Diagnostic performance of the cardiac FAST in a high-volume Australian trauma centre

Background: Cardiac injury is uncommon, but it is important to diagnose, in order to prevent subsequent complications. Extended focused assessment with sonography in trauma (eFAST) allows rapid evaluation of the pericardium and thorax. The objective of this study was to describe cardiac injuries presenting to a major trauma centre and the diagnostic performance of eFAST in detecting haemopericardium as well as broader cardiac injuries. Methods: Data of patients with severe injuries and diagnosed cardiac injuries (Injury Severity Score >12 and AIS 2008 codes for cardiac injuries) were extracted from The Alfred Trauma Registry over a four-year period from July 2010 to June 2014. The initial eFAST results were compared to those of the final diagnosis, which were determined after analysing imaging results and intraoperative findings. Results: Thirty patients who were identified with cardiac injuries met the inclusion criteria. Among these, 22 patients sustained injuries under the scope of eFAST, of which a positive eFAST scan in the pericardium was reported in 13 (59%) patients, while nine (41%) patients had a negative scan. This resulted in a sensitivity of 59% (95% CI: 36.7%-78.5%). The sensitivity of detecting any cardiac injuries was lower at 43.3% (95% CI: 26.0-62.3). Conclusions: The low sensitivities of eFAST for detecting cardiac injuries and haemopericardium demonstrate that a negative result cannot be used in isolation to exclude cardiac injuries. A high index of suspicion for cardiac injury remains essential. Adjunct diagnostic modalities are indicated for the diagnosis of cardiac injury following major trauma.