Final answer:
To clear an 8-month old infant's severe airway obstruction, back blows and chest thrusts should be performed, not abdominal thrusts, until the obstruction is cleared.
Step-by-step explanation:
To relieve a severe airway obstruction in a responsive and choking 8-month old infant, one should perform back blows and chest thrusts. Abdominal thrusts, also known as the Heimlich maneuver, are not recommended for infants due to their delicate size and the risk of injuring internal organs. To carry out the back blows and chest thrusts, the rescuer should hold the infant face down, resting on their forearm, and deliver firm back blows between the infant's shoulder blades with the heel of their hand. Then, turning the infant face up, administer chest thrusts using two fingers in the center of the chest. These actions should be repeated until the obstruction is cleared or emergency medical services arrive.