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. The goal of this study was to analyse and summarize instances of misdiagnosis in order to improve the clinician's ability to recognize and distinguish pseudotension pneumothorax (PTP).

Cases misdiagnosed as TP were retrospectively analysed by literature retrieval, and the related clinical characteristics were summarized.

A total of 45 cases were misdiagnosed as TP, including 27 (60.0%) cases of diaphragmatic hernia (DH), 9 cases of giant pulmonary bullae, 8 cases of cystic lung lesions and 1 case of pulmonary hydatid cyst. A total of 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 giant pulmonary bullae was mild, without haemodynamic abnormalities, and 66.7% of the patients were males. Cystic lung lesions occurred mainly 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, whereas the air-fluid level might be noted. Finally, 66.7% of patients were definitely diagnosed from computed tomography scans and others by thoracotomy, thoracic drainage, X-ray after gastric tube insertion, and so forth. Thoracic tube drainage was performed in 91.1% of patients, with 24.4% of patients draining fluid, and 9.8% of patients deteriorated after drainage. A total of 41.5% of patients suffered complications, including gastric perforation, haemopneumothorax 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, computed tomography and strategic gastric tube insertion can provide important information of value for differential diagnosis. Clinicians need to think twice before placing a thoracic drainage tube to prevent additional iatrogenic injury.