Study On The Effect Of A Light Dark Cycle On The Development Of Premature Infants

Background Premature infants are born at <37 weeks of gestational age.There are 15 million premature births per year,accounting for about 11.1% of the world's live births.Although the incidence of preterm infants in China is lower than the world average level,the number of preterm infants ranks the world's second.In NICU,due to the need of medical care,premature infants are often exposed to irregular lighting conditions,lack of suitable rehabilitation and growth environment,which affect their sleep,rest and biological rhythm.In addition,due to the long duration of hospitalization,prolonged exposure to irregular ward lighting may affect the long-term behavior and mental development of premature infants.Therefore,it is very important to create a good environment for hospitalization in preterm infants.At present,it is commonly acknowledged that premature infant should be given Developmental Supportive Care.Simulation of fetal intrauterine environment,set the incubator with a blanket or an incubator cover to provide a dim or dark environment for preterm infants.However,how long should the dim or dark environment last and how to build the normal diurnal cycle of 24 h for preterm infants have not been clarified.It should be paid attention that maternal circadian rhythms can affect the fetus in the womb environment.However,premature infants only simulated uterine environment,without the influence of natural law on the alternation of day and night life activities of the human body,is not acceptable.In view of this,the purpose of this study is to explore the influence of light dark cycle on the growth and development of premature infants through a specific empirical process,as well as to further guide the practice of high quality nursing care of premature infants.Objective In order to promote the development of its own biological rhythms,it is necessary to maintain the circadian rhythm of the external environment of preterm infants.So we need to evaluate the light dark cycle on the impact of premature infant development,enrich related research data and provide the basis for clinical evidence-based medicine.Methods Using the method of stratified semi-random,premature infants meet the inclusion criteria were stratified according to the birth weight(birth weight less than <1500g(very low birth weight infant)and 1500g? birth weight<2500g(low birth weight infant)),and they were also divided into observation group and control group according to the admission time.In order to create a light dark cycle(12-12 hours),the observation group received ward ambient light during the day(07:00-19:00),and wear eye pads at night(19:00-07:00),maintaining the dark environment during the night.The control group was given conventional nursing group,maintaining the 24 hour dark environment with a blanket on the incubator like the uterus,only medical care must be taken in the bright light environment Intervention time started from admission and ended with discharge.The effect of light dark cycle on premature infants development were evaluated.Result1.Physical development:(1)The very low birth weight infant(VLBWI)group,the daily weight gain,weight growth velocity,the average daily weight gain after returning to birth weight,the weight growth velocity after returning to birth weight of the observation group were higher than those in the control group.The weight of observation group in eighth week was higher than that in the control group,the difference was statistically significant.(2)The low birth weight infant(LBWI)group,there was no significant difference in the daily weight gain and weight growth velocity between the observation group and the control group.2.Body temperature(BT)rhythm:(1)The VLBWI group,the observation group and the control group had statistical significance on BT at each time point in the fourth and sixth weeks after admission.Time trend showed that the observation group showed a significant circadian rhythm in fifth weeks,sixth weeks and eighth weeks.BT was low in the morning,peaked in the afternoon and reduced at night.Although there is rhythm in the control group,it was in a state of disorder.There was significant difference between the observation group and the control group in second weeks.(2)The LBWI group,BT was statistically significant at each time point in the first week to the fifth weeks after admission between the observation group and the control group.The observation group showed a significant circadian rhythm in third and fifth week.BT was low in the morning,peaked in the afternoon and reduced at night.Although there is rhythm in the control group,it was in a state of disorder.3.Respiratory function recovery:(1)The VLBWI group,time of oxygen and NCPAP in the observation group were shorter than those in the control group,the difference was not statistically significant.(2)The LBWI group,there was no significant difference in the time of oxygen and NCPAP between the observation group and the control group.4.Severe complications:(1)The VLBWI group,the observation group had less severe complications than the control group.(2)The LBWI group,the incidence of serious complications was similar between the observation group and the control group.5.Hospitalization time and expenses:(1)The VLBWI group,compared with the control group,the total and average hospitalization cost of the observation group were decreased,the corrected gestational age at discharge was slightly lower than that of the observation group,but the difference was not statistically significant.Conclusion(1)Light dark cycle is conducive to the physical development of very low birth weight infants.It can help them recover respiratory function,reduce the occurrence of serious complications,reduce the economic burden of the family members of the children,.(2)The maturity of premature infants has an influence on the occurrence of the post birth biological rhythm;(3)Light dark cycle plays an important role in regulating the body temperature of premature infants.