Comparison of occult pneumothorax and pneumothorax cases in thoracic trauma: A descriptive, cross-sectional study

Background: The emergency department usually takes a supine posteroanterior (PA) chest X-ray imaging in trauma patients. In some cases, pneumothorax is not seen in the chest X-ray because of the patient's position. These cases are called occult pneumothorax. Misdiagnosis of occult pneumothorax in the emergency department may lead to complications such as tension pneumothorax. This study aimed to update patients’ features with occult pneumothorax due to blunt or penetrating trauma. Methods: In this study, data of 615 thoracic trauma patients admitted to the emergency department between January 2008 and December 2010 were evaluated. In total, 157 patients had undergone both chest X-ray and chest computed tomography and were diagnosed with pneumothorax. Of the 157 patients, 52 were excluded due to some criteria. Data of 105 patient, including their characteristics, trauma types, accompanying traumas, etiology of the chest trauma, chest X-ray findings, and computed chest tomography results were recorded. Data obtained were compared with the results of similar studies conducted in the last 10 years. Chest computed tomography was considered the gold standard for the diagnosis of pneumothorax. Results: The mean patient age was 36.19 ± 14.74 years. Occult pneumothorax was detected in 8 of 105 patients, giving a 7.6% overall incidence of occult pneumothorax. A traffic accident was the most common cause of etiology. All occult pneumothorax cases were caused by blunt trauma, and tube thoracostomy was performed in all of them. No significant differences were found between pneumothorax and occult pneumothorax cases concerning the etiology, accompanied trauma, intervention types, and trauma reasons (p < 0.05). Conclusions: This study supports the incidence of occult pneumothorax reported in the literature. When a patient is admitted with thoracic trauma, a physician should carefully evaluate the patient through supine chest X-ray examination. Only one misdiagnosis in trauma patients can be lead to many unintentional clinical and forensic results.

Is It Time to Modify Definition of Occult Pneumothorax!

Advanced medical technology has enabled diagnosis and management of pneumothorax rapidly and accurately. However, diagnostic dilemma arises when clinical picture does not correlate with normal appearing chest X-ray. We present such a case of an occult pneumothorax diagnosed timely by an ultrasound and promptly addressed. This report compels us to think that should we not redefine occult pneumothorax as “Pneumothorax not suspected in initial chest X-ray or clinical examination but detected on a CT scan or ultrasonography chest”?