Pediatric emergency medicine trisk 3709 3709

cardiac injury will have neither symptoms nor abnormal physical examination
findings, and therefore a high index of suspicion is required when the mechanism
of injury makes cardiac injury possible.

FIGURE 115.5 Bedside ultrasound showing large pericardial effusion surrounding the heart.

Pericardial tamponade may initially be difficult to diagnose because of
associated injuries obscuring the clinical signs and symptoms. Patients may
present with distant heart sounds, low blood pressure, poor perfusion, a narrow
pulse pressure, or electromechanical dissociation. Pulsus paradoxus, blood
pressure falling more than 10 mm Hg during inspiration, occurs in less than onehalf of patients with pericardial tamponade and should not be relied on to make
the diagnosis.
Management
The evaluation for suspected blunt cardiac injury includes EKG, serum cardiac
troponin, echocardiography, and observation with continuous cardiac monitoring.
A 12-lead EKG may show ST-T-wave changes or arrhythmias. The combination
of a normal EKG and negative troponin is highly sensitive for ruling out
myocardial contusion or other significant blunt cardiac injury. For patients with
an abnormal EKG, elevated cardiac enzymes, or new findings on physical
examination, echocardiography should be performed.