If a 3-year-old girl is unresponsive after ingesting narcotic painkillers, what should be your action?

In a situation where a 3-year-old girl is unresponsive after ingesting narcotic painkillers, the appropriate immediate action is to ensure her airway is open and provide adequate ventilation, which is why the correct response involves ventilating with a bag-mask device.

Narcotic overdose can lead to respiratory depression or apnea, resulting in inadequate oxygenation. Utilizing a bag-mask device allows you to provide positive pressure ventilation, which can help ensure that the child receives enough oxygen until further interventions can be executed.

While administering naloxone is crucial in narcotic overdose cases, it should typically follow after ensuring the child's airway is being adequately managed, especially if they are in a state of respiratory failure. Ventilating the child maintains oxygen delivery to vital organs while naloxone might take some time to exert its effect.

Chest compressions would be appropriate in a situation where there is no pulse or if the patient is in cardiac arrest, which may not be the immediate concern if the primary issue is respiratory depression. High-flow oxygen via a non-rebreathing mask could be supportive but does not address the immediate need for ventilation if the child is not breathing effectively.