Leak Around Endotracheal tube In A 6 year Old child

A six-year-old child is intubated with a size 4.5 mm ID endotracheal tube. Following intubation, there is a large leak of air around the tube, audible at the
mouth.
What is the most clinically significant effect of endotracheal intubation with a tube that is too small?
 Select ONE answer only:
A. Environmental pollution of anaesthetic gases
B. High gas flow consumption
C. Imprecise capnography
D. Increased risk of pulmonary aspiration
E. Unreliable ventilation and oxygenation

Answer:
E. Unreliable ventilation and oxygenation.

Discussion: An uncuffed endotracheal tube that is too small results in an air leak around the tube. While large air leaks cause all of the effects listed, it is unreliable ventilation and oxygenation that is
immediately relevant to the patient. This is a particular problem when the airway resistance is high, e.g. in bronchiolitis, as high airway resistance tends to increase the size of the leak and makes adequate ventilation difficult.