Cardiac tamponade after cardiac surgery — FFICM MCQ

Correct answer: A — Call the cardiac surgical team for urgent re-exploration

The correct answer is A, call the cardiac surgical team for urgent re-exploration. This patient has the classic triad of post-cardiotomy tamponade: rising CVP, narrowing pulse pressure and falling drain output in the context of recent cardiac surgery, confirmed on echo by a small underfilled LV with pericardial clot compressing the right atrium. Post-surgical tamponade is frequently caused by localised clot rather than free fluid, so it can compress a single chamber and cause haemodynamic collapse despite an apparently unimpressive pericardial collection, and it will not resolve with medical measures. Definitive treatment is surgical evacuation of clot via resternotomy, and delay increases the risk of cardiac arrest, so the cardiac surgical team must be summoned immediately while resuscitation continues. Why the other options are wrong: A, alteplase through the mediastinal drain: thrombolytic instillation is not standard practice for tamponade and risks precipitating catastrophic mediastinal or systemic bleeding in a fresh sternotomy patient. B, furosemide infusion: diuresis reduces preload and circulating volume, worsening ventricular filling and cardiac output in a tamponade physiology that is preload dependent. C, increase PEEP to improve venous return: raised intrathoracic pressure further impedes venous return and right heart filling, worsening tamponade physiology rather than improving it. E, pericardiocentesis as definitive treatment: needle drainage is ineffective against localised clot compressing a chamber and is not definitive management after cardiac surgery; it may have a temporising role in extremis but surgical evacuation is required. Key point: falling mediastinal drain output combined with rising CVP and narrowing pulse pressure after cardiac surgery signals drain blockage from clot and tamponade, not improvement, and mandates urgent surgical re-exploration.

Reference: BJA Education, 'Management of cardiac arrest following cardiac surgery' (2018) - notes that absence of tamponade on TTE/TOE should not preclude return to theatre in the deteriorating post-cardiac-surgery patient, as localised clot can cause significant compression despite small volumes; https://pmc.ncbi.nlm.nih.gov/articles/PMC7807979/