Management of traumatic hemothorax: thresholds for chest tube insertion and outcomes; systematic review

Background: Traumatic hemothorax is common after blunt and penetrating chest trauma. With routine CT imaging, small and occult hemothoraces are detected more frequently, creating doubt about when to observe or insert a chest tube and how those choices affect outcomes. We aimed to synthesize original articles on radiologic and clinical thresholds associated with chest tube insertion for traumatic hemothorax and outcomes related to drainage strategy and escalation. Study eligibility: Original clinical studies (randomized or observational) of traumatic hemothorax and hemopneumothorax that reported drainage decisions, thresholds, or outcomes. Methods: our study followed PRISMA guided screening, data extraction, and qualitative synthesis, meta-analysis performed where two or more studies reported comparable outcomes. Primary meta-analysis outcome were needed for VATS after initial drainage in small bore vs large bore drainage strategies. Results: Ten original studies were included, CT based hemothorax depth was associated with drainage decisions, in one cohort >3 cm thickness was drained, while 2 cm was a decision inflection point. In the ventilated trauma patients with occult hemothoraxa and hemopneumothorax, greater CT thickness correlated with tube placement. Delayed hemothorax is uncommon but clinically relevant, readmission for delayed hemothorax after rib fracture observed in 0.26% in a large database study. In meta-analysis, small-bore drainage showed no clear difference in VATS compared with larger bore tubes (RR 0.87, 95% CI 0.47 - 1.60). Conclusion: CT depth is the most reproducible radiologic threshold informing tube insertion decisions, while delayed hemothorax is uncommon but require drainage and operative escalation when it occurs. Small bore drainage strategies did not show a higher VATS requirement in pooled analysis, though articles remains limited and context dependent.