A man in a diner suddenly begins gasping, then becomes silent and cyanotic. What should you do?

The situation described depicts a person who is experiencing a severe airway obstruction, indicated by gasping and becoming silent and cyanotic. In cases of suspected choking where someone cannot speak and shows signs of respiratory distress, performing abdominal thrusts (also known as the Heimlich maneuver) is the appropriate response. This technique can help to create enough pressure in the abdomen to expel the object blocking the airway, thus restoring normal breathing.

Administering oxygen could be beneficial in other situations, but it wouldn’t address the immediate airway obstruction. Beginning CPR is also not the first step here, as CPR is indicated only when the person is unresponsive and not breathing following unsuccessful attempts to clear the airway. Conducting a blind finger sweep is not advised in this scenario because it could push the obstruction further into the airway instead of removing it. Therefore, performing abdominal thrusts is the most effective and urgent way to attempt to resolve the blockage in this critical situation.