What should be the primary action when a patient's airway is obstructed?

When a patient's airway is obstructed, the primary action should be to perform abdominal thrusts. This technique, often referred to as the Heimlich maneuver, is designed to expel an object that is blocking the airway, allowing the patient to breathe again. The abdominal thrusts create pressure that can forcefully push the object out of the airway, restoring airflow.

Checking for breathing, while important in assessing the situation, is secondary to the immediate need to clear an obstruction. Administering oxygen is not effective in cases of airway obstruction, as the oxygen cannot reach the lungs if the airway is blocked. Similarly, beginning chest compressions is indicated when a patient is in cardiac arrest, but it does not address the immediate need to clear an obstructed airway. Therefore, performing abdominal thrusts is the critical action that should be taken in this scenario.