sarahs mum said:
What happens to fluid build up in the lungs when you’re on a respirator?
With the caveat that I am not a doctor or biologist or anything like that:
When we breathe in the air travels down various tubes and arrives at the alveoli, small “sacks” in the lungs. For our purposes, think of the alveoli as tiny little spheres with a surface that is permeable to oxygen. Once in the alveoli, the oxygen is forced by the pressure of the air (normally at the local atmospheric pressure) through the permeable surface of the alveoli and in to the blood stream. This is why, for example, it’s still perfectly easy to take a deep breath on the top of Mount Everest, but the air is considered “thin” because there is little atmospheric pressure to force the oxygen through the permeable surface.
Fluid in the lungs usually means that the alveoli are filling up with fluid. Imagine the spherical alveoli half full of water. Now only half the permeable surface is available for oxygen to be forced through and in to the blood stream, so the patient would only be getting half the oxygen they usually get.
When this happens doctors can supplement the amount of oxygen going in to the lungs. Half as much getting in to the blood stream? Then double the amount of oxygen and you are good to go. If simply increasing the amount of oxygen isn’t enough then they can increase the pressure which that oxygen is delivered to the lungs at, so forcing more oxygen in to the blood stream that way.