Final answer:
The first drug to administer to a child in cardiac arrest during CPR is Epinephrine. It assists by increasing blood flow and heart rate. Other drugs such as Atropine, Amiodarone, and Lidocaine are used for different cardiac scenarios.
Step-by-step explanation:
The most important drug to administer to a child in cardiac arrest while CPR is being performed is Epinephrine. This medication plays a critical role in managing cardiac arrest by increasing blood flow to the heart and brain, enhancing the chance of return of spontaneous circulation (ROSC). It can constrict blood vessels and increase heart rate, which in turn helps to maintain blood pressure and vital organ perfusion during a cardiac event. CPR (cardiopulmonary resuscitation) should be performed immediately, and if available, an automated external defibrillator (AED) should be used before administering any drugs.
While Atropine, Amiodarone, and Lidocaine also play roles in emergent cardiac care, they are typically considered in different scenarios or after initial treatment with epinephrine and defibrillation if needed. Atropine is used in specific bradycardia presentations, Amiodarone for recurring ventricular arrhythmias, and Lidocaine also for ventricular arrhythmias though it is less commonly used now.