Meta Analysis Of The Efficiency And Safety Of Vitamin A In Preventing Bronchopulmonary Dysplasia In Premature Infants

Bronchopulmonary dysplasia(BPD)is a kind of chronic lung disease.It is one of the complications that seriously affect the prognosis of premature infants.It often occurs in preterm infants who receive constant oxygen for over 28 d after birth.It has been found that the occurrence of BPD was related to children birth weight,gestational age,slow growth,long duration of hospitalization,intrauterine infection,inflammation and mechanical ventilation or oxygen treatment.BPD has been seriously affected the infant's normal development of the nervous system,behavior intelligence,movement,audio-visual,especially the respiratory system.The lung function of children with BPD,including lung ventilation,ventilation and alveolar diffusion function,is significantly lower than that of normal neonates with same gestational age.Although the respiratory care has been improved In the past 30 years,the incidence rate of BPD was not significantly reduced,and it is still one of the main reasons of premature death and poor prognosis.There is no effective treatment at present.A number of prospective studies have proved that the application of vitamin A can significantly reduce the incidence of BPD and mortality,however the results are not entirely consistent.The current research on vitamin A in the prevention of BPD are mostly single center study,and the project needs for research.Studies of multi center and large samples are required to verify the efficacy and safety of vitamin A to guide clinical treatment.Objective:This study uses systemactic elvation method and meta analysis to integrate data of randomized controlled trials of vitamin A in preventing bronchopulmonary dysplasia,aiming to provide evidence-based medical evidence for prevention and treatment of chronic lung diseases in premature infants.Methods:Computer retrieval Pub Med,American Medical Index(Medline),Holland Medical Abstracts(EMBASE),China CNKI,Wan Fang,VIP,retrieve the date ranging from the building date to 2017 05,and at the same time,track references,trying to screen out articles or journals related to Vitamin A and the Occurrence and Prognosis of BPD.The bias risk assessment of RCT was carried out according to the Cochrane evaluator's manual 5.02.Review Mananger 5.3 software was used for statistical analysis.Key words included vitamin A,chronic lung disease(CLD),bronchopulmonary dysplasia(BPD),lung injury and Chinese term vitamin A,chronic lung disease,bronchopulmonary dysplasia,and lung injury,combining with the characteristics of different database,corresponding retrieval type are formulated.Results:1 retrieval resultsAfter searching,the researcher found 507 articles: 485 English articles(Pub Med 160,Medline 80,Embase 245),22 Chinese articles(Chinese How Net 6,VIP 4,Wanfang 12).Among these 507 papers,153 repetitive articles were eliminated,322 were excluded due to the inconsistency of its headlines and abstracts.Moreover,25 articles were excluded by reading the full text,including one drug delivery mode,which was injected into the trachea.In the end,7 articles were included,and 1164 cases were accepted.2 literature quality evaluationThe risk of bias was evaluated in 7 randomized controlled studies.4 studies described how the random sequence generated,3 studies explained the distribution of hidden method,5 studies applied blinded experimenter with double-blind assessment and outcome of participants,and 3 studies describes the situation and reasons of lost.The funnel map,which included the BPD incidence and the mortality as the outcome index,was basically symmetrical and no significant bias was published.3 summary analysis3.1 The relationship between vit A and BPD incidence:The incidence of BPD was reported in all 7 items of RCT.The heterogeneity test was P = 0.11,I2 = 42%.The homogeneity of each study was better,and the fixed effect model was used.According to the results of Meta analysis P = 0.07,95%CI~ 0.89[0.17,1.01],which suggested that vit A had no obvious preventive effect on the incidence of BPD.3.2 The results of subgroup analysis of vit A and the incidence of BPD:In the thesis,the high quality researches refers to those literatures that are evaluated as relatively high antides by the quality evaluation criteria expressed in the Cochrane evaluator manual.Subgroup analysis was carried out on birth weight,race,dosage,dosage and high quality research.Results showed that the application of vitamin A had no significant preventive effect on BPD.3.3 Safety outcome:It has no adverse reactions were reported in all the included literature,and the use of vitamin A was safe and feasible.3.4 The relationship between vit A and mortality:The mortality was reported in 6 RCT.The heterogeneity test was P = 0.61,I2 = 0%.The homogeneity of each study was better,and the fixed effect model was applied.The results of Meta analysis showed that P = 0.01,95%CI ~0.69[0.51,0.92],which suggested that the use of vit A could significantly reduce the mortality rate.3.5 The results of subgroup analysis of vit A and the mortality rate:Subgroup analysis was conducted on birth weight,race,drug delivery,dosage,and high quality research.The results of Meta analysis revealed that intramuscular injection of vit A group could significantly reduce the incidence of mortality.The rest of the different birth weight,different races,different doses,and high quality studies showed that the use of vit A had no significant preventive effect on mortality.Conclusion:1.The use of vit A has no significant correlation to the prevention of BPD in preterm infants.2.The use of vit A is safe and no adverse reaction occurs.3.The use of vit A can reduce the short-term mortality of preterm infants and improve the outcome of premature infants.