P051 Predicting diagnosis of obstructive sleep hypopnea-apnea syndrome in children with asthma: an alternative to cardiorespiratory polygraphy

Introduction Both asthma and obstructive sleep hypopnea-apnea syndrome (OSAHS) can cause nocturnal hypoxemia and breathing difficulty. Prevalence of OSAHS in children with asthma is reported as 63%; incidence in our cohort of severe therapy resistant asthma is only 9%, postulated to be due to good adherence to anti-inflammatory medications. Due to limited availability of level 2 studies and the volume of referrals received for asthmatic children we planned to identify whether reported symptoms and/or oxygen desaturation index (ODI) alone could accurately diagnosis OSAHS in these patients. Methods Retrospective review of cardiorespiratory polygraphies with transcutaneous CO2 monitoring that were performed in tertiary paediatric respiratory centre in children with a primary diagnosis of recurrent wheeze or asthma between January 2018 and May 2019. Clinical data including anthropometry, sleep symptoms and all sleep study parameters were collected. Data analysis was undertaken using Prism 8.0 (GraphPad, USA). Results 40 patients (75% male) were reviewed. Mean age at time of study was eight years (SD ± 4.24). Mean BMI 21.24 kg/m-2 (SD ± 6.99). Treatment burden was variable; 39/40 patients were on inhaled corticosteroids with 4 patients on biologicals. At the time of the study, concerns about treatment adherence were present in at least 25% of patients. Out of eight parent-reported symptoms (table1), snoring was the commonest symptom and mean Cardiorespiratory Polygraphy Parameters (table 2) were within the reference range except for ODI. 2(5%) patients had oAHI >5. oAHI positively correlated with parent-reported symptom score (r= 0.33, p= 0.03) and ODI (r= 0.400, p=0.01). Neither mean TcPCO2 (p=0.624) nor modified Epworth score (p= 0.352) correlated significantly with oAHI. Discussion A focused symptom analysis with oximetry to calculate ODI is useful for predicting OSAHS in children with asthma. This could conveniently be performed at home instead of level 2 studies being a first-line investigation.