Trauma to the heart occurs in association with either blunt thoracic or penetrating injuries to the chest wall. Tears in the great vessels and many cardiac insults, such as acute cardiac rupture or valvular regurgitation, are often incompatible with life and the patient dies prior to or shortly after arrival at the emergency department (ED).1 In viable patients with more slowly developing problems, an aggressive plan is essential to detect and manage potentially treatable injuries.
The quintessential principle in cardiac ultrasound for all trauma patients, particularly those with chest trauma and potential cardiac injury, is early detection of blood (or blood clot) in the pericardium. The observation of Beck's triad—elevated jugular (central) venous pressure, muffled heart sounds, and hypotension—should always prompt the clinician to further evaluate the heart and pericardial space. However, these textbook physical examination findings are often absent and may occur very late in the course of traumatic cardiac injury.2 Net circulating volume status will affect the clinician's ability to detect the hemodynamic changes typically associated with cardiac trauma. Patients who have sustained multiple traumatic injuries with hemorrhage may have such a profoundly reduced intravascular volume that central venous pressure remains low despite devastating injuries like cardiac rupture with worsening tamponade. Furthermore, because of advances in prehospital emergency care, some patients may arrive in the ED with potentially life-threatening thoracic wounds and yet be relatively asymptomatic.3 The integration of bedside cardiac ultrasound into the early portion of the trauma assessment of patients with multiple traumatic injuries, and particularly those with chest trauma, is important.
Focused abdominal sonography in trauma (FAST) has become a standard diagnostic component during the early evaluation phase of trauma patients (see Chapter 28). First described by Rozycki et al.,4 this examination intentionally has limited goals that allow the physician to make rapid decisions, identify life-threatening disorders, and expedite definitive operative interventions. A 3.5-MHz transducer is placed in the pericardial, right upper quadrant, left upper quadrant, and pelvic regions to evaluate for the presence of free fluid. The FAST examination is noninvasive, can be accomplished rapidly, and can be carried out with handheld or highly portable equipment. It is easily incorporated into the primary or secondary survey of trauma patients. Unlike more invasive procedures, serial FAST examinations can be performed to detect evolving injuries (i.e., accumulation of blood in the pericardium) or to reassess a patient when there are significant hemodynamic changes.
The FAST examination is included in both the 1° and 2° patient surveys outlined in Advanced Trauma Life Support (ATLS) guidelines.5 Under “C” of the “ABCs” of the ATLS 1° survey, the physician is advised to “consider the diagnosis of cardiac tamponade” and urged to rapidly perform the FAST examination (particularly the pericardial view) for patients “with shock that is unresponsive to volume, particularly with penetrating chest trauma” as this “may confirm the diagnosis” (Figure 18.1). Most surgeons would argue that patients with ...