Clinical meaning
Cardiac tamponade results from rapid or excessive accumulation of fluid in the pericardial space, increasing intrapericardial pressure beyond the filling pressure of the cardiac chambers. This compresses the right atrium and ventricle first (due to lower pressures), reducing venous return, stroke volume, and cardiac output. Compensatory mechanisms include tachycardia and peripheral vasoconstriction to maintain blood pressure, but these eventually fail. Equalization of diastolic pressures across all four chambers on hemodynamic monitoring is diagnostic. The nurse must perform rapid cardiovascular assessment, assist with pericardiocentesis, manage hemodynamic monitoring, and administer IV fluids to maintain preload.
Exam relevance
Risk factors: - Cardiac surgery or percutaneous procedures - Pericarditis (viral, bacterial, tuberculous, uremic) - Malignancy with pericardial involvement - Aortic dissection with pericardial rupture - Chest trauma (penetrating or blunt) - Myocardial rupture post-MI - Anticoagulant or thrombolytic therapy - Connective tissue disorders (SLE)