Role of Lung Ultrasonography in Prediction of the Seveity and the Need for Surfactant Administration in Neonates With Respiratory Distress Syndrome
Role of Lung Ultrasonography in Prediction of the Seveity and the Need for Surfactant Administration in Neonates With Respiratory Distress Syndrome
We aim to identify the diagnostic role of a lung ultrasonography (LUS) score to predict the
 severity and the need for surfactant therapy in newborns with respiratory distress syndrome
 (RDS), and to compare it with a chest X-ray score.
Respiratory distress syndrome (RDS) is a common problem in preterm infants. This condition is
 caused by deficiency of pulmonary surfactant in an immature lung and is related to morbidity
 and mortality in preterm infants. The incidence of RDS increases with the decreasing of
 gestational age (GA). The National Institute of Child Health and Human Development Neonatal
 Research Network reports a 93 percent incidence of RDS in a cohort of extremely preterm
 infants (GA 28 weeks or below)1. Although the risk is lower, RDS occurs even in a significant
 number of late preterm infants2. Diagnosis of RDS is based on clinical manifestations,
 arterial blood gas and chest X-ray findings. Chest X-ray is considered a first-line imaging
 test for diagnosis of RDS2. Chest X-ray findings, however, are not related to the respiratory
 prognosis3 .

 Recently, lung ultrasonography (LUS) has been used in critically ill patient and it has
 become an important tool for neonatologists4. Specific LUS patterns have been described for
 typical neonatal respiratory conditions such as RDS5, transient tachypnea of the newborn
 (TTN)6, meconium aspiration syndrome (MAS)7, and pneumothorax8,9.As reported in The Consensus
 Conference on lung ultrasound, both LUS and chest X-ray are accurate in the diagnosis of RDS
 and TTN in neonates10.

 Surfactant replacement therapy is crucial in the management of RDS. Recent guidelines
 recommend to treat affected babies with early nasal continuous positive airway pressure
 (nCPAP) and early selective surfactant administration10. The European Association of
 Perinatal Medicine and the American Academy of Pediatrics advise surfactant administration
 when oxygen requirement increases despite early nCPAP treatment11,12. Some studies have
 recently highlighted the usefulness of LUS in predicting neonatal intensive care unit
 admission or the need for mechanical ventilation13,14 or nCPAP failure15. Many scores based
 on LUS findings have proved their reliability in adult critical care16,17. In the neonatal
 field few studies presented chest X-ray derived scores18 or directly compared LUS with chest
 ray. There are no data, to our knowledge, that compare the accuracy of LUS with chest X-ray
 in predicting the need for surfactant administration in infants with RDS18-20.

 Basically, each lung was divided into 3 areas (upper anterior, lower anterior, and lateral)
 and examined using a linear microprobe through both transverse and longitudinal scans. For
 each lung area, a 0- to 3-point score was given (total score ranging from 0-18). The LUS
 score encompassed signs typical of TTN and RDS21-22 . and described the total spectrum of
 possible conditions (a normal aerated lung, an interstitial pattern, an alveolar pattern, and
 consolidation). In details, the LUS score was assigned as follows:0 indicates A-pattern
 (defined by the presence of the only A-lines); 1, B-pattern (defined as the presence of ≥3
 well-spaced B-lines); 2, severe B pattern (defined as the presence of crowded and coalescent
 B lines with or without consolidations limited to the subpleural space); and 3, extended
 consolidations. A-lines represent reflection of pleura due to ultrasound diffusing through an
 airfilled lung; B-lines are due to fluid filling the interstitium (and the alveolar space if
 they become confluent)23,24.
Inclusion Criteria:

 -  • Gestational age < 28 weeks.

 -  Birth weight <1000 grams.

 -  Newborns diagnosed only with RDS clinically and by chest X-Ray findings

 Exclusion Criteria:

 -  • Gestational age ≤ 28 weeks.

 -  Birth weight ≤ 1000 grams.

 -  Newborns with congenital anomalies.