What technique is not recommended for opening an infant's airway?

The technique that is not recommended for opening an infant's airway is overextension. In infants, the anatomy of the airway is quite different from that of older children and adults, and the airway is more easily obstructed. Overextending the head can lead to airway blockage rather than opening it, as it can affect the positioning of the tongue and soft tissues, thereby compromising the airway.

In contrast, techniques such as the sniffing position, jaw thrust, and chin lift are safe and effective in facilitating airway management in infants. The sniffing position helps align the airway passages by slightly elevating the head, while both the jaw thrust and chin lift are used to move the tongue forward and clear any obstruction without risking further airway compromise.