An occult pneumothorax is a pneumothorax not visualized on a supine chest X-ray (CXR) but detected on computed tomography (CT) scanning. With increasing CT use for trauma, more occult pneumothoraces may be detected. Management of occult pneumothorax remains controversial, especially for patients undergoing mechanical ventilation. This study aimed to identify the incidence of occult pneumothorax and describe its management among Hong Kong Chinese trauma patients.
Analysis of prospectively collected trauma registry data. Consecutive significantly injured trauma patients admitted through the emergency department (ED) suffering from blunt chest trauma who underwent thoracic computed tomography (TCT) between in calendar years 2007 and 2008 were included. An occult pneumothorax was defined as the identification (by a specialist radiologist) of a pneumothorax on TCT that had not been previously detected on supine CXR.
119 significantly injured patients were included. 56 patients had a pneumothorax on CXR and a further 36 patients had at least one occult pneumothorax [occult pneumothorax incidence 30% (36/119)]. Bilateral occult pneumothoraces were present in 8/36 patients, so the total number of occult pneumothoraces was 44. Tube thoracostomy was performed for 8/44 occult pneumothoraces, all of which were mechanically ventilated in the ED. The remaining 36 occult pneumothoraces were managed expectantly. No patients in the expectant group had progression of the pneumothoraces, even though 8 patients required subsequent ventilation in the operating room for extrathoracic surgery.
The incidence of occult pneumothorax in Hong Kong Chinese after blunt chest trauma was higher than that in Caucasians. Most occult pneumothoraces were managed expectantly without significant complications; no pneumothorax progressed even though some patients were mechanically ventilated.
The traditional practice of performing tube thoracostomy for all occult pneumothoraces which will be mechanically ventilated may not be necessary. Expectant management may be a viable and effective treatment option. Since tube thoracostomy is not without complication, it may be possible to extend the concept of expectant management to those who require mechanical ventilation in the trauma room.
Colin Graham, No Financial Disclosure Information; No Product/Research Disclosure Information