Abstract
Objective Administering surfactant timely and appropriately is important to minimize lung injury
but remains challenging in preterm neonates with respiratory distress syndrome. The
published literature supports that lung ultrasound (LUS) score can predict surfactant
need. Neonatal LUS scanning specification and parameter setting guidelines have been
recently published for standardization. However, variations in scanning protocols
and machine settings hinder its clinical implementation widely. This observational
study aims to internally validate the suggested LUS protocol in a neonatal intensive
care unit to establish a correlation between LUS scores and surfactant need as the
first step of integrating LUS in the clinical practice.
Study Design LUS was performed on 40 eligible preterm neonates within 3 hours after birth or before
surfactant administration between May 2020 and March 2021. The neonates were between
27 and 32 weeks' gestational age, and all had respiratory distress. Neonates with
known congenital anomalies were excluded. A high-frequency linear probe was used to
obtain LUS images from six lung zones which were scored using a 0 to 3 system, yielding
a maximum of 18 points. Treating physicians were blinded to the LUS score. Receiver
operating characteristic analysis determined the optimal LUS score cut-off for predicting
surfactant need.
Results Fifteen of the 40 neonates (38%) required higher oxygen fraction and received surfactant.
In our cohort, an LUS score ≥10 was identified as the optimal cut-off for predicting
surfactant need, with a sensitivity of 80% and specificity of 84%. The area under
the curve was 0.8 (p = 0.0003). LUS predicted surfactant need at a median of 3.5 hours earlier than traditional
clinical decision (p < 0.0037).
Conclusion LUS is a helpful adjunct for predicting surfactant need in preterm neonates. This
study describes an approach to implement the LUS protocol and score for clinical decision-making
in the clinical practice.
Key Points
LUS is a helpful adjunct for predicting surfactant need in preterm neonates.
Machine setting variation and probe selection may affect LUS image and score.
LUS score should be validated at the local unit before clinical implementation.
Keywords point of care ultrasound - lung ultrasound - lung ultrasound scores - preterm neonates
- respiratory distress syndrome - surfactant
