From March 2007 to December 2008, our department treated children with obstructive sleep apnea hypoventilation syndrome (OSAHS) by tonsillectomy and nasal endoscopic adenoid scraping, and we applied PSG sleep measurement before and after the operation to determine the diagnosis and evaluate the effect of the operation. 1. Data and methods 1.1. Data Children with obstructive sleep apnea hypoventilation syndrome admitted to our department from March 2007 to December 2008 were selected, including 55 males and 23 females; ages 2 to 13 years old, average 4.8 years old; disease duration 4 months to 6 years and 1 month. Body weight was in the normal range. The main reasons for consultation were sleep snoring, breath-holding, open-mouth breathing, frequent awakening during sleep, often accompanied by restless night sleep, night terrors and crying, sleep fear, sweating during sleep, urine loss, recurrent low-grade fever, nasal congestion, and excessive runny nose, which were often treated repeatedly for upper respiratory tract infections in the past. There were 49 cases of palatine tonsils with grade II hypertrophy or more; 68 cases of adenoid hypertrophy. Among them, 8 cases had structural obstruction of the nasal cavity due to nasal septal deviation and inferior turbinate hypertrophy. The adenoids were graded by nasal endoscopy [1]: grade I adenoid hypertrophy was located at the base of the junction of the posterior nasopharyngeal wall and obstructed the upper 1/3 of the posterior nostril, grade II adenoid hypertrophy obstructed the posterior nostril by 1/2, and grade III adenoid hypertrophy obstructed the posterior nostril by 2/3 or more. There were 13 cases of adenoid hypertrophy of degree I, 27 cases of degree II and 28 cases of degree III in this group. CT scan of the nasopharynx: all cases were scanned in axial and dislocated nasopharynx under awake condition [2]; A/N ratio less than 0.60 was considered normal (10 cases), 0.61-0.70 was considered moderate hypertrophy (27 cases), and ≥0.71 was considered pathological hypertrophy (41 cases). There were 21 cases of combined sinusitis. This accounted for 26.9% of the total cases. Polysomnography (PSG) test The diagnostic criteria for OSAHS in children were based on the 2007 “Draft diagnosis and treatment of obstructive sleep apnea hypoventilation syndrome in children” [3, 4], and polysomnography (PSG) was applied to all children with OSAHS to monitor the minimum oxygen saturation (LSaO2) for more than 7 hours and the accumulated time of oxygen desaturation <90% of the total monitoring time percentage (TS90%), and respiratory disturbance index (AHI) were determined in 18 cases of mild, 42 cases of moderate, and 18 cases of severe in this group. PSG monitoring was performed again for the same time 6 to 12 months after surgery. Sedation was disabled before the examination. 1.2. Methods Routine blood, urine, biochemistry, coagulation and electrocardiogram and chest X-ray were performed for children with more severe symptoms and children with previous cardiovascular and respiratory diseases. Preoperative continuous positive pressure ventilation (CPAP) was performed in 18 cases with preoperative AHI >20 times/h for about 3-5 days to improve the organism condition. All children were given general anesthesia by transoral intubation. The nasal endoscopic observation of the morphology of the nasal cavity and the degree of obstruction of the adenoid hypertrophy were recorded. The enlarged part of the inferior turbinate was appropriately excised or fractured and displaced in 4 cases, and the mucosa of the nasal septal crest was removed in 1 case. The adenoids were removed from the nasopharynx, and the palatine tonsils were removed by the conventional stripping method and completely stopped bleeding. Postoperative treatment and care: all children were given low-flow continuous oxygen for 1-2h, continuous cardiac monitoring for 2-3h, and systemic or local anti-infection, hormone, nasal mucosal constrictor and nasal clearance treatment (such as saline ephedrine nasal drops and chloramphenicol eye drops) for one week after surgery, and immune drugs were prohibited. PSG monitoring was performed for 7 h from 6 months to 12 months after surgery. 1.3 Statistical treatment The statistical package spss11.5 was used for statistical treatment. t-test for pairwise comparison was applied to compare the preoperative and postoperative PSG parameters. p < 0.05 was significant. 