Think twice before diagnosing tension pneumothorax: a retrospective analysis of pseudotension pneumothorax

Tension pneumothorax (TP) is a clinical emergency that requires immediate treatment. However, there are specific cases that may be misdiagnosed as TP in clinical settings, potentially leading to iatrogenic injury. This study aims to analyze and summary instances of misdiagnosis in order to improve the clinicians' ability to recognize and distinguish pseudotension pneumothorax. Cases misdiagnosed as TP were retrospectively analyzed by literature retrieval, and the related clinical characteristics were summarized. There were 45 cases misdiagnosed as TP, including 27 (60.0%) cases of diaphragmatic hernia (DH), 9 cases of giant pulmonary bullae (GPB), 8 cases of cystic lung lesions (CLLs) and 1 case of pulmonary hydatid cyst (PHC). 77.8% cases occurred in emergency and paediatric departments. Among patients with DH, 92.6% had the condition on the left with a younger onset age, and 85.2% presented with a history of digestive system diseases, surgery, trauma, or digestive system manifestations. The onset of GPB was mild, without haemodynamic abnormalities, and 66.7% patients were male. CLLs were mainly occurred in infants. Among 45 cases, 93.3% were misdiagnosed by chest X-ray, which showed "pseudo-pneumothorax line", with compressed lung displaced centrifugally away from hilum. In DH, the diaphragm appeared indistinct without gastric bubbles, while air-fluid level might be noted. Finally, 66.7% patients were definitely diagnosed by CT scan and others by thoracotomy, thoracic drainage, X-ray after gastric tube insertion, etc Thoracic tube drainage was performed in 91.1% patients, with 24.4% patients draining fluid, and 9.8% patients deteriorated after drainage. 41.5% patients suffered complications, including gastric perforation, hemopneumothorax and subcutaneous emphysema. Except for 1 patient who did not report the treatment and prognosis, all other patients recovered and were discharged after treatment. Distinguishing PTP from TP is clinically challenging. A thorough medical history, detailed clinical features, chest X-ray, ultrasound, CT, and strategic gastric tube insertion can provide important value for differential diagnosis. Clinicians need to think twice before placing a thoracic drainage tube to prevent additional iatrogenic injury.