What volume of fluid in the pericardial sac can cause significant compression?

The correct response highlights that a volume of approximately 10-15 ml of fluid in the pericardial sac can lead to significant compression of the heart. In instances of pericardial effusion, the pericardial sac may accommodate certain amounts of fluid without immediate clinical effects. However, when fluid accumulation surpasses this threshold, even a relatively small volume can impede cardiac filling and function due to the restrictive nature of the fibrous pericardium.

Fluid volumes exceeding this range can compromise diastolic filling of the heart, leading to increased intrapericardial pressure and potentially resulting in cardiac tamponade. The hemodynamic implications of such compression are substantial, often manifesting as reduced cardiac output and symptomatic hypotension. Understanding this volume threshold is critical for prompt diagnosis and intervention in trauma and critical care settings.