Nasogastric Tube Feeding were used for feeding to provide nutritional support. Each feeding was administered by a nurse using the infant's mother's breast milk through the tube. The amount of each feeding varied from 20 to 100 ml depending on the age of the infant, with feedings given every 2 to 3 hours, approximately 10 times per day. The duration of each feeding procedure ranged from 10 to 20 minutes. The total daily intake ranged from 200 to 1000 ml. Each tube was kept indwelling for 5 to 7 days. When the tube needed to be replaced, it was removed after the last feeding of a day and a new tube was to be inserted through the other nostril on the following morning to continue the nutritional support.

Both groups were given comprehensive rehabilitation therapy. The main intervention measures included: 1) non-invasive ventilator treatment, generally at least once every night and typically not exceeding continuous daily usage.; 2) attention to feeding and sleeping positions, with a recommended sleeping position of lateral recumbent and the head of the bed raised by 20-30°; 3) swallowing function training, such as tongue muscle stretching training, assisted anterior jaw protrusion training, lemon ice stimulation to the soft palate, pharyngeal wall, etc., generally 5 days per week, twice per day, 5-20 minutes each time; 4) pulmonary ultrashort wave therapy, generally at least 2-3 times a week, and not more than once a day; 5) physical therapy, such as intensive training for gross motor functions including lifting the head, turning over, sitting, crawling, standing, etc., generally 3-5 days per week, 1-2 times per day, 5-20 min each time.

The relevant indicators include albumin (ALB, g/L)from the blood test within 24h after admission and the last day of treatment, generally, with empty-stomach infants and in the morning.

The Yale pharyngeal residue severity rating scale was recruited for assessment, of which the result would be divided into 5 levels (1, no residue; 2, the covered pharyngeal mucosa; 3, mild residue, less than 50%; 4, moderate residue, more than 50%; 5, severe residue, spillage from laryngeal vestibule observed).As the level increased, the severity of dysphagia also increased.

The depression of the patients was evaluated with the patient health questionnaire-9. The scores ranged 0-27. As the scores increased, the severity of depression also increased.

Swallowing Quality of Life questionnaire was used to evaluate the quality of life, which consists of 44 items and divided into 11 main domains, including: overall satisfaction, understanding, diet, hydration, communication, respiratory issues, postoperative recovery, social impact, mental health, saliva control, and appearance. The maximum rough score was 220 points, which was converted into a standard percentage system in our study. As the scores increased, the quality of life was better.