Final answer:
The recommended initial defibrillation dose for a child in cardiac arrest with a rhythm of V Fib is 2-4 joules per kilogram. For a child weighing 20 kg, the initial dose should be 40 joules, and if necessary, increase to 80 joules for subsequent shocks as per American Heart Association guidelines.
Step-by-step explanation:
As a team leader managing a pediatric cardiac arrest with the patient presenting in ventricular fibrillation (V Fib), the recommended initial defibrillation dose is 2-4 joules per kilogram (J/kg) of body weight. For a child weighing 20 kg, the appropriate defibrillation dose would range from 40 to 80 joules.
The American Heart Association provides guidelines for defibrillation in children, which state that the first dose should be 2 J/kg and, if not successful, increase to 4 J/kg for subsequent shocks. Considering the child's weight of 20 kg, one would initially use 40 joules (20 kg x 2 J/kg), and if a second shock is required, 80 joules may be considered (20 kg x 4 J/kg). As circumstances vary, clinical judgment and protocol adherence are crucial in determining the optimal energy level for defibrillation in a pediatric cardiac arrest scenario.