Background: In congenital diaphragmatic hernia (CDH) survivors, failure to thrive is a well-known complication, ascribed to several factors. The impact of lung volume on growth of CDH survivors is poorly explored. Our aim was to evaluate if, in CDH survivors, lung volume (LV) after extubation correlates with growth at 12 and 24 months of life.

Methods: LV (measured as functional residual capacity-FRC) was evaluated by multibreath washout traces with an ultrasonic flowmeter and helium gas dilution technique, shortly after extubation. All CDH survivors are enrolled in a dedicated follow-up program. For the purpose of this study, we analyzed the correlation between FRC obtained shortly after extubation and anthropometric measurements at 12 and 24 months of age. We also compared growth between infants with normal lungs and those with hypoplasic lungs according to FRC values. A p<0.05 was considered as statistically significant.

Results: We included in the study 22 CDH survivors who had FRC analyzed after extubation and auxological follow-up at 12 and 24 months of age. We found a significant correlation between FRC and weight Z-score at 12 months, weight Z-score at 24 months and height Z-score at 24 months. We also demonstrated that CDH infants with hypoplasic lungs had a significantly lower weight at 12 months and at 24 months and a significantly lower height at 24 months, when compared to infants with normal lungs.

Conclusion: We analyzed the predictive value of bedside measured lung volumes in a homogeneous cohort of CDH infants and demonstrated a significant correlation between FRC and growth at 12 and 24 months of age. An earlier identification of patients that will require an aggressive nutritional support (such as those with pulmonary hypoplasia) may help reducing the burden of failure to thrive.