Evaluation of double lung point sign as a marker for transient tachypnoea of the newborn in preterm

Purpose
The study was conducted to diagnose transient tachypnoea of the newborn (TTN) in the early stage using ultrasonography and to estimate the sensitivity and specificity of double lung point (DLP) sign in diagnosing TTN.

Material and methods
The study population included premature neonates with respiratory distress, admitted in the neonatal intensive care unit from December 2017 to June 2019, who fulfilled the inclusion criteria. A total of 100 patients were included in the study, and they underwent lung ultrasonography within 6 hours of birth. Inclusion criteria were as follows: preterm babies born < 37 weeks of gestation presenting with respiratory distress within 6 hours, clinically diagnosed with TTN and other causes like respiratory distress syndrome and pneumonia. Term neonates and neonates with congenital malformations and trauma were excluded from the study. Preterms with respiratory distress were enrolled in the study. Based on the clinical findings and laboratory investigations, clinical diagnosis was made by the paediatrician. After obtaining informed consent, ultrasonography of bilateral chest was performed using a Philips HD7 XE and a Sonoscape S2 portable ultrasound machine with a linear transducer (6-12 MHz) within 6 hours of birth.

Results
The mean gestational age was 33.0 ± 1.9 weeks. Double lung point sign was present in 55 preterm neonates in our study. It was most common in bilateral posterior lung fields. The sensitivity and specificity of DLP in diagnosing TTN was 85% and 100%, respectively.

Conclusions
It was found in our study that double lung point sign is the primary ultrasonographic characteristic of TTN, and ultrasonography can almost accurately diagnose TTN in early stages.