Hello and welcome to the Zero to Finals podcast.

My name is Tom and in this episode I'm going to be talking to you about pericardial effusions.

And you can find written notes on this topic at zero tofinals.com slash pericardial effusion

or in the Cardiothoracic surgery section of the Zero to Finals

surgery book. So let's get straight into it. Pericardial effusion is where excess fluid collects

within the pericardial sac. Pericardial effusions can be acute or chronic. They can fill the entire pericardial cavity or they can be localized to a specific section.

The effusion can be made of transudates, which are fluids with a low protein content,

exudates, which are fluids with a high protein content and are associated with inflammation,

blood, pus from infection, or gas, and gas is usually associated with bacterial infections.

Let's talk about the pathophysiology.

There is a membrane that surrounds the heart called the pericardium,

or the pericardial sac. This has two layers with a small amount of fluid in between the layers,

usually less than 50 milliliters, and this fluid provides lubrication. These layers separate the

heart from the rest of the contents of the medestinum. Lubrication between the two layers separate the heart from the rest of the contents of the Mediastinum.

Lubrication between the two layers allows the heart to beat without generating too much friction.

Between the two layers, there is a potential space, which is called the pericardial cavity.

The two layers are usually touching each other, which is why it's only called a potential

space. Pericardial effusion is when the potential space in the pericardial cavity fills with fluid.

This extra fluid in the pericardial cavity creates an inward pressure on the heart, slightly squeezing the heart and making

it more difficult for the heart to expand during diastole when the heart is filling with blood.

Pericardial tamponard, which is also known as cardiac tamponard, is where the pericardial effusion

is large enough to increase the intrapericardial pressure.

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