“Anapneo” is the incantation for a spell that clears the target’s breathing airway if blocked.
"anapneo" Gr. "breathe"
This is the Wizarding equivalent of the Heimlich maneuver. Slughorn's calm response to Belby's emergency is in stark contrast to Slughorn's paralyzed lack of action when Ron was poisoned.
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"Anapneo" from Harry Potter Wiki