Diagnostic and severity classification criteria of PSG in children with sleep disordered breathing

OBJECTIVE ①To investigate the appropriate PSG (polysomnography) criteria in children with OSAHS (obstructive sleep apnea/hypopnea syndrome). ②To explore the pathogenesis of cognitive defects in children with sleep disordered breathing. METHODS Children with snoring were recruited. Questionnaires were filled out and PSG was performed for all the children. Apnea/hypopnea index (AHI), obstructive apnea index (OAI), oxygen desaturation index (ODI), arousal index and minimum oxygen saturation were analyzed. RESULTS A total of 124 children with snoring were recruited. There were 105 children who has either AHI 5 or OAI 1, occupying 87% of the total subjects. Patients were divided into two groups depending on whether they had cognitive defects or not. There were no differences between the two groups regarding the age, gender and BMI (body mass index). AHI, OAI, ODI, the minimum oxygen saturation and arousal index were significantly different between the two group with P value of 0.001, 0.019, 0.018, 0.001 and 0.033 respectively. Logistic regression test showed that, after controlled for age, gender, AHI, ODI and other PSG parameters, the minimum oxygen saturation was the independent factor that correlated with cognitive disability (P=0.005). CONCLUSION Paediatric patients with either AHI5 or OAI1 should be considered as having OSAHS. Nocturnal hypoxemia is the major cause of cognitive defects in OSAHS children. While classifying the severity of childhood OSAHS, the minimum oxygen saturation should be paid more attention to as well as AHI.