Once a person develop dysphagia (difficulty swallowing), phlegm would build up in their lungs. We need to do phlegm suction to avoid the phlegm from hardening and becoming a choking hazard.
YouTube videos on Phlegm Suction:
Here is a guide I have written on phlegm suction from my experience:
You can take a listen to the phlegm suction sounds, it is a bit unnerving. Please ensure the pressure is not too high (not higher than 140). Any pressure that is too high will cause bleeding.
Without phlegm suction, they would experience choking on their own phlegm. In the video below, I address the danger of choking due to aspirated food as well as on own phlegm/mucus. We can manage the risks from choking on aspirated food by ensuring we do not overfeed them (follow feeding schedule as check by aspirating their stomach contents to ensure previous feed has been digested) and keep them in a upward incline position of minimum 30 minutes after food: