What is the most likely condition in a patient with a history of chest trauma, anterior chest wall hematoma, and pulsus paradoxus (exaggerated decrease in blood pressure during inspiration)?

Cardiac Tamponade

The most likely diagnosis is cardiac tamponade (Option D), as this patient presents with the classic triad of chest trauma, anterior chest wall hematoma suggesting blunt cardiac injury, and pulsus paradoxus (a 25 mmHg drop in systolic blood pressure from expiration to inspiration, which far exceeds the diagnostic threshold of >10 mmHg). 1

Clinical Reasoning

Why Cardiac Tamponade is the Answer

Pulsus paradoxus is the pathognomonic finding that clinches this diagnosis. The patient demonstrates:

• Systolic BP drop of 25 mmHg during inspiration (135 mmHg at end-expiration to 110 mmHg at end-inspiration) 1
• This exceeds the diagnostic threshold of >10 mmHg that defines pulsus paradoxus 1, 2
• Likelihood ratio of 3.3 for tamponade when pulsus paradoxus >10 mmHg is present in a patient with suspected pericardial effusion 2

Mechanism in This Patient

The blunt chest trauma from hitting the steering wheel likely caused hemopericardium (blood accumulation in the pericardial space), leading to rapid-onset tamponade. 1

• Traumatic hemopericardium can cause tamponade even with small fluid volumes when accumulation is rapid, unlike slow-accumulating malignant effusions 1
• The pulsus paradoxus occurs due to exaggerated ventricular interdependence: during inspiration, increased venous return expands the right ventricle, which shifts the septum leftward within the fixed pericardial space, reducing left ventricular filling and stroke volume 1
• This translates to the inspiratory decrease in systemic blood pressure observed clinically 1, 3

Why Other Options Are Incorrect

Aortic Insufficiency (Option A)

• Would cause widened pulse pressure (increased difference between systolic and diastolic pressures), not the narrowing seen here 1
• This patient's diastolic pressure actually increases slightly with inspiration (90 to 92 mmHg), inconsistent with aortic insufficiency

Cardiogenic Shock (Option B)

• While tamponade can progress to cardiogenic shock, the defining feature here is pulsus paradoxus, which is specific to tamponade physiology 1
• Cardiogenic shock from myocardial contusion would not produce this exaggerated respiratory blood pressure variation 1

Left Ventricular Failure (Option C)

• Does not produce pulsus paradoxus 1
• Would typically present with pulmonary edema findings rather than isolated pulsus paradoxus

Immediate Management Algorithm

This is a life-threatening emergency requiring urgent intervention: 1

1. Perform immediate bedside echocardiography to confirm tamponade and assess hemodynamic impact 1, 4

   • Look for: right atrial collapse (most sensitive), right ventricular diastolic collapse (more specific), IVC plethora, respiratory variation >25% in mitral inflow 1

2. Proceed directly to urgent pericardiocentesis or cardiac surgery without delay in this unstable patient 1, 4

   • Use echocardiographic or fluoroscopic guidance for needle pericardiocentesis 1
   • Surgical approach is preferred for traumatic hemopericardium due to risk of ongoing bleeding 1

3. Temporizing measures while preparing for drainage: 4

   • Administer intravenous fluids to maintain preload 4
   • Avoid vasodilators and diuretics - these are contraindicated in tamponade 1, 4

Critical Pitfalls to Avoid

• Do not delay drainage waiting for additional testing - tamponade is a clinical diagnosis confirmed by echo, and this patient meets criteria 1, 4
• Recognize that traumatic tamponade can occur with relatively small effusions when blood accumulates rapidly 1
• Be aware that pulsus paradoxus may be absent in tamponade with coexisting atrial septal defect, severe aortic regurgitation, or pulmonary artery obstruction 4, 5
• The sensitivity of pulsus paradoxus for tamponade is 82%, meaning its presence is highly suggestive but its absence does not exclude the diagnosis 2