Clinical characteristics of bronchopulmonary dysplasia in very preterm infants

With the development of perinatal and neonatal intensive care medicine, the survival rate of very premature infants increases year by year. However, the incidence of bronchopulmonary dysplasia (BPD) increases year by year, which seriously affects the survival prognosis of very premature infants. How to prevent and treat BPD effectively has become the focus of neonatologists. This study aims to provide ideas for the prevention and treatment of BPD in very preterm infants via analyzing the clinical characteristics of BPD.

A total of 472 cases of very premature infants admitted to the Divison of Neonatology, Department of Pediatrics at the Second Xiangya Hospital of Central South University were retrospectively selected and assigned into a BPD group (n=147) and a non-BPD group (n=325) according to the diagnosis of BPD. Clinical data of each group were collected to find out the clinical characteristics of BPD in very preterm infants. Basic information, maternal pregnancy data, laboratory findings, nutritional support, respiratory support patterns and duration, and systemic complications were included.

Compared with the non-BPD group, gestational age, birth weight, head circumference and body length in the BPD group were lower, the Apgar score in 1st min and 5th min and average body weight growth rate were lower (all P<0.05); the ratios of male, very low birth weight (VLBW), and extremely low birth weight (ELBW) in the BPD group were higher than those in the non-BPD group (all P<0.5); the incidence of maternal cervical insufficiency and the rate of using embryo transfer technology in the BPD group were higher than those in the non-BPD group, and the rate of using prenatal hormone in the BPD group was lower than that in the non-BPD group (all P<0.05). The positive rate of sputum culture in the BPD group was higher than that in the non-BPD group (P<0.05), and the white blood cell count, neutrophil ratio, and procalcitonin in the BPD group were higher than those in the non-BPD group (all P<0.05). The period of fasting, minimal feeding, total parenteral nutrition (TPN), and partial parenteral nutrition (PPN) in the BPD group were longer than those in the non-BPD group (all P<0.05). The duration of nasal catheter oxygen inhalation and mechanical ventilation in the BPD group was longer than that in the non-BPD group, and the rates of mechanical ventilation at Day 1, 3, 7, 14, 21 and 28 after birth were higher than those in the non-BPD group (all P<0.05). The incidence of respiratory distress syndrome, apnea of prematurity, respiratory failure, pneumonia, pulmonary hemorrhage, pleural effusion, persistent pulmonary hypertension, hemodynamic patent ductus arteriosus, cytomegalovirus infection, neonatal necrotic enterocolitis, cholestasis, anemia, abnormal blood system, hypothyroidism, retinopathy of prematurity, and internal environment disorders in the BPD group were significantly higher than those in non-BPD group (all P<0.05).

There are significant differences between very premature infants with BPD and those without BPD in general information, maternal history, inflammatory indicators, nutritional support, respiratory support, comorbidities and complication rates. To ensure normal fetal development, reducing the inflammatory reaction of very premature infants, establishing enteral nutrition as early as possible, shortening the time of mechanical ventilation, and reducing the occurrence of complications are beneficial to decrease the incidence of BPD in very premature infants and improve the long-term prognosis of BPD.