The narrowest part of larynx in infants is at the cricoid level. In administering anaesthesia this may lead to all except –: (A) Choosing a smaller size endotracheal tube, (B) Trauma to the subglottic region, (C) Post operative stridor, (D) Laryngeal oedema
Answer is A. Subglottic region (cricoid region) is the narrowest part of larynx in infants. Mucosal trauma to force a tube can cause post-operative edema, stridor, croup and airway obstruction.
The size of tube is very important, both oversize and undersize tube are dangerous :-


Oversize tube will increase the chance of trauma and post intubation edema, croup & stridor.
Undersize tube will increase the chance of aspiration (because uncuffed tubes are used in children and the best way to prevent aspiration is to use appropriate size tube).