Post-operative lung function impairment in infants with congenital diaphragmatic hernia

Background: Advances in management of congenital diaphragmatic hernia (CDH) have improved mortality rates but with a risk of increased pulmonary morbidity. The prognosis remains difficult to predict owing to the lack of adequate methods. Methods: Single photon emission computed tomography (SPECT) was performed to measure the regional distribution of ventilation (V) and perfusion (Q) in 23 infants at the mean age of nine months to quantify the degree of lung function impairment. V and Q were traced with 5 MBq Technegas and technetium-labelled albumin macro-aggregates, respectively. Clinical variables were evaluated by a pediatric pulmonologist. Results: The SPECT results differed significantly among patients. Some had almost no V and Q on the ipsilateral side, resulting in only one functional lung, while others had almost normal V-Q distribution in both lungs. All infants requiring patch and/or ECMO have moderate to severe V-Q abnormalities. The clinical evaluation did not always reveal the degree of lung function impairment. Conclusions: Post-operative evaluation in infants with CDH reveal a wide variety in V-Q abnormalities. This variation in lung function was not evident from other investigations. Quantifying the degree of lung function impairment provides important clinical information for decisions during patient management and follow-up. Fig 1. SPECT results for an infant with left-sided CDH with moderate V-Q distribution.