What is the purpose of the pop-off valve on a bag-valve-mask during manual ventilation?

• A. To replace the oxygen source
• B. To filter contaminants
• C. To release excess pressure during ventilation
• D. To regulate tidal volume

Answer: (C)

The pop-off valve is a safety feature that prevents dangerous airway pressures during manual ventilation. When you squeeze the bag, pressure can rise quickly, especially if the airway is resistant or the mask seal isn’t perfect. The valve vents excess pressure, keeping peak airway pressures within a safe range and protecting the lungs from barotrauma and reducing the chance of gastric inflation. It doesn’t replace the oxygen source, it doesn’t filter contaminants, and it doesn’t set the amount of air you deliver (tidal volume); that depends on how hard you squeeze the bag and the patient’s lung compliance. The valve’s job is simply to limit the pressure that can build up.