Cardiac tamponade

A 25-year-old man requires urgent assessment in the emergency department. Recently admitted following a fall of 20mwhile climbing, he has suddenly become hypotensive (BP 55/30 mmHg), hypoxaemic (SpO2 88% on 15 L/min O2 via a non-rebreathe mask) and tachycardic (HR 160 bpm) having been cardiovascularly stable with good saturations  on admission 60 minutes earlier. He has sustained multiple bilateral rib fractures, a sternal fracture, bilateral fractured scapulae and a mid-shaft femoral fracture but no pelvic fracture. Auscultation of his lung fields reveals bilateral air entry, his trachea is midline, his abdomen is soft and non-distended and there has been no response to administration of 3000mL of crystalloid. Which of the following is the MOST LIKELY diagnosis to explain the sudden deterioration?

a) Blood loss secondary to multiple fractures

b) Cardiac tamponade

c) Severe, bilateral pulmonary contusions

d) Tension pneumothorax

e) Liver laceration

Answer: b

Explanation

This is a challenging case but, although rare, one should consider a traumatic cardiac

tamponade as a possible cause especially in the presence of a fractured sternum. The

classic triad (Beck’s triad) of muffled heart sounds, elevated JVP and hypotension may

be difficult signs to elicit in the emergency department so echocardiography may be

invaluable in this situation. The other four options are all possibilities but elements of

the history make them less likely. It would be unusual to have equal air entry and a

midline trachea in a tension pneumothorax and one would expect some sort of

response to fluid if multiple fractures were the cause, especially if the pelvis is intact.

Significant intra-abdominal pathology would usually manifest some signs and significant

bilateral pulmonary contusions would be unlikely to cause such profound hypotension

so soon after injury.