Evaluation of Serial Lung Ultrasound Data After Surfactant Treatments Applied With Different Methods in Preterm Babies

In the neonatal intensive care unit, lung ultrasound was first used for the diagnosis of neonatal respiratory distress syndrome (RDS) by Avni et al. in 1990. Following this, lung ultrasound rapidly became widespread in neonatal intensive care units and was seen as a potential alternative to chest X-rays. It is now frequently used in cases of RDS, transient tachypnea of the newborn, pneumonia, and pneumothorax. Lung ultrasound has high specificity, sensitivity, positive predictive value, and negative predictive value. It is performed quickly at the bedside, allowing for rapid diagnosis and timely intervention.

Respiratory distress syndrome is one of the most common causes of morbidity and mortality in preterm infants. It results from a surfactant deficiency in the lungs secondary to preterm birth. Early diagnosis and timely administration of intratracheal surfactant, which is the only definitive treatment, are crucial. The diagnosis has traditionally relied on chest X-rays, but with recent advancements, lung ultrasound has also become a diagnostic tool. In addition to diagnosing RDS, lung ultrasound plays a critical role in its differential diagnosis, severity classification, and management in neonates.

Different methods can be used for the intratracheal administration of surfactant in the treatment of neonatal respiratory distress syndrome. Surfactant can be administered through an endotracheal tube in intubated infants. In non-intubated infants, two commonly accepted and frequently used methods are available. The first method involves intubating the infant, administering intratracheal surfactant, and then extubating them back to nasal respiratory support (ENSURE method). The second method involves delivering surfactant via a thin catheter (5F) directly into the trachea while the infant remains on existing nasal respiratory support, without disconnecting them from it (LISA method). Both of these methods are frequently used in neonatal intensive care units, and multiple studies comparing them indicate no clear superiority of one over the other.

Many studies utilizing lung ultrasound incorporate lung ultrasound scoring systems. The first neonatal lung ultrasound score was defined by Brat et al. Each lung is divided into three regions (upper anterior, lower anterior, and lateral), and each region is assigned a score from 0 to 3:

0 points: Defined by the presence of only A-lines.