the lungs and, in turn, inhibit the re-expansion of the lungs [4].…”

“…In any case, the need for aggressive therapeutic intervention should be determined by patient condition. Even in cases with a poor prognosis such as this one, early improvement of pneumothorax ex vacuo may lead to the early selection of chemotherapy [2].…”

“…Pneumothorax typically requires immediate diagnosis and intervention such as thoracic drainage; if missed, a tension pneumothorax may develop, leading to cardiopulmonary decompensation and death in the most severe cases. On the contrary, small spontaneous pneumothoraces usually heal without treatment and only require observation [2].…”

“…Much controversy exists regarding the treatment of pneumothorax ex vacuo. However, when the cause is malignant pleural effusion, the prognosis is often poor; thus, conservative therapy rather than active surgical intervention is often performed [2].…”