Failure of observation and need for delayed tube thoracostomy in 197 unselected patients with occult pneumothorax: a retrospective study

Introduction: Occult pneumothorax (OPTX) is defined as air in the pleural space that was not suspected on plain chest X-ray but detected on CT. Controversy exists in the management of OPTX, especially in patients who require positive pressure ventilation (PPV). In this study, we investigated the need for tube thoracostomy (TT) in blunt trauma patients with OPTX. Materials and methods: This is a retrospective study of blunt trauma patients of all ages with evidence of OPTX, treated in the Shamir Medical Center Trauma Unit between 2008 and 2017. Two groups were defined. Group I consisted of patients requiring PPV. Group II included patients who did not require PPV. We identified the indication for TT insertion (hemothorax, significant pneumothorax, and enlarging pneumothorax). Necessity for delayed TT insertion due to enlarging pneumothorax was analyzed. Results: Overall 512 patients with traumatic pneumothorax were admitted. 197 (38.5%) had OPTX. Motor vehicle accidents and falls from height accounted for most of the injuries, 47.2 and 42.6%, respectively. Fifty-seven patients required PPV. TT was required in 31 (15.7%) patients. No differences were found between the overall rate of TT insertion between the groups (15.7 vs. 21.1%; p = 0.2) and for delayed insertion of a TT due to an enlarging pneumothorax (25.0 vs. 42.1%; p = 0.45). Conclusion: TT is not indicated in every patient with OPTX even in case of mechanical ventilation.