Cardiac Tamponade
The most likely diagnosis is B. Cardiac tamponade. This patient presents with the classic triad of hypotension (88/45 mmHg), tachycardia (110/min), and distended neck veins following blunt chest trauma, with equal bilateral air entry that effectively excludes tension pneumothorax 1, 2.
Diagnostic Reasoning
Why Cardiac Tamponade is Most Likely
Equal air entry bilaterally excludes tension pneumothorax and massive hemothorax, making cardiac tamponade the primary consideration in this hemodynamically unstable post-trauma patient 1, 2.
The clinical triad of hypotension, tachycardia, and elevated jugular venous pressure (distended neck veins) is pathognomonic for cardiac tamponade in the setting of chest trauma 3, 4, 5.
The European Heart Journal guidelines specifically recommend immediate exclusion of pericardial tamponade in patients with hypotension and tachycardia following blunt chest trauma, as this presentation strongly suggests cardiac compression 1, 2.
Tachypnea (30/min) in this context reflects compensatory response to decreased cardiac output rather than primary respiratory pathology, since breath sounds are equal 6, 5.
Why Other Options Are Less Likely
Tension pneumothorax (Option C) is effectively ruled out because the examination confirmed equal air entry on both sides of the chest 1. Tension pneumothorax would present with unilateral absent or decreased breath sounds, hyperresonance to percussion, and tracheal deviation away from the affected side 7.
Simple pneumothorax (Option D) does not cause this degree of hemodynamic instability with hypotension and distended neck veins 7. Simple pneumothorax typically presents with pleuritic chest pain and unilateral decreased breath sounds but maintains hemodynamic stability.
Flail chest (Option A) would present with paradoxical chest wall movement and respiratory distress from mechanical ventilatory impairment, not the combination of hypotension and distended neck veins 7. The primary pathophysiology is respiratory compromise, not obstructive shock.
Immediate Management Algorithm
Step 1: Confirm Diagnosis with Bedside Ultrasound
Perform immediate FAST examination to confirm hemopericardium and guide urgent pericardiocentesis 1, 2.
Key echocardiographic findings confirming tamponade include: diastolic compression of the right ventricle, late diastolic collapse of the right atrium, plethora of the inferior vena cava, and abnormal ventricular septal motion 1, 8, 6.
Step 2: Urgent Intervention
Emergency pericardiocentesis should be performed promptly when cardiac tamponade is suspected based on clinical presentation, even before imaging if the patient is deteriorating 1, 8.
The European Society of Cardiology recommends performing urgent pericardiocentesis with echocardiographic guidance as the primary treatment for impending cardiac tamponade 8.
Place a pericardial drain and leave it in place for 3-5 days to prevent reaccumulation, and send pericardial fluid for analysis 8.
Step 3: Do Not Delay
Intervention should not be delayed for additional imaging if tamponade is clinically suspected and the patient is unstable 1, 2.
The European Heart Journal guidelines state that clinicians should perform standard bedside ultrasound examination immediately in patients with hypotension and tachycardia in isolated chest trauma 1.
Critical Clinical Pitfalls
Do not assume hypotension in isolated chest trauma is solely from hemorrhage—tamponade and tension pneumothorax must be excluded first 2.
Do not rely solely on pulsus paradoxus for diagnosis, as it may be absent in atrial septal defect, severe aortic regurgitation, and regional tamponade 8.
Do not miss the "surgical tamponade" variant, which develops within minutes to hours from bleeding and requires urgent pericardiocentesis, as distinguished from "medical tamponade" that develops over days to weeks 7.
Major complications of pericardiocentesis occur in 1.3-1.6% of cases even with imaging guidance, including coronary artery or cardiac chamber laceration, arrhythmias, and pneumothorax 8.