The narrowest pa of larynx in infants is at the cricoid level. In administering anesthesia this may lead to all except.

A i.e. Choosing a smaller size endotracheal tubeEndotracheal tube that passes through the glottis may still impinge upon the cricoid cailage; the cricoid cailage is the narrowest point of the airway in children younger than 5 years of ageQMucosal trama can cause post operative edema, stridor, croup & airway obstruction() in subglottic & glotic regionThe appropiate size of tube is estimated by an age based formula, which provides only a rough guide line however. Exceptions include premature neonates (2.5 to 3 mm tube) and full term neonates (3-3.5 mm tube)Correct tube size is confirmed by easy passage into the larynx and the development of gas leak at 15-20 cm H20 pressure. So the size of ETT depends on age, easy passage & gasleak at 15-20 cm H20 pressure.