What is the primary purpose of PEEP in neonatal ventilation?

• A. Increase carbon dioxide elimination
• B. Prevent alveolar collapse and improve oxygenation
• C. Decrease oxygen delivery
• D. Increase lung compliance

Answer: (B)

PEEP stands for positive end-expiratory pressure, and its main job in neonatal ventilation is to keep the tiny air sacs (alveoli) from collapsing at the end of each breath. In neonates, especially preterm infants with surfactant deficiency, many alveoli tend to close between breaths. By maintaining a small amount of pressure in the airways at end expiration, PEEP increases functional residual capacity, recruits collapsed alveoli, and reduces ventilation-perfusion mismatch (intrapulmonary shunt). The result is better oxygenation because more of the lung is available for gas exchange on each breath.

While PEEP can help improve lung compliance by preventing repetitive opening and closing, that’s a downstream effect rather than the primary purpose. It doesn’t directly enhance carbon dioxide elimination—that depends more on how aggressively you ventilate (rate, tidal volume) to remove CO2. It also isn’t intended to decrease oxygen delivery; the goal is to improve it through better alveolar recruitment. Be mindful, though, that excessive PEEP can impede venous return and affect hemodynamics, so it’s balanced carefully.