2. Results The children's postoperative open-mouth breathing disappeared and snoring symptoms disappeared significantly. Considering that it takes some time for the children to recover from local mucosal swelling after surgery, all 78 children underwent 7-hour nighttime sleep monitoring from 6 months to 12 months after surgery, and the efficacy assessment criteria were based on the 2007 Urumqi Draft of the Treatment of Obstructive Sleep Apnea Hypoventilation Syndrome in Children [3]. Compared with the pre-treatment period, 76 cases had significantly higher SaO2 (P < 0.01), significantly shorter total hypoventilation time (P < 0.01) and significantly lower AHI (P < 0.01) after treatment. The results also showed that the TS90% value increased gradually with the increase of OSAHS severity, and TS90% can reflect the severity of hypoxemia during sleep more objectively. The efficiency of this group reached 98% after the operation. 3. Discussion Structural obstruction of the upper airway is the main cause of sleep disordered breathing disease, and airway obstruction is mainly related to adenoids and tonsillar hypertrophy. The causes of nasal obstruction in children with OSAHS are mostly secondary to adenoid hypertrophy and other causes, such as nasal septal deviation, turbinate hypertrophy, and nasal masses, etc. If the treatment of nasal diseases is neglected during surgery, the surgical effect is thus greatly reduced. The children we choose to remove the mucosa of the inferior turbinate are often secondary to patients with perennial sinusitis and poorly contracted nasal mucosa stimulated by long-term inflammation. However, in clinical practice we find that pediatric OSAHS mostly resides around the age of 4-5 years and mostly presents with adenoid hypertrophy or palatine tonsillar hypertrophy. This may be the result of chronic inflammation of the nasopharynx or adjacent organs with long-term irritation. Preoperative CT scans of the nasopharynx in axial and dislocation positions and lateral nasopharyngeal radiographs can provide a good understanding of the nasal cavity and nasopharynx. Intraoperative nasal endoscopic observation can better reflect the degree of adenoid hypertrophy and can also help in the application of nasal aspirator excision. Preoperative preparation is especially important for younger children with greater risk of general anesthesia. Children with severe OSAHS have poor systemic function due to hypoxia, and it is best to treat them with continuous positive airway pressure (CPAP) prior to surgery until hypoxia improves to improve surgical safety. If there is a respiratory tract infection, it should be controlled before surgery. Surgical removal of adenoids and palatine tonsils is the main treatment for OSAHS in children with a surgical efficiency of 90% [5]. In our present report, the surgical efficiency of pediatric OSAHS was 98%, which was related to the selection of surgical indications (body mass index BMI <29.9 Kg/m2 ) and adequate preparation before surgery. At the same time, we also paid attention to the simultaneous treatment of nasal diseases. In the past, we neglected the treatment of nasal cavity diseases, which had poor postoperative results and required the treatment of secondary surgery. In our group of patients, the symptoms before admission basically disappeared after surgery. The treatment effect of pediatric OSAHS is significantly higher than our previous treatment effect of OSAHS in adults. PSG is the "gold standard" for the diagnosis of OSAHS, and monitoring the sleep architecture provides strong evidence for clinical staging and determination of the extent of the lesion. AHI and LSaO2 are the main criteria for the diagnosis of OSAHS and the extent of the disease, and Chesson [6] and others proposed the use of oxygen saturation <90% of the total monitoring time as an indicator to assess the severity of hypoxia in patients with OSAHS. The TS90% can reflect the severity of hypoxemia during sleep. In 78 pediatric patients with OSAHS, we performed surgical treatment according to the PSG test results and the degree of obstruction. The results showed that PSG monitoring not only provided a strong basis for the diagnosis of SAHS, but also provided information for the selection of treatment options for OSAHS patients. Although PSG testing is expensive and time-consuming for younger children, it can indicate changes in preoperative and postoperative clinical data, and can fully demonstrate the effect of surgical treatment, which is of great significance for clinical diagnosis and treatment.