There is no strict time requirement for sputum aspiration, and it is generally recommended to perform it 30 minutes after meals.
Sputum aspiration is generally using negative pressure suction device through the mouth, nose or tracheotomy to suck out the secretion and keep the respiratory tract open, usually used for coma, tracheotomy, anesthesia before waking up and other patients who can not effectively expel sputum, usually can be carried out when there is a lot of secretion, and it is recommended that sputum aspiration be carried out after 30 minutes after meals so as to avoid nausea, vomiting and other uncomfortable symptoms.
Oxygen is recommended half a minute before sputum suction to maintain normal oxygen saturation to avoid hypoxia during sputum suction, and the time of each sputum suction should be less than 15 seconds to avoid hypoxia caused by too much time of sputum suction.
Sputum aspiration needs to be performed with the help of a healthcare professional.