Evaluation of Lung Functions in Preschool-Children Diagnosed with Transient Tachypnea of the Newborn by Impulse Oscillometry System

Background: Transient tachypnea of the newborn (TTN) is the most common self-limiting respiratory distress in neonates. There are increasing data suggesting that TTN may be a risk factor for childhood disease. Aim: To evaluate lung functions in preschool-children diagnosed with TTN using Impulse Oscillometry System (IOS) for the presence of respiratory morbidity. Methods and Patients: In this prospective study, preschool-children diagnosed with TTN and age-matched healthy children were defined as TTN-group and control group, and performed IOS. Resistance (R5-R20), reactance (X5-X20) resonant frequency (Z5), and reactance area (AX) IOS values were compared in both groups and in TTN-subgroups. Statistical findings were presented as median (IQR). Results: A total of 51 preschool-children and 101 healthy controls participated in study. The rate of asthma diagnosis and wheezing attacks in TTN-group was found 30.8% and 38.5%, respectively. However, R5 minus R20 was significantly higher, X10, X15 values were significantly lower in TTN-group than those in controls. Additionally, R5 minus R20 and AX values were significantly higher in late-preterm TTN-subgroup as compared to term TTN-subgroup. AX was significantly higher in TTN-group supported with nasal ventilation. R5, R10, R15 and R20 were significantly higher in TTN-subgroup with history of maternal asthma compared to TTN-subgroup without that history. R5, R10, R15 and Z5 were significantly higher and X10, X15, X20 were significantly lower in TTN-subgroup with passive smoking compared to TTN-subgroup without passive smoking. Conclusion: Our findings showed peripheral airway obstruction, a known finding in asthma, among preschool-children diagnosed with TTN compared to healthy controls.