Several case reports suggest that penetrating thoracic cage fractures are an important cause for hemopericardium and cardiac tamponade following blunt trauma. However, the prevalence of this mechanism of injury is not fully known, and considering this association may provide a better understanding of the utility of cardiac component of the FAST (Focused Assessment with Sonography for Trauma).

To determine the association of thoracic cage fractures and pericardial effusion in patients with blunt trauma.

We performed a retrospective, multicenter cohort study using the Trauma Quality Improvement Program (TQIP) database (2015–2017) of adults ≥18 years of age whose mechanism of injury was either a fall or motor vehicle accident. Thoracic cage fractures were defined as any rib or sternum fracture. The primary outcome was the presence of pericardial effusion. Confounding variables were accounted for using multivariable logistic regression.

We included 1,673,704 patients in the study; 226,896 (14%) patients had at least one thoracic cage fracture. A pericardial effusion was present in 4923 (0.3%) patients. When a thoracic cage fracture was present, the odds of having a pericardial effusion was significantly higher (adjusted Odds Ratio [aOR] 6.5 [95% CI: 6.1–7.0]). Patients with left and right-sided rib fractures had similar odds of a pericardial effusion (aOR 1.2 [95% CI 1.04–1.4]). Sternal fractures carried the highest odds of having a pericardial effusion (aOR 11.1 [9.9–12.3]).

Thoracic cage fractures secondary to blunt trauma represent a significant independent risk factor for the development of a pericardial effusion. Our findings lend support for the mechanism of bony injuries causing penetrating cardiac trauma. Given these findings, and the fact that many thoracic cage fractures are detected after the initial evaluation, we support maintaining the cardiac view in the FAST examination for all blunt trauma patients.