Occult traumatic hemothorax: when can sleeping dogs lie?

Background Size of traumatic occult hemothorax on admission requiring drainage has not been defined. Computed axial tomography (CAT) may guide drainage criteria. Methods A retrospective review of patients with hemothoraces on CAT was performed. Extrapolating previously described methods of pleural fluid measurement, hemothoraces were quantified using the fluid stripe in the dependent pleural “gutter.” Data included patient age, injury severity, and intervention (thoracentesis or tube thoracostomy). Results Seventy-eight patients with 99 occult hemothoraces met the criteria for study inclusion: 52 hemothoraces qualified as “minimal” and 47 as “moderate/large.” Eight patients (15%) in the minimal group and 31 patients (66%) in the moderate/large group underwent intervention (P < .001). There was no difference in patient age, injury severity, ventilator requirement, or presence of pulmonary contusion. Conclusions CAT in stable blunt-trauma patients can predict which patients with occult hemothorax are likely to undergo intervention. Patients with hemothorax ≥1.5 cm on CAT were 4 times more likely to undergo drainage intervention compared with those having hemothorax <1.5 cm.