While using a self-inflating manual resuscitator, the bag collapses easily when squeezed and the newborn's chest does not rise. Which of the following would cause this to occur?

While using a self-inflating manual resuscitator, the bag collapses easily when squeezed and the newborn's chest does not rise. Which of the following would cause this to occur?

• A. Insufficient flow to the bag
• B. The patient's compliance has decreased
• C. An absent inlet valve
• D. The patient's airway resistance has increased

Answer: (C)

The key idea is how a self-inflating resuscitation bag re-expands between squeezes. It fills again from ambient air through an inlet valve. If that inlet valve is absent or defective, air cannot enter the bag when you release it, so the bag remains collapsed and cannot deliver air to the lungs. That’s why the bag collapses easily when squeezed and the newborn’s chest doesn’t rise—the patient isn’t being ventilated at all. Other scenarios don’t fit this pattern as neatly. If there were insufficient flow to the bag, or if the patient’s airway resistance or lung compliance changed, you’d expect changes in how effectively air is delivered or how hard you must squeeze, but the bag would still re-expand between compressions because ambient air can still enter through the inlet valve. The missing inlet valve specifically prevents the bag from re-expanding, stopping ventilation at its source.

The key idea is how a self-inflating resuscitation bag re-expands between squeezes. It fills again from ambient air through an inlet valve. If that inlet valve is absent or defective, air cannot enter the bag when you release it, so the bag remains collapsed and cannot deliver air to the lungs. That’s why the bag collapses easily when squeezed and the newborn’s chest doesn’t rise—the patient isn’t being ventilated at all.

Other scenarios don’t fit this pattern as neatly. If there were insufficient flow to the bag, or if the patient’s airway resistance or lung compliance changed, you’d expect changes in how effectively air is delivered or how hard you must squeeze, but the bag would still re-expand between compressions because ambient air can still enter through the inlet valve. The missing inlet valve specifically prevents the bag from re-expanding, stopping ventilation at its source.