If you are the only BLS provider responding to an unresponsive infant who is not breathing, what should you do when you do not feel a brachial pulse?

When responding to an unresponsive infant who is not breathing and there is no brachial pulse felt, the recommended action is to immediately start high-quality CPR, beginning with chest compressions. This approach aligns with the vital importance of restoring circulation and oxygenation to the infant's vital organs as quickly as possible.

In cases of cardiac arrest, timely intervention is critical. High-quality CPR helps maintain blood flow to the heart and brain, which can prevent irreversible damage. The guidelines emphasize starting with chest compressions, followed by administering rescue breaths if trained to do so.

This option is rooted in the urgency of the situation, where the lack of a detectable pulse indicates that the heart is not effectively pumping blood, thus necessitating immediate resuscitative efforts. By starting CPR right away, you maximize the chances of survival and recovery for the infant.