Pulmonary wedge pressure

Today we're going to make hemodynamics way easier to understand.

By the end of this video, you'll be able to connect preload, afterload, contractility, cardiac output, SBR, CVP, and PAOP to what you're seeing in a hypotensive patient.

Instead of looking at each number by itself, we're going to use them together to figure out whether the main problem is filling, pump function, vascular tone, or oxygen delivery.

My name is Sachi.

If your patient is on high PEEP, some of that pressure is transmitted into the chest and can raise the CVP even when the patient does not have excess circulating volume.

And a CVP of 6 also does not automatically mean the patient needs fluid, right? The ventricle may already be on the flat part of its response curve, or the hypotension may be coming from basodilation rather than inadequate filling.

PAOP, which we also call the wedge pressure, gives us an estimate of left atrial pressure when the catheter position and measurement conditions are right, of course.

It can help us think about left-sided filling pressure, but it still does not directly measure left ventricular volume.

But an elevated pulmonary artery pressure alone does not tell you the mechanism.

For precapillary pulmonary hypertension, you need three things, MPAP greater than 20, pulmonary artery wedge pressure, or PAWP, of 15 or less, and pulmonary vascular resistance, or PVR, greater than two wood units.

If the wedge pressure is greater than 15, we're dealing with postcapillary pulmonary hypertension.

If the PVR is 2 or less, that's isolated postcapillary pH.

Group 2 pulmonary hypertension is caused by left heart disease.

Think heart failure with preserved ejection fraction, heart failure with reduced ejection fraction, valvular heart disease, and other left-sided cardiac conditions.

The key hemodynamic clue is an elevated PAWP.

If the wedge pressure is above 15, think post-capillary pH.