A 4-year-old child is unresponsive with a pulse rate of 65 bpm but not breathing normally. What is the appropriate action to take?

In this scenario, where a 4-year-old child is unresponsive, has a pulse rate of 65 bpm, and is not breathing normally, the appropriate action is to deliver one ventilation every 3 to 5 seconds. This decision is based on the recognition that although the child retains a pulse, which indicates some level of circulation, the absence of normal breathing signifies a critical need for assisted ventilation.

When a child is unresponsive with inadequate respiratory efforts but has a pulse, the priority shifts to supporting their breathing. Delivering one ventilation every 3 to 5 seconds allows for adequate ventilation without causing respiratory over-distension or interruption to the circulation. This interval helps ensure that the child receives sufficient oxygen, which is crucial for brain function and overall survival.

Monitoring the pulse at regular intervals, as suggested in some other options, is important but takes a lower priority compared to ensuring the airways are adequately ventilated. The focus primarily should be on providing those ventilations while continuously assessing the situation, given the child's critical state.