Risk factors for bronchopulmonary dysplasia in extremely preterm infants / 中华围产医学杂志

ABSTRACT

Objective To investigate the risk factors for bronchopulmonary dysplasia (BPD) in extremely preterm infants and to provide clinical evidence for early prevention.Methods Clinical data of extremely preterm infants born at less than 28 gestational weeks,who were treated in the Neonatal Intensive Care Unit of Shenzhen Maternity & Child Healthcare Hospital between January 1,2014 and December 3 l,2016 and survived over 28 days were studied retrospectively.These infants were divided into BPD (n=104) or non-BPD group (n=l 1) according to their final diagnosis.Two independent samples t-test or Chi-square test was used for statistical analysis.Risk factors for BPD were analyzed by univariate analysis and multivariate logistic regression.Results A total of 115 extremely preterm infants were enrolled in this study and 90.4％ (104/115) of them were diagnosed with BPD.Mild,moderate and severe cases of BPD accounted for 73.7％ (70/95),25.3％ (24/95) and 1.1％ (1/95) of all BPD cases respectively,except for nine cases who was referred to other hospitals,ceased for treatment or died before corrected age of 36 weeks.The univariate analysis showed that the BPD and non-BPD groups had significant differences in the following aspectsgestational age [(26.6± 1.0) vs (27.6 ± 0.2) weeks,t=-3.553],birth weight [(918.7 ± 169.1) vs (1 105.0 ± 121.1) g,t=-9.012],length of hospital stay [(85.2 ± 32.4) vs (56.1 ± 9.0) d,t=6.974],1 min Apgar score＜8 [62.5％ (65/104) vs 2/11,x2=6.528],methods of neonatal resuscitation in deliver room (x2=21.049),administration of pulmonary surfactant [88.5％ (92/104) vs 5/11,x2=10.869],invasive ventilation [80.8％ (84/104) vs 2/11,x2=13.294],times of invasive ventilation [1.0(1.2-2.0) vs 0.0 (0.0-0.0) times,Z=3.960],duration of the first invasive ventilation [12.0 (2.0-24.0) vs 0.0 (0.0-0.0) h.Z=3.997],total length of all invasive ventilations [18.0 (2.3-163.5) vs 0.0 (0.0-0.0) h,Z=4.405],duration of oxygen therapy [51.5 (40.0-70.8) vs 13.0 (7.0-25.0) h,Z=5.113] and administration of vasoactive agents during the first 24 hours after birth [52.9％ (55/104) vs 2/11,x2=4.792],which indicated that they were risk factors for BPD in extremely preterm infants.Results of the multivariate logistic regression analysis showed that prolonged length of oxygen therapy [OR=1.276 (95％CIl.107-1.472),P=0.001] was the risk factor,while high birth weight [OR=0.993 (95％CI0.986-0.999),P=0.037] and reduced usage of invasive ventilation [OR=0.079 (95％CI0.013-0.471),P=0.005] were protective factors against BPD.Conclusions The incidence of BPD which can be influenced by many factors is really high in extremely preterm infants.Avoiding invasive ventilation,shortening the duration of oxygen therapy and adopting a comprehensive and standardized treatment at an early stage may decrease the incidence of BPD.