A trauma patient arrives following a stab wound to the left chest with systolic blood pressure (SBP) 85 mm Hg, which improves slightly with intravenous (IV) fluid resuscitation. Chest X-ray demonstrates clear lung fields. What is the most appropriate next step?A. Computed tomography (CT) scan of the chest
During the circulation section of the primary survey, four lifethreatening injuries must be identified promptly: (1) massive hemothorax, (2) cardiac tamponade, (3) massive hemoperitoneum, and ( 4) mechanically unstable pelvic fractures with bleeding. In this patient hemothorax is unlikely given normal chest X-ray; thus, hemoperitoneum and cardiac tamponade should be suspected. Cardiac tamponade occurs most commonly after penetrating thoracic wounds, although occasionally blunt rupture of the heart, particularly the atrial appendage, is seen. Acutely, < 100 mL of pericardia! blood may cause pericardial tamponade. The classic Beck's triad-dilated neck veins, muffled heart tones, and a decline in arterial pressure is usually not appreciated in the trauma bay because of the noisy environment and associated hypovolemia. Diagnosis is best achieved by bedside ultrasound of the pericardium, which is one of the four views of the FAST examination.