Combined Lung Ultrasounds and Transthoracic Electrical Bioimpedance in Preterm Infants With Respiratory Distress.

Respiratory distress syndrome (RDS) is among the most common complications of preterm birth, and typically becomes manifested soon after birth. A failure of the rapid reuptake of fetal lung fluids after birth, with subsequent liquid retention in the alveolar space, together with the deficit of surfactant proteins ensuing from lung immaturity represent the leading mechanisms for the development of RDS, which may require different levels of respiratory support. An increasingly used method for the evaluation of the neonatal lung is pulmonary ultrasound, which allows assessing alveolar fluids and other pathological conditions in a non-invasive manner, and has been shown to predict the need for respiratory support and for surfactant administration in preterm infants with RDS. However, this method requires specific training, is operator-dependent and does not provide a trend able assessment over time. Transthoracic electrical bioimpedance (TEB) allows continuous and non-invasive monitoring of static and dynamic thoracic fluids. It has been recently introduced in neonatal clinical practice to assess such hemodynamic parameters as cardiac output and also quantifies static thoracic fluids contents (TFC). This method provides continuous and non-operator dependent data on the pulmonary fluid status over time and does not require specific training. The combination of lung ultrasound with TEB could open to new diagnostic and prognostic perspectives in preterm infants with RDS.