G98 Attention deficits in paediatric sickle cell disease; links with nocturnal oxygen desaturation in adolescents, but not children

Aim Homozygous sickle cell anaemia (SCA; HbSS) is associated with neurological compromise and attention difficulties. Previous work has shown tentative links between executive dysfunction and daytime oxygen desaturation in SCA. Previous work has not however examined the effects of nocturnal oxygen saturation on attention, nor has it considered whether any relationship is confounded by the effects of socio-economic status (SES) or age. Methods Thirteen children (8–12 years, 6 Female) and twentytwo adolescents (13–18 years, 11 Female) with SCA enrolled on the Prevention of Morbidity in Sickle Cell Disease Phase 2 randomised controlled trial of auto-adjusting continuous positive airways pressure underwent cognitive assessment at baseline, which included the Conners’ Continuous Performance Test (CPT). Overnight oximetry was conducted at home within two weeks of assessment. Multiple deprivation indices (MDI) were derived from postcodes. Results In adolescents, after correcting for the effects of MDI, correlations were found between time spent with oxygen saturation Conclusion This study confirms, for the first time in SCA, links between hypoxia and attention deficits. The relationships hold when SES is taken into account. The absence of similar links and existence of a relationship in the opposite direction in children requires further scrutiny. These preliminary data indicate that the effects of hypoxia on these domains may only emerge during brain development in adolescence. CPT performance may serve as a useful cognitive endpointfor trials of reducing hypoxic exposure.