Traumatic Cardiac Tamponade
A 42-year-old man is brought to the emergency department after a high-speed car crash with chest pain. His airway is patent, breath sounds are equal bilaterally, and his neck veins are distended. Blood pressure is 88/45 mm Hg, heart rate 110 beats/min, and respiratory rate 30 breaths/min. Which of the following is the most likely diagnosis?
- A.Flail chest
- B.Cardiac tamponadeCorrect
- C.Tension pneumothorax
- D.Simple pneumothorax
Explanation
Hypotension with tachycardia and distended neck veins after chest trauma defines obstructive shock, in which something mechanically prevents the heart from filling or ejecting. The two injuries that produce this pattern in a trauma bay are tension pneumothorax and cardiac tamponade, and the lung examination separates them. In tamponade, blood collects within the non-compliant pericardial sac, so ventricular diastolic filling is limited, cardiac output falls, and venous pressure rises, producing hypotension and jugular venous distension. Because the pathology is confined to the pericardium, the lungs are ventilated normally and air entry stays equal on both sides, exactly as described here. A tension pneumothorax would instead give absent or markedly reduced breath sounds with hyperresonance on the affected side and often tracheal deviation, none of which are present. A simple pneumothorax reduces breath sounds on one side but does not cause shock or raised jugular venous pressure. Flail chest produces paradoxical chest wall movement and hypoxia from the underlying pulmonary contusion, not venous distension. Recognizing obstructive shock with equal breath sounds should trigger urgent bedside echocardiography or the pericardial view of the extended FAST, followed by pericardial decompression and operative repair.
Why each option
- A.
- Flail chest causes paradoxical chest wall motion and hypoxia from the associated pulmonary contusion. It does not by itself cause distended neck veins or obstructive shock.
- B.
- Correct. Hypotension, tachycardia, distended neck veins and equal breath sounds after blunt chest trauma is the classic picture of pericardial tamponade.
- C.
- Tension pneumothorax also gives obstructive shock with distended neck veins, but breath sounds would be absent or markedly reduced on the affected side. Equal air entry makes it very unlikely.
- D.
- A simple pneumothorax reduces unilateral breath sounds without causing hypotension or raised venous pressure. It does not explain this degree of shock.
Reference: ATLS Advanced Trauma Life Support, 10th ed., American College of Surgeons, 2018, Thoracic Trauma
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