Common causes of OSAS in children include altered compliance due to increased upper airway resistance and factors affecting neuromodulation, with adenoid hypertrophy and/or tonsillar hypertrophy being its most common etiology. Domestic studies have found that among the obstructive causes of snoring and sleep apnea in children. 1. What are the common causes of obstructive sleep apnea hypoventilation syndrome in children? Any disease causing partial or complete obstruction of the upper airway can lead to obstructive sleep apnea hypoventilation syndrome, including the following causes: (1) Nasal: chronic rhinitis, sinusitis, nasal polyps, nasal masses, nasal septal deviation and posterior nostril atresia; (2) Nasopharynx and pharynx: the most common causes are adenoid hypertrophy, tonsillar hypertrophy, tongue hypertrophy, fat accumulation due to obesity, pharynx and nasopharynx (3) larynx and trachea: congenital laryngeal cartilage softening, laryngeal webbing, laryngeal cysts, laryngeal tracheal neoplasm or tracheal stenosis, etc.; (4) craniofacial deformities. 2.How to determine if a pediatric patient has obstructive sleep apnea hypoventilation syndrome? The gold standard for determining whether a pediatric patient has obstructive sleep apnea hypoventilation syndrome and its severity is to perform an all-night multi-channel sleep apnea monitoring test. For children with sleep problems, regardless of whether they have adenoid tonsil hypertrophy or nasal lesions, they should undergo an overnight multi-channel sleep apnea monitoring test to determine whether they have obstructive sleep apnea hypoventilation syndrome and to determine the severity of their lesions and hypoxia based on the test results, and then decide on the next step of treatment. 3.What is overnight multi-channel sleep breathing monitoring? Is sleep apnea monitoring harmful to the pediatric body? Overnight multi-channel sleep apnea monitoring is to monitor the respiratory status, electroencephalographic activity, electrocardiographic activity, eye movement, chin movement and blood oxygenation of children during sleep at night, and then determine whether the child has sleep apnea and hypoxia, and finally determine whether there is sleep apnea hypoventilation syndrome. The test is performed by means of an oronasal airflow sensor placed around the child’s mouth and nose, a chest and abdominal belt, and electrodes placed on the child’s head, around the eyes, and under the chin to continuously and simultaneously record more than 10 indicators such as EEG and respiration during sleep. The placement and connection of electrodes in the overnight multi-channel sleep apnea monitoring is similar to the operation method of electrocardiogram, and it is a test without any damage to children. 4.Where is the sleep apnea monitoring test performed? Sleep apnea monitoring is to monitor the structure and breathing of pediatric sleep at night, and the total time of monitoring should be at least 6 hours. This test needs to be done in a specific sleep apnea monitoring room. Children can be accompanied by a parent during sleep apnea monitoring and sleep overnight in the sleep apnea monitoring room to complete the entire procedure. Sleep apnea monitoring in children requires a specific monitoring environment, professional technicians, sophisticated instruments, a high level of expertise and expensive equipment. The Sleep Apnea Monitoring Room in the Department of Respiratory Medicine of the Children’s Hospital of the Capital Institute of Pediatrics is one of the only two sleep apnea monitoring rooms for children in Beijing, located in the respiratory ward on the second floor of the ward building. 5.How to ensure the successful completion of sleep apnea monitoring for children? The sleep apnea monitoring room is an unfamiliar environment for children. In order to ensure the sleep quality of children, eliminate their fears and ensure the smooth performance of sleep apnea monitoring, parents should pay attention to the following matters before bringing their children for sleep apnea monitoring: (1) Actively communicate with children and explain to them in detail that the examination is painless, similar to playing a game, by putting some electrodes on their bodies to obtain some information. (1) Actively communicate with the child and explain that the test is painless, similar to playing a game, by putting some electrode pads on the child’s body to get some information and finally determine how the child is doing. (2) To ensure that the child can sleep smoothly and that the test results are true, do not drink caffeinated beverages, such as tea, cola, chocolate and coffee, from noon on the day of the test; do not let the child take a nap on the day of the test; (3) To facilitate the test, bring a loose (3) To facilitate the examination, bring a loose pajamas and pajama pants, the pajamas must be of a style that can be untied in front; (4) To facilitate the paste of electrodes, please wash your hair and take a bath at home with soap before the examination, and do not use shampoo to wash your hair.