Clinical and Cardiorespiratory Polygraphy Profile in Children with Obstructive Sleep Apnoea Syndrome: A Cross-sectional Study

Cardiorespiratory Polygraphy (CRP) is a less costly and simplified alternative to time consuming and laborious over night polysomnography for diagnosis of Obstructive Sleep Apnoea Syndrome (OSAS) in children. The Apnoea Hypopnea Index (AHI) is simple and useful index that can be estimated by using CRP. The magnitude of AHI which reflects severity of OSAS is unknown in the paediatric population. Aim: To describe the clinical characteristics and to estimate AHI in a population of children with obstructive sleep apnoea and hypopnea syndrome. Materials and Methods: This cross-sectional observational study was conducted on 1500 children, below 12 years of age, from January 2018 to November 2018. They were screened using Paediatric Sleep Questionnaire (PSQ) in the Outpatient Departments of General Paediatrics and Pulmonology respectively, at the Institute of Child Health and Hospital for Children, Chennai, Tamil Nadu, India. Those children identified to have probable OSAS were made to undergo cardiorespiratory assessment. Children with craniofacial syndromes and congenital heart disease were excluded from the study. Anthropometric parameters, vital signs, and Body Mass Index (BMI) were recorded. AHI and oxyhaemoglobin desaturation index were estimated in CRP. After descriptive analysis, non parametric Mann-Whitney test was used to find out any significant difference in median values of AHI in clinical subgroups. Regression analysis was done between AHI values and BMI. Results: Total 47 children were subjected to cardiorespiratory polygraphy. There was no statistically significant difference in gender distribution and prevalence of adenoid enlargement (p-value=0.1447 and 0.7705, respectively). It was found that maximum occurrence of OSAS was at the age of 6 years (25.5%). Based on AHI score 44.7% children fell in moderate to severe OSAS category. There was a poor correlation between BMI scores and AHI, though no significant difference was observed (r=-0.266, p-value=0.07087). The difference in median AHI between males and females was not statistically significant (p-value=0.5256), while that between children with/without adenoid enlargement was statistically significant (p-value ≤0.001). Conclusion: Children with adenoid hypertrophy have higher AHI than children without adenoid hypertrophy. There is lack of evidence for male predominance in the study. Obesity poorly correlated with AHI score.