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Pulmonary edema
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Pulmonary edema is fluid that collects inside the lung where it should not be. It is extravascular fluid, meaning it sits outside the blood vessels, and it collects in the parenchyma, the tissue that makes up the lung. That is where the alveoli are, the tiny sacs where air hands off oxygen to the blood, and with fluid in the way, gas exchange drops. The lung, built to fill with air, gets soaked like a sponge.
The fluid gets there by two routes. In cardiogenic edema, hydrostatic pressure, the pressure of the fluid inside the lung's capillaries, the smallest blood vessels, rises quickly. In noncardiogenic edema, the problem is an injury to the lung itself: the vessels become more permeable, like a sieve, and let protein-rich fluid through into the alveoli and into the interstitium, the space around them.
In both cases, the person has shortness of breath that keeps getting worse, breathes rapidly and has hypoxia, which is low oxygen, and listening to the chest reveals crackles, a crackling sound.
In brief
Pulmonary edema is an abnormal buildup of extravascular fluid in the lung parenchyma that reduces gas exchange in the alveoli.
The lung, built to hold air, gets soaked like a sponge.
There are two main types. In cardiogenic edema, hydrostatic pressure in the pulmonary capillaries rises rapidly; in noncardiogenic edema, lung injury increases vascular permeability and lets protein-rich fluid into the alveoli and interstitium.
Both cause progressively worsening shortness of breath, rapid breathing, crackles on auscultation and hypoxia.
Sources (1)
- National Center for Biotechnology Information, StatPearls PublishingPulmonary Edema, StatPearlsPublished
This page explains the topic in general terms; it does not tell anyone what treatment to follow.
Updated