The 15-month-old you are treating is in respiratory arrest. pulse still present at 108, skin is cyanotic. mom states the baby was fine a minute ago and when she came back, her daughter wasn't breathing. you open the airway and make an attempt to ventilate but no air goes in. you reposition the child with padding under her shoulders and reattempt ventilations, but still no air entry is achieved. what is your course of action now?