Screening for occult penetrating cardiac injuries.

OBJECTIVE: To determine the sensitivity of emergency department ultrasonography (US) in the diagnosis of occult cardiac injuries.

BACKGROUND: Internationally, US has become the investigation of choice in screening patients for a possible cardiac injury after penetrating chest trauma by detecting blood in the pericardial sac.

METHODS: Patients presenting with a penetrating chest wound and a possible cardiac injury to the Groote Schuur Hospital Trauma Centre between October 2001 and February 2009 were prospectively evaluated. All patients were hemodynamically stable, had no indication for emergency surgery, and had an US scan followed by subxiphoid pericardial window exploration.

RESULTS: There were a total of 172 patients (median age = 26 years; range, 11-65 years). The mechanism of injury was stab wounds in 166 (96%) and gunshot wounds in 6. The sensitivity of US in detecting hemopericardium was 86.7%, with a positive predictive value of 77%. There were 18 false-negatives. Eleven of these false-negatives had an associated hemothorax and 6 had pneumopericardium. A single patient had 2 negative US examinations and returned with delayed cardiac tamponade.

CONCLUSIONS: The sensitivity of US to detect hemopericardium in stable patients was only 86.7%. The 2 main factors that limit the screening are the presence of a hemothorax and air in the pericardial sac. A new regimen for screening of occult injuries to make allowance for this is proposed.