Nasopharyngeal suction with a catheter
Use a catheter attached to a portable or wall suction source. After lubricating the catheter, gently advance it through the nostril and direct it toward the floor of the nasal cavity. Advance the catheter toward the lower pharynx, until the patient coughs or resistance is felt. At that point, apply suction and slowly remove the catheter.
Nasopharyngeal suction is considered an aerosol-generating procedure (AGP). Personal protective equipment when performing this procedure with suspected/confirmed COVID-19 patients should include contact (gown and gloves) and airborne (N-95 with goggles/face shield or PAPR) precautions.
The length of time a room should be shut down after an aerosol-generating procedure is dependent upon how many air exchanges occur per hour. If a room is not a negative pressure room, ideally the room should be shut down for 60 minutes before cleaning to allow tiny particles suspended in the air to settle.
See complete guide on how to hook up suction in your practice.
There are also several videos available on-line that manufactures of nasal suction devices have created.