Abstract Tension pneumothorax occurs due to one-way air accumulation within pleural space with mass effect on intrathoracic structures, which can cause rapid hemodynamic instability. While usually an acute medical emergency, here is a case of radiographic tension features with preserved hemodynamics over weeks. A 59-year-old Caucasian male with history of prior smoking, COPD, chronic rheumatoid arthritis on Leflunomide presented for cough, progressive dyspnea and left-sided chest pain ongoing for 3-4 weeks. Vitals were stable on room air aside from sinus tachycardia. Chest X-ray demonstrated a complete left atelectasis with large pneumothorax and rightward mediastinal deviation. A chest tube was placed with improvement of mediastinal deviation. However left atelectasis only partially resolved with persistent air leak, concerning for trapped lung. Antibiotics were initiated and he underwent video-assisted thoracoscopic surgery decortication with mechanical pleurodesis. Pleural studies were consistent with empyema, microbiology positive for MRSA. Postoperative X-ray demonstrated improved lung expansion with resolution of pneumothorax. Pleural biopsy showed acute-on-chronic fibrosing pleurisy with retained BAP-1 expression, consistent with reactive mesothelial proliferation although further pathology evaluation is pending. No CT findings of underlying parenchymal interstitial disease. Discussion ‘Tension pneumothorax’ and ‘subacute’ are rarely used in the same sentence, however here we have a case of a patient going about his daily activities for a month with complete left atelectasis and tension features of unknown duration. Although uncommon, there have been few cases of hemodynamic stability despite tension physiology. As in our patient, these usually present with slowly progressive respiratory failure. These patients seem to improve with chest tube drainage, bypassing the possible risks of needle decompression. It is also difficult to determine if there is some component of chronic pneumothorax ex vacuo secondary to trapped vs entrapped lung with complete atelectasis, given chronically stable hemodynamics. However there was no identified bronchial obstruction to explain the initial lung collapse that could cause a pneumothorax ex vacuo, although that could have cleared from coughing. Also this usually presents with mediastinal shift towards the affected side rather than away and rarely progresses to tension pneumothorax. It is also possible for the underlying trapped lung to cause mimicking of tension features on imaging despite no true tension physiology. A dilemma on if tension pneumothorax caused the lung collapse, or if the lung collapsed and then developed pneumothorax ex vacuo with tension mimicking features secondary to underlying pleural fibrosis. Nevertheless, surgical decortication is warranted in these patients for diagnosis and therapy. This abstract is funded by: None
Ogujiofor et al. (Fri,) studied this question.