B is for BREATHING. If the child remains unresponsive and still not breathing on his own, pinch his nose with your fingertips or cover his mouth and nose with your mouth creating a tight seal, and give two breaths (Figure 1).
Keep in mind that children's lungs have much smaller capacity than those of adults. When ventilating a child, be sure to use shallower breaths and keep an eye on the victim's chest to prevent stomach distention.
If this happens and the child vomits, turn his head sideways and sweep all obstructions out of the mouth before proceeding. After you've administered the child two breaths and he remains unresponsive (no breathing, coughing or moving), check his circulation