Validation of the 35-mm rule in traumatic pneumothorax in an Asian population

ABSTRACT

Objectives

Thoracic injury crucially threatens human health. Recent studies have suggested using computed tomography (CT) to observe traumatic pneumothorax (PTX). However, cross-ethnic validation is required to overcome potential barriers for the global application of this method. This study aimed to validate the 35-mm rule in traumatic PTX in a Korean population.

Methods

Data from the institutional registry were analyzed, and chest CT images were reviewed. Factors for observation failure were evaluated via logistic regression analysis, and a receiver-operating curve was created to calculate the optimal cutoff value.

Results

In total, 286 participants were included in this study. The average PTX size was 8.2 (3.2–26.5) mm, and 210 of 213 (95.3%) initially observed patients with a PTX size of ≤35 mm successfully completed the safety observation. Multivariate regression analysis revealed that a PTX size of >35 mm is associated with observation failure and suggested a cutoff of 24.5 mm.

Conclusion

Most patients with traumatic PTX of ≤35 mm on CT had undergone successful 4-h observation without thoracostomy. Additionally, PTX of >35 mm was an independent risk factor for observation failure. Considering the lower optimal cutoff value and high failure rates observed in this study, the current guidelines need modifications.

KEYWORDS:

• Thoracic injury
• chest trauma
• traumatic pneumothorax
• trauma center
• South Korea

Declaration of financial/other relationships

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties. Peer reviewers on this manuscript have received an honorarium from Postgraduate Medicine for their review work but have no other relevant financial relationships to disclose.

Author contribution

Conceptualization, data curation, formal analysis, investigation, methodology, software, supervision, validation, visualization, reviewing and updating all data, original draft writing, and final manuscript approving: Woo Young Nho.

Ethics statement

The study was approved by the Institutional Review Board of Kyungpook National University Hospital (No. KNUH 2023-05-009), and individual consent for this retrospective study was waived.

Data availability statement

The datasets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request.

Additional information

Funding

This work was supported by Biomedical Research Institute grant, Kyungpook National University Hospital (2023).