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My understanding is that what a ventilator does is basically: - supply pressurized air to patient - turn off the pressure, open exhalation valve and let patien

• cameldrv 7y ago
  My layman's understanding is that ventilation is a fairly complex art/science, and that modern ventilators have multiple modes that are effectively different control laws. I think that the pressure required to fill a patient's lungs is quite different in a COVID patient than a normal patient, because the disease has caused huge flow restriction in the lungs. I think that generally you want to control flow rate, because you need to get a particular respiration rate, and the lungs can hold a certain amount of air. You then use whatever pressure gets that respiration rate. If the pressure or flow rate is too high, I think that that can cause lung damage, so one option is to increase the oxygen concentration in the air you're delivering. My understanding is that the downside is that although this will lead to more oxygenation, it doesn't help any with removing CO2. If you reach this limit, the only option is then ECMO.
  • loeg 7y ago
    > My understanding is that the downside is that although this will lead to more oxygenation, it doesn't help any with removing CO2. If your input is O2 (or O2+N, no CO2) and you run part of the pressurization cycle with the exhalation valve open, won't you displace at least some CO2 (not in tissue, just in the lung cavity)?