Effects of a 12-hour light-dark cycle compared to continuous 24-hour lighting on clinical outcomes and length of hospital stay in preterm infants under 36 weeks of gestation in the Neonatal Intensive Care Unit of the Hospital General Regional 72, Instituto Mexicano del Seguro Social
Circadian rhythm disruption in preterm infants in the NICU
A controlled clinical trial was conducted in the Neonatal Intensive Care Unit (NICU) of Hospital General Regional 72 of the Instituto Mexicano del Seguro Social (IMSS), located in Tlalnepantla, State of Mexico. The study population consisted of a final analyzed sample of 40 preterm infants with a gestational age between 26 and 36 weeks at birth. The population was divided into two groups: The experimental group (n = 19) was exposed to a controlled 12-hour light-dark circadian cycle, characterized by a daytime phase (from 07:00 to 19:00 h) with illuminance levels between 150 and 280 lux, and a night time phase (from 19:00 to 07:00 h) during which cribs and incubators were covered with opaque blankets to reduce lighting to less than 20 lux. On the other hand, the control group (n = 21) received conventional management with continuous 24-hour lighting, maintaining a sustained illuminance range between 150 and 280 lux. Following the intervention, total length of hospital stay, cycle duration, days of mechanical ventilation requirement, days of supplemental oxygen use, as well as time to initiation of enteral feeding and time to reach full enteral feeding were evaluated and compared between both groups. For intervention assignment, participants were randomized using block randomization (10 blocks of 4 participants each). The randomization list was generated via Sealed Envelope (Sealed Envelope Ltd. 2024).
1. Preterm infants between 26 and 36 weeks of gestational age 2. Patients admitted to the Neonatal Intensive Care Unit (NICU) of the Hospital General Regional 72,Instituto Mexicano del Seguro Social (IMSS) 3. Informed consent signed by parents or legal guardians
1. Lethal congenital malformations 2. Trisomies 3. Structural defects or malformations