What is the most likely diagnosis for a patient involved in a head-on collision, presenting with hypotension, tachycardia, ecchymosis on the anterior chest wall, and distended neck veins, with equal air entry bilaterally and a soft abdomen?

Cardiac Tamponade

The most likely diagnosis is cardiac tamponade (Option A). This patient presents with the classic triad of hypotension (90/60 mmHg), tachycardia (130/min), and distended neck veins following blunt chest trauma with anterior chest wall ecchymosis—a constellation that strongly suggests pericardial tamponade requiring immediate intervention. 1

Clinical Reasoning

The presence of hypotension and tachycardia in isolated chest trauma mandates immediate exclusion of pericardial tamponade and tension pneumothorax/hemothorax before attributing these findings to hemorrhage alone. 1 This patient's clinical presentation systematically points to tamponade:

Key Diagnostic Features Present

• Distended neck veins (elevated jugular venous pressure) occur in 76% of tamponade cases and result from impaired venous return due to pericardial compression 2
• Hypotension with tachycardia represents the hemodynamic compromise from cardiac compression by pericardial fluid 3, 4
• Anterior chest wall ecchymosis indicates significant blunt cardiac trauma from compression of the heart between sternum and spine 1
• Equal air entry bilaterally effectively excludes tension pneumothorax and massive hemothorax 1

Why Not the Other Options

Bilateral tension pneumothorax (Option D) is excluded because this patient has equal air entry bilaterally—tension pneumothorax would cause absent breath sounds on the affected side(s) and is incompatible with normal bilateral air entry. 5 Additionally, while tension pneumothorax can cause distended neck veins and hypotension, it would present with respiratory distress (this patient has normal respiratory rate of 18/min) and absent breath sounds. 5

Massive hemothorax (Option C) is ruled out by the equal bilateral air entry—a massive hemothorax would cause decreased or absent breath sounds on the affected side and dullness to percussion, neither of which are present. 1

Cardiac contusion (Option B) is less likely because while it can occur with blunt chest trauma, it typically does not present with the acute hemodynamic compromise and distended neck veins seen here. 1, 6 Cardiac contusion ranges from clinically silent arrhythmias to wall motion abnormalities, but the acute presentation with Beck's triad components (hypotension, distended neck veins, and muffled heart sounds—though the latter is not mentioned here) points more specifically to tamponade. 1

Immediate Management Algorithm

Perform bedside FAST (Focused Assessment with Sonography for Trauma) examination immediately to confirm hemopericardium and guide urgent pericardiocentesis. 1, 6 The European Heart Journal guidelines specifically state that clinicians should perform standard bedside ultrasound examination including screening for clinically significant hemopericardium in patients with hypotension and tachycardia in isolated chest trauma. 1

Next Steps After FAST

• If FAST confirms pericardial effusion with tamponade physiology: Proceed immediately to pericardiocentesis under echocardiographic guidance 4
• Emergency pericardiocentesis should be performed promptly when cardiac tamponade is suspected based on clinical presentation even before imaging if the patient is deteriorating 1
• Echocardiographic features confirming tamponade include: diastolic compression of right ventricle, late diastolic collapse of right atrium, plethora of IVC, and abnormal ventricular septal motion 1

Critical Clinical Pearls

Do not delay intervention for additional imaging if tamponade is clinically suspected and the patient is unstable. 6 However, this patient appears relatively stable (talking coherently, respiratory rate 18/min), making bedside FAST the appropriate immediate next step rather than blind pericardiocentesis. 1

Pulsus paradoxus >10 mmHg would increase diagnostic certainty (likelihood ratio 3.3), though its absence does not exclude tamponade. 2 Among patients with cardiac tamponade, 82% have pulsus paradoxus, 77% have tachycardia, and 76% have elevated jugular venous pressure—all features consistent with this presentation. 2

Cardiac tamponade from blunt chest trauma can present immediately or be delayed (even up to 9 weeks post-injury), though acute presentation with hemodynamic compromise as seen here requires immediate recognition and treatment. 7