With PEEP adjustment, PetCO2 should what?

With PEEP adjustment, PetCO2 should what?

• A. Increase
• B. Remain the same
• C. Decrease
• D. Fluctuate unpredictably

Answer: (B)

PetCO2 tracks alveolar ventilation, which is determined mainly by how you ventilate (tidal volume and respiratory rate). PEEP’s main role is to keep alveoli open and improve oxygenation by reducing shunt, not to change the amount of CO2 eliminated per breath. So as long as you keep the same minute ventilation, adjusting PEEP should not significantly alter PetCO2; it should stay about the same. Only large PEEP changes that markedly affect cardiac output or dead space would cause a noticeable PetCO2 shift, but that’s not the typical effect of routine PEEP adjustment.

PetCO2 tracks alveolar ventilation, which is determined mainly by how you ventilate (tidal volume and respiratory rate). PEEP’s main role is to keep alveoli open and improve oxygenation by reducing shunt, not to change the amount of CO2 eliminated per breath. So as long as you keep the same minute ventilation, adjusting PEEP should not significantly alter PetCO2; it should stay about the same. Only large PEEP changes that markedly affect cardiac output or dead space would cause a noticeable PetCO2 shift, but that’s not the typical effect of routine PEEP adjustment.