Efficacy of cycled environmental light and noise during initial hospitalisation for improved cognitive outcomes at 2 years in infants born extremely or very preterm: study protocol for the prospective, randomised, open, blinded endpoint controlled multicentre CIRCA DIEM trial.

Abstract

Very preterm infants (<32 weeks gestation) have an undeveloped primary endogenous circadian rhythm and are deprived abruptly of vital maternal circadian inputs after delivery. Postnatal care in neonatal intensive care units is characterised by constant levels of lighting and noise. Stress arising from disrupted cues for circadian rhythmicity likely disrupts development of coordinated circadian rhythms critical for neurogenesis, organ growth and development. We hypothesise that cycled environmental light and noise commenced soon after birth and continued until discharge home will improve cognitive outcomes compared with infants whose postnatal care comprises constant light (bright or dim) and constant noise. Australasian multicentre, two-arm, parallel-group, prospective, randomised, open, blinded-endpoint superiority trial in 868 infants born less than 32 weeks' gestation. Infants are randomised to cycled environmental light and noise or routine care in a non-cycled hospital environment from soon after birth until discharge home. The intervention comprises wearing eye-masks and ear plugs from 20:00 to 6:00, followed by removal of these devices and exposure to normal environmental noise and 300-600 lux light from 6:00 to 20:00. The primary outcome is composite cognitive score on Bayley-4 developmental assessment at 2 years corrected postnatal age. The trial is approved by the Child and Adolescent Health Service Human Research Ethics Committee under the National Mutual Acceptance Scheme in Australia. Infants are randomised to intervention or control group after informed parental consent is obtained. Results of the CIRCA DIEM Study will be disseminated widely via presentations at local, national and international conferences, publication in international peer-reviewed journals and inclusion on the study website. Information about trial findings will also be communicated directly to the parents/guardians of trial participants through the regular study newsletter. The trial investigators will seek opportunities to communicate study results to the lay public through media and social media avenues. ANZCTRN12618000371291.