What does PEEP (Positive End Expiratory Pressure) do?

What does PEEP (Positive End Expiratory Pressure) do?

• A. Reduces tidal volume
• B. Increases carbon dioxide removal
• C. Prevents lung collapse during expiration
• D. Optimizes oxygenation

Answer: (D)

PEEP keeps airway pressure positive at the end of expiration, which prevents alveoli from collapsing and helps recruit more units for gas exchange. This raises functional residual capacity and improves oxygen transfer into the blood, making oxygenation better. It doesn’t directly reduce tidal volume (that’s a ventilator setting) and isn’t primarily about increasing CO2 removal — in fact, too much PEEP can sometimes cause CO2 retention. While preventing collapse during expiration is part of how PEEP works, the main clinical outcome we aim for is improved oxygenation, which is why optimizing oxygenation best describes what PEEP does.

PEEP keeps airway pressure positive at the end of expiration, which prevents alveoli from collapsing and helps recruit more units for gas exchange. This raises functional residual capacity and improves oxygen transfer into the blood, making oxygenation better. It doesn’t directly reduce tidal volume (that’s a ventilator setting) and isn’t primarily about increasing CO2 removal — in fact, too much PEEP can sometimes cause CO2 retention. While preventing collapse during expiration is part of how PEEP works, the main clinical outcome we aim for is improved oxygenation, which is why optimizing oxygenation best describes what PEEP does.