The Role of Cardiovascular and Inflammatory Markers in Elucidating the Etiology of Respiratory Distress in the Newborn

INTRODUCTION: Respiratory distress is at the top of the reasons for admission to the neonatal intensive care unit. This study aims to investigate the role of cardiovascular markers, such as N-terminal pro-brain natriuretic peptide (NT-proBNP), asymmetric dimethylarginine (ADMA) and an inflammatory marker interleukin-6 (IL-6) in elucidating the etiology of respiratory distress, severity of disease and early morbidity.
METHODS: Infants born at ≥32 gestational weeks in our hospital with Downes scores >5 between January 2014-June 2014 and admitted to the neonatal intensive care unit because respiratory distress were enrolled. Blood samples were obtained for this study, Pro-BNP, IL-6 and ADMA levels and Downes scores were calculated at the hospital admission and also 48-72 hours later. Gestational age-matched newborns without respiratory distress and congenital heart disease constituted the control group. Demographic data, medical treatments, type and duration of respiratory support and duration of admission were recorded.
RESULTS: A total of 95 infants were enrolled in this study. Fifty- three (75.7%) of them had transient tachypnea, 9 (12.8%) of them had respiratory distress syndrome and 8 (11.4%) of the patients diagnosed as neonatal pneumonia. The control group consisted of 25 healthy infants. There was no statistically significant difference between ADMA, proBNP, IL-6 levels on days 1 and 3. ADMA levels were found to be positively correlated with Downes scores, duration of mechanical ventilation and inotrope requirement.

DISCUSSION AND CONCLUSION: There is no single reliable marker that can be used in the differential diagnosis of conditions that arise as the cause of respiratory distress in newborns. Especially on Day 3, ADMA levels may be a guide in determining the severity of the disease since it is associated with inotrope need and prolonged respiratory support requirements.