Bronchopulmonary dysplasia in very low birth weight infants.

OBJECTIVE: The developments in newborn care have enabled many more very low birth weight premature infants to live. The aim of our study was to determine the risk factors for bronchopulmonary dysplasia (BPD) development by evaluating mild and moderate/severe BPD in extramural neonates with a birth weight <1501 g.
METHODS: A case-control study was conducted between January 1, 2004- December 31, 2006 at the Dr. Sami Ulus Children's Hospital Neonatal Intensive Care Unit. Patients with BPD and without BPD were compared. Bronchopulmonary dysplasia was diagnosed and classified according to the Bancalari criteria. One-hundred and six (106) extramural premature infants with a birth weight <1501 g and admitted to the Neonatal Unit in the first three days of life and survived for more than 28 postnatal days were included. Patients with multiple congenital anomalies and complex cardiac pathologies were excluded. The maternal and neonatal risk factors, clinical features, mechanical ventilation treatment were compared. The principal risk factors for BPD development were analyzed and followed by logistic regression test.
RESULTS: The diagnosis was mild BPD in 27 of the 106 patients and moderate/severe BPD in 29. The incidence of BPD was 52.8%. Fifty of 106 patients had no BPD. Analysis of risk factors revealed that gestational age < or =28 weeks (p=0.019), birth weight < or =1000 g (p=0.007), hypothermia (p=0.003), acidosis (p=0.003) and hypotension (p=0.005) at admission, respiratory distress syndrome (RDS) ( p<0.001), mechanical ventilation therapy (p<0.001), surfactant therapy (p=0.005), higher amount of mean fluid therapy on 7(th) days (p=0.008), nosocomial infection (p<0.001), higher amount of mean packed red cell transfusions (p<0.001) and more than two packed red cell transfusions (p=0.033) were risk factors associated with the development of BPD. Multivariant logistic regression analysis showed acidosis at admission (OR 5.12, 95%CI 1.17-22.27, p=0.029), surfactant treatment (OR 7.53, 95%CI 2.14-26.45, p=0.002), nosocomial infections (OR 4.66, 95%CI 1.27-17.12, p=0.02) and PDA (OR 9.60, 95%CI 2.23-41.22, p=0.002) were risk factors increasing the severity of BPD.
CONCLUSION: The most important risk factors for BPD development in our study were RDS and nosocomial infections while the presence of acidosis at admission, surfactant administration, nosocomial infections and the presence of PDA were the most important risk factors regarding BPD severity. Presence of acidosis at admission as a risk factor emphasized the importance of suitable transport conditions for premature infants.