A study on the evaluation of pneumothorax by imaging methods in patients presenting to the emergency department for blunt thoracic trauma.

BACKGROUND Pneumothorax (PNX) is the collection of air between parietal and visceral pleura, and collapsed lung develops as a complication of the trapped air. PNX is likely to develop spontaneously in people with risk factors. However, it is mostly seen with blunt or penetrating trauma. Diagnosis is generally confirmed by chest radiography [posteroanterior chest radiography (PACR)]. Chest ultrasound (US) is also a promising technique for the detection of PNX in trauma patients. There is not much literature on the evaluation of blunt thoracic trauma (BTT) and pneumothorax (PNX) in the emergency department (ED). The aim of this study was to investigate the effectiveness of chest US for the diagnosis of PNX in patients presenting to ED with BTT. METHODS This study was carried out for a period of nine months in the ED of a university hospital. The chest US of patients was performed by emergency physicians trained in the field. The results were compared with anteroposterior chest radiography and/or CT scan of the chest. The APCR and chest CT results were evaluated by a radiology specialist blind to US findings. The evaluation of the radiology specialist was taken as the gold standard for diagnosis by imaging methods. Clinical follow-up was taken into consideration for the diagnosis of PNX in patients on whom CT scan was not performed. RESULTS Chest US was performed on all two hundred and twelve patients (144 female and 68 male patients; mean age 45.8) who participated in this study. The supine APCR was performed on two hundred and ten (99%) patients and chest CT was performed on one hundred and twenty (56.6%). Out of the twenty-five (11.8%) diagnosed cases of PNX, 22 (88%) were diagnosed by chest US and 8 were diagnosed by APCR. For the detection of PNX, compared to clinical follow-up and chest CT, the sensitivity of chest US was 88%, specificity 99.5%, positive predictive value 95.7% and negative predictive value 98.4%. CONCLUSION Chest US has not superseded supine and standing chest radiography for PNX diagnosis yet in many healthcare centers, but it is performed by emergency physicians and it is an effective and important method for early and bedside diagnosis of PNX.