🫀 Chapter 55: Pericardial Tamponade

Beck's Triad · Pulsus Paradoxus · Electrical Alternans · Pericardiocentesis · Obstructive Shock · PEA Arrest

🫀 Pericardial Tamponade: Life-Threatening Compression of the Heart by Pericardial Fluid

📊 Definition & Aetiology
Compression of heart due to fluid accumulation in pericardial space. Causes: post-cardiac surgery (most common in PICU), trauma, malignancy, uraemia, connective tissue disease, TB, viral pericarditis, post-catheterisation.
🩸 Beck's Triad (Classic)
1. Hypotension
2. Muffled heart sounds
3. Raised JVP (jugular venous distension)
Signs of obstructive shock — do not wait for all three to act!
📋 Pulsus Paradoxus
Inspiratory fall in systolic BP >10 mmHg. Caused by exaggerated ventricular interdependence. Sensitive sign of tamponade.
🔬 ECG Findings
• Low QRS voltage
• Electrical alternans (alternating QRS amplitude) — virtually specific for tamponade (due to swinging heart)
🩻 ECHO Findings (Diagnostic)
• Pericardial effusion
• Early diastolic collapse of right atrium (most specific)
• Late diastolic collapse of right ventricle (most sensitive)
• IVC dilatation without respiratory variation
⚙️ Management
• Immediate pericardiocentesis (ECHO-guided)
• Fluid bolus (5-10 mL/kg) while preparing — transient improvement
• Avoid positive pressure ventilation (worsens preload)
• No inotropes (ejection fraction is high; problem is filling, not contractility)
⚠️ Beck's Triad = Cardiac Tamponade until proven otherwise! Hypotension + muffled heart sounds + JVP elevation. Emergency pericardiocentesis is life-saving. Tamponade is a reversible cause of PEA (pulseless electrical activity) arrest.

🩺 Step-by-Step: Pericardial Tamponade Management

1
Recognise tamponade — high index of suspicion
Suspect in: post-cardiac surgery patient with hypotension, any child with shock + raised JVP + muffled heart sounds. Pulsus paradoxus >10 mmHg is highly suggestive.
2
Immediate bedside ECHO (if available)
Confirm pericardial effusion with diastolic RA/RV collapse. Do not delay pericardiocentesis for ECHO if patient is crashing.
3
Fluid bolus (5-10 mL/kg) — temporary measure
Fluids increase preload and can transiently improve cardiac output. Do NOT give large volumes (may worsen tamponade).
4
Avoid positive pressure ventilation if possible
PPV increases intrathoracic pressure, further decreasing preload. Intubate only if absolutely necessary (respiratory failure).
5
Emergency pericardiocentesis — definitive treatment
• ECHO-guided subxiphoid approach preferred
• Insert needle at 15-30° angle aiming toward left shoulder
• Aspirate fluid — dramatic haemodynamic improvement
• Send fluid for analysis (cell count, culture, cytology)
6
If pericardiocentesis fails or clotted haemopericardium → surgical drainage
Thoracotomy or subxiphoid pericardial window. Especially for trauma or post-cardiac surgery (clotted blood).
7
Post-drainage care
Monitor for re-accumulation. Treat underlying cause (antitubercular, anti-inflammatory, etc.). Low-dose aspirin for viral pericarditis.