Management of minimal pneumothorax in penetrating chest trauma: Is observation safe?

BACKGROUND: Traumatic pneumothorax is one of the most common findings encountered after chest trauma and often forces clinicians to quickly decide between tube thoracostomy and observation. Although large pneumothoraces (LP), most often defined radiologically as a pleural gap greater than 2 cm, are routinely managed with chest tube drainage, the management of minimal pneumothoraces (MP) is still a matter of debate. METHODS: In this study, we analyzed 193 consecutive penetrating thoracic trauma patients managed in our center over a five-year period (2020-2025). Patients were classified into minimal pneumothorax and large pneumothorax groups based on computed tomography (CT) findings. Clinical and radiological parameters, Injury Severity Score (ISS), complications, and hospital stay were recorded, and their associations with chest tube placement were assessed. RESULTS: Among the 193 patients, 112 (58%) were in the MP group and 81 (42%) in the LP group. The median age was comparable between groups (30.5 years [interquartile range, IQR: 22.8-39.3] vs. 28 years [IQR: 23-39], p=0.797). Gender distribution was also similar, with males accounting for 93.3% in the MP group and 93.8% in the LP group (p=1.000). Pneumothorax size strongly influenced treatment (p<0.001): chest tube thoracostomy was performed in 95.1% of LP vs. 9.8% of MP cases. Conservative observation was successful in 90.2% of MP patients. LP patients had significantly longer hospital stays (8.29 vs. 4.56 days, p<0.001), higher ICU admission rates (27.2% vs. 5.4%, p<0.001), and higher ISS (21.33 vs. 13.68, p<0.001). Complications were more frequent in LP (24.7% vs. 0.9%, p<0.001), with hemothorax, persistent air leak, and pleural effusion being the most common. Most hemothorax cases were attributed to the initial penetrating trauma, while only a small minority were tube-related. Among patients with LP (>2 cm), four were managed conservatively due to their stable clinical condition, and no mortality occurred in this subgroup. Mortality occurred exclusively in the chest tube group (18/88, 20.5%), with no deaths among observed patients overall (p<0.001). In subgroup analysis, gunshot wounds were associated with a higher need for chest tube even in MP (20.7% vs. 6.0%, p=0.033). CONCLUSION: Our findings indicate that careful observation is a safe option in patients with minimal pneumothoraces, while large pneumothoraces generally necessitate invasive treatment and are associated with worse outcomes. Our results are consistent with previous reports in the international literature.