That is pulmonary embolism, a blood clot. Not pulmonary edema.
Pul edema's main cause is heart failure, when the heart doesn't pump blood properly, so the kidneys retain all the extra fluids instead of pissing them out under the mistake that the body isn't getting all its fluids because the heart is failing and not pumping blood around properly. That causes fluid build up in the body, in worst cases making it harder to breathe and your body gets overloaded.
Source: I am a doctor.
Heart failure is normally managed with tablets and if needed IV medication. his must be pretty bad or end stage
