G512(P) Children with achondroplasia – when to refer for a polysomnography?

Introduction Achondroplasia is the most frequent form of short-limb dwarfism. These children have hypotonia, micrognathia and mid-facial hypoplasia that predispose them to sleep-disordered breathing (SDB). Repeated assessments with polysomnography (PSG) are recommended to screen these children for SDB. However, as PSG is not widely available, clinicians have to rely on their clinical assessment to guide referral for further assessment. Aim To record the presenting symptoms and PSG findings in children with achondroplasia referred to our sleep service, and to ascertain whether any clinical symptoms were indicative of SDB. Method We performed a retrospective review on children with achondroplasia who had a PSG performed during the last eight years (2011–2018). Parents completed sleep questionnaires prior to the study on questions pertaining to children’s sleep habits, breathing in sleep, daytime symptoms and daytime breathing. Patients’ demographic data, symptomatology and PSG results were noted in structured proformas. Results Sixteen polysomnograms were performed in children with achondroplasia during the study period; 10 (63%) of which were positive for SDB. Their mean age was 4.41±3.5 years. Discriminatory sleep symptoms present in patients with and without SDB are shown in the table below (table 1). Conclusions This study suggests that some symptoms may guide clinicians in their assessment of SBD in children with achondroplasia. Night-time awakening, mouth breathing, excessive sweating during sleep, excessive daytime sleepiness, tiredness and difficulty to wake up in the morning suggest SDB in these children. These symptoms were more discriminatory than the commonly reported symptoms like snoring or restless sleep. This information can help clinicians with the history-taking to identify patients needing referral for a PSG.