Predictors of retained hemothorax in patients with penetrating thoracic trauma

Tube thoracostomy is the most common procedure for thoracic trauma. Retained hemothorax (RH) is a frequent complication after penetrating thoracic trauma (PTT), associated with empyema, fibrothorax, prolonged stays, and higher costs. Although several risk factors have been proposed, evidence remains inconsistent. We aimed to prospectively identify predictors of RH in patients with PTT.

We conducted a prospective study of 324 consecutive patients with hemothorax secondary to PTT who underwent chest tube drainage at a Level I trauma center between September 2016 and January 2018. Consecutive patients aged ≥14 years with penetrating chest trauma-related hemothorax treated with chest tube thoracostomy from September 2016 to January 2018 were included. Exclusion criteria were initial thoracotomy, isolated pneumothorax, or death within 48 h. Clinical and surgical data were collected. RH was defined as blood in the pleural cavity confirmed on imaging, that required surgical intervention. Non-normally distributed continuous variables were described as median (Q₁, Q₃) and compared using the Wilcoxon-Mann-Whitney test. Categorical variables were compared by Chi-square or Fisher's exact test. Multivariable logistic regression with purposeful selection was used, with results reported as odd ratios (OR) (95% confidence interval (CI)).

RH occurred in 41 (12.6%) patients. The final regression model indicated that total drainage greater than 1000 mL (OR 2.52; 95% CI 1.59 - 3.98) and the requirement of ≥2 chest tubes (OR 4.62; 95% CI 1.68 - 12.94) were independent risk factors for RH. Patients who underwent laparotomy were at lower risk of developing RH (OR 0.07; 95% CI 0.01 - 0.58). Injury severity and delay in chest tube insertion were not independent predictors of RH.

The incidence of RH after PTT was similar to that reported in the literature. Increased total drainage and need for multiple chest tubes were independent predictors of RH, whereas concomitant laparotomy was protective, likely due to enhanced drainage conditions. These findings may guide clinical decision-making and identify patients at higher risk for RH.