Final answer:
If a child remains unresponsive and pulseless after initial CPR efforts, the rescuer should immediately use an Automated External Defibrillator (AED). The AED can diagnose the heart's condition and administer a shock, potentially restarting the heart. During this process, continued high-quality chest compressions are crucial.
Step-by-step explanation:
In a situation where you have a 6 year old child who is unresponsive and without a pulse even after two minutes of CPR, the next step would be to use an Automated External Defibrillator (AED). Given that CPR has already been administered and the child still does not have a pulse, applying an AED is critical. AEDs are designed to be used by laypersons and will provide verbal instructions upon use. They can diagnose the heart condition and apply a shock with the appropriate energy to potentially restart the heart. Furthermore, AEDs can be essential in cases of cardiac or ventricular fibrillation by applying a controlled shock to terminate arrhythmia and allow the body's natural pacemaker to resume normal rhythm. As specified in emergency protocols, high-quality chest compressions should be continued until the AED is set up and ready for use, or until advanced support arrives.