Which statement about PEEP is correct?

Which statement about PEEP is correct?

• A. PEEP reduces the need for oxygen therapy
• B. PEEP helps keep alveoli open at end expiration to improve oxygenation
• C. PEEP directly removes carbon dioxide
• D. PEEP eliminates the risk of barotrauma

Answer: (B)

PEEP keeps alveoli open at the end of expiration. By applying a small positive pressure in the airways at the end of each breath, it prevents alveolar collapse, recruits atelectatic units, and increases the functional residual capacity. With more alveoli participating in gas exchange, oxygen transfer from air to blood improves and intrapulmonary shunt decreases, leading to better arterial oxygenation. Carbon dioxide removal isn’t a direct effect of PEEP; CO2 elimination depends mainly on the minute ventilation (how much air is moved in and out per minute). PEEP can sometimes help ventilation efficiency indirectly, but it does not “remove” CO2 by itself. It also does not eliminate the risk of barotrauma; if PEEP is set too high, it can raise airway and lung pressures and potentially cause injury or affect hemodynamics.

PEEP keeps alveoli open at the end of expiration. By applying a small positive pressure in the airways at the end of each breath, it prevents alveolar collapse, recruits atelectatic units, and increases the functional residual capacity. With more alveoli participating in gas exchange, oxygen transfer from air to blood improves and intrapulmonary shunt decreases, leading to better arterial oxygenation. Carbon dioxide removal isn’t a direct effect of PEEP; CO2 elimination depends mainly on the minute ventilation (how much air is moved in and out per minute). PEEP can sometimes help ventilation efficiency indirectly, but it does not “remove” CO2 by itself. It also does not eliminate the risk of barotrauma; if PEEP is set too high, it can raise airway and lung pressures and potentially cause injury or affect hemodynamics.