This is a research study using caffeine in children who have an obstructive sleep apnea (OSA). OSA means children who stop breathing during their sleep due to obstruction in their airway. The purpose of this study is to determine whether caffeine when given in the vein, will wake children up faster and decrease post-anesthesia airway obstruction, as well as the safety and if the drug agrees with the child compared to a placebo (an inactive or dummy agent).