If you have an unwitnessed arrest in a child, what should you do?

In the case of an unwitnessed cardiac arrest in a child, the appropriate first step is to administer 2 minutes of high-quality CPR before activating the emergency response system and obtaining an AED. This approach is grounded in the recognition that children have a higher likelihood of experiencing a respiratory cause of arrest, which can lead to cardiac arrest. Initiating CPR immediately helps to maintain blood circulation and oxygenation to vital organs, especially the brain, increasing the chances of a successful resuscitation when advanced care arrives.

By performing CPR for a couple of minutes first, you are addressing the critical need for circulation before calling for help, thus maximizing chance of survival. Following this initial two minutes of CPR, it's essential to activate the emergency response system and retrieve an AED, as early defibrillation could be necessary depending on the child's condition.

Other options, such as checking for a pulse or beginning rescue breathing, may lead to delays in effective chest compressions or fail to provide sufficient help during the crucial early moments of cardiac arrest. Therefore, the emphasis on immediate CPR is the most lifesaving action in this scenario.