Obstruction of the airway during cardiac arrest is usually due to the relaxation of muscles in the throat causing the tongue to fall back and occlude the airway. The methods to open the airway include head tilt–chin lift, jaw thrust, mouth-to-mouth ventilation, mouth-to-nose ventilation, mouth-to-barrier device ventilation, and bag-mask ventilation.
The head tilt–chin lift is the best method for opening the airway.