Final answer:
After initial treatment fails for V Fib cardiac arrest in a child, the recommended drug to administer is Amiodarone at a dose of 5 mg/kg IO, according to ACLS guidelines.
Step-by-step explanation:
In the scenario provided, a child is experiencing a Ventricular Fibrillation (V Fib) cardiac arrest and has been given initial treatments including defibrillation and Epinephrine. After a subsequent rhythm check shows persistent V Fib, the team has administered another defibrillation shock. The next drug and dose to be administered should be Amiodarone 5 mg/kg IO. It's important to continue following Advanced Cardiovascular Life Support (ACLS) guidelines, which recommend Amiodarone for pediatric patients with refractory VF/pulseless VT after initial CPR and defibrillation attempts.