Digital stethoscope technology to evaluate breath sounds in preterm neonates with respiratory distress syndrome.

Abstract

Background: Respiratory distress syndrome (RDS) is the most common indication for respiratory support within preterm neonates. While digital stethoscopes (DS) have been used to evaluate the breath sounds of self-ventilating neonates, they have not previously been used to study the breath sounds of preterm neonates with RDS on respiratory support. Method(s): A commercially available DS and smartphone software was used to record breath sounds of preterm neonates born at gestational age less than 32 weeks on day two of life. The recordings were filtered for noise reduction and spectral analysis performed to assess parameters including total power and the proportion of power in the low (100-200 Hz), medium (200-400 Hz) and high (400-800 Hz) frequency ranges. Acoustic characteristics were compared between neonates who had received surfactant replacement therapy (SRT) and those who had not. Result(s): Fifty-five neonates were studied. After exclusions due to background noise, crying or insufficient breath sounds, 17 neonates who received SRT (median (IQR) gestational age 26.3 (3.9) weeks, birth weight 766 (527.5) grams), and 16 neonates who did not receive SRT (31.1 (1.7) weeks, 1301 (643.2) grams) were analysed. Neonates who received SRT had significantly increased total power and proportion of power in the 400-800 Hz range Conclusion(s): There are differences in the acoustic characteristics of breath sounds between preterm neonates who received SRT and those who did not, likely due to differences in infant size and mode of respiratory support.