Thoracic electrical bioimpedance in preterm newborns with and without respiratory distress syndrome: an exploratory observational study.

Abstract

To test the hypothesis that thoracic fluid content (TFC) by thoracic electrical bioimpedance would be higher in preterm infants with respiratory distress syndrome (RDS) both at birth and in the first 48 h of life than in those without RDS and that TFC measured at birth would be associated with RDS diagnosis and need for surfactant. Cross-sectional exploratory observational study including infants ≤ 34 weeks of gestation admitted to two level three NICUs. TFC, clinical, and respiratory data were recorded at 5 timepoints: within the first 2 h of life, before surfactant therapy, and at 4, 12, 24, and 48 h of life. TFC was compared between infants with and without RDS. A ROC curve was calculated to assess the association between TFC at birth and the need for surfactant. TFC was higher in infants with RDS than in infants without RDS at all timepoints. The ROC AUC of TFC measured at birth for the need for surfactant was 0.817 (95% CI 0.64-0.93, p < 0.001); a TFC cut-off of 20.4 1/KOhm/Kg yielded a sensitivity of 83% and specificity of 80% for the need for surfactant. Conclusion: TFC in the first 48 h of life was higher in preterm infants with RDS than in infants without RDS. TFC measured within the first 2 h of life had a good association with the need for surfactant. What is known: • Thoracic electrical bioimpedance can be used to measure thoracic fluid content (TFC) non invasively in newborns What is new: • TFC was higher in premature newborns with respiratory distress syndrome (RDS) that in those without RDS in the first 48 h of life. A high TFC in the first 2 h was associated with the need for surfactant.