In Pulmonary edema pulmonary capillary wedge pressure is ?
**Core Concept**
Pulmonary capillary wedge pressure (PCWP) is a measure of the pressure in the left atrium, which reflects the left ventricular end-diastolic pressure (LVEDP) in the context of pulmonary edema. It is an indirect indicator of left ventricular function and is used to assess the severity of heart failure.
**Why the Correct Answer is Right**
PCWP is measured during a pulmonary arterial catheterization, where the catheter is wedged in a small pulmonary capillary. The pressure recorded at this point is equal to the left atrial pressure, which in turn is equal to the LVEDP. In pulmonary edema, the left ventricle is unable to adequately pump blood, leading to increased pressure in the left atrium and subsequently in the pulmonary capillaries. This increased pressure is reflected by the elevated PCWP.
**Why Each Wrong Option is Incorrect**
**Option A:** PCWP is not a measure of the pressure in the right atrium, as it is not directly related to the right ventricular function.
**Option B:** PCWP is not a measure of the pressure in the pulmonary arteries, as it is measured at a point where the catheter is wedged in a small pulmonary capillary.
**Option C:** PCWP is not a measure of the pressure in the bronchi, as it is related to the left atrial pressure, not the airways.
**Clinical Pearl / High-Yield Fact**
In patients with pulmonary edema, an elevated PCWP (>18 mmHg) is indicative of left ventricular dysfunction, while a normal PCWP (<18 mmHg) suggests that the pulmonary edema is due to other causes, such as high altitude or non-cardiogenic pulmonary edema.
**Correct Answer:** D. 18 mmHg