Pleural line thickness reference values for preterm and term newborns

Area of Science:

• Neonatal Medicine
• Pediatric Imaging
• Ultrasound Diagnostics

Background:

• The pleural line in lung ultrasound (LUS) is an artifact whose thickness correlates with lung pathology.
• Currently, there is a lack of published data on normal pleural line thickness (PLT) values in newborns.

Purpose of the Study:

• To establish and describe normal pleural line thickness (PLT) values in both term newborns (TN) and preterm newborns (PTN).

Main Methods:

• Recruited healthy, eupneic term and preterm newborns (under 34 weeks gestation) within the first 24 hours of life.
• Excluded newborns with any signs of respiratory distress.
• Performed LUS in four specific areas (upper anterior, lower anterior, lateral, posterior) to measure PLT.
• Assessed intraobserver and interobserver agreement using intraclass correlation coefficient (ICC) and kappa coefficient.

Main Results:

• Included 23 TN (median gestational age 39 weeks) and 23 PTN (median gestational age 31 weeks).
• Median PLT values in both groups were below 1 mm.
• No significant differences in PLT were found between TN and PTN across most locations, except the left lower anterior field.
• High intraobserver agreement (ICC 0.77-0.78) and interobserver agreement for defining a thin pleural line (<1 mm) were observed.

Conclusions:

• Term newborns and asymptomatic preterm newborns exhibit similar pleural line thickness (PLT) values.
• The established normal range for PLT in healthy newborns, as measured by LUS, is less than 1 mm.