What is the appropriate action if a pediatric patient's heart rate is less than 60 and does not respond to oxygen?

When a pediatric patient's heart rate falls below 60 beats per minute and there is no response to oxygen therapy, the appropriate action is to start CPR. This is critical because a heart rate under 60 in a child represents bradycardia, which can lead to inadequate cardiac output and a potential cardiac arrest. In this situation, immediate chest compressions can help maintain blood circulation and oxygen delivery to vital organs until more definitive treatment can be administered.

Starting CPR is a foundational aspect of advanced life support protocols, particularly if the patient shows no signs of responsiveness or their condition worsens even with initial oxygen administration. In contrast, while options like reassessing the airway or administering a fluid bolus might be important in different contexts, they do not directly address the immediate threat posed by the significantly low heart rate and potential lack of perfusion. High-flow oxygen therapy, similarly, will not resolve the critical situation if the child's heart rate continues to remain dangerously low. Therefore, initiating CPR is the most urgent and appropriate action in this scenario.