Introduction
Obstructive sleep apnea hypopnea syndrome (OSAHS) in children is characterized by prolonged partial upper airway obstruction and/or intermittent complete obstruction that disrupts normal ventilation during sleep and normal sleep patterns, causing cognitive impairment and cardiovascular diseases in children[1],. The incidence rate of OSAHS in children ranges from 1.2% to 5.7%[2]. PSG is the gold standard for the diagnosis of OSAHS[3] .However, PSG is difficult to perform universally in primary hospitals. Alternatively, parent-reported history and physical examination are widely used for clinical decision-making[4].The American Academy of Paediatrics recommends alternative diagnostic tests or referral to a specialist for more extensive evaluation when PSG is not available and when an adequate treatment strategy has not been developed. Therefore, clinicians rely on physical examination (e.g, tonsil size), radiological findings et al to diagnose and determine paediatric OSA.
Adenoid hypertrophy is the main risk factor for OSAHS in children[5,6], accounting for approximately 70% of cases. Nasopharyngeal lateral radiographs are commonly used to assess adenoid hypertrophy. The A/N ratio is used to assess the size of the adenoids. Some studies[7,8]have shown that adenoidal hypertrophy is associated with LSaO2 and the severity of OSAHS in children. Additionally, some studies [9,10] have shown a correlation between adenoid size and logAHI, apnoea index, and duration of obstructive apnoea. However, a previous study[11] revealed that adenoid size cannot be used to predict the severity of AHI.
In summary, nasopharyngeal lateral radiography is a feasible tool for screening OSAHS; however, its correlation with PSG monitoring results still needs to be further investigated. Therefore, this study aims to investigate the diagnostic value of the A/N ratio for the primary screening of OSAHS in children.