Cardiac Tamponade
This is a rapid revision post for the Final FRCA exam, focusing on the most common CRQ and SOE questions that can get asked.
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This topic was examined in the March 2022 CRQ paper.
Describe the pericardial space
- The pericardial sac has two layers of fibrous tissue surrounding the heart, separated by 15 - 50ml of lubricating pericardial fluid
- These two layers fuse where the great vessels leave the heart into the mediastinum, making the visceral pericardium continuous with the epicardium
What are the functions of the pericardium?
- Physical shock absorber against impact
- Barrier against infection
- Lubricates moving heart inside stationary thorax
- Provides a harness to limit excessive distension of atria and ventricles
- Aids with coronary artery tone by secreting prostaglandins
What fluid shifts occur during cardiac surgery?
- Total body fluid increases up to 30% after cardiopulmonary bypass
However the intravascular volume is often decreased due to:
- Capillary leakage
- Re-distribution
- Polyuria
- Haemorrhage
What are the risk factors for haemorrhage during cardiac surgery?
- Preoperative anticoagulation or antiplatelet therapy
- Bleeding diathesis - inherited or acquired
- Prolonged bypass times
- Re-do surgery
Bleeding is usually described as medical vs surgical.