Background: Tracheo-oesophageal fistula (TOF) and oesophageal atresia (OA) are congenital anomalies commonly associated with pulmonary complications during early childhood. This study investigated the role of the forced oscillation technique (FOT) in assessing lung function in young children with repaired TOF/OA.
Methods: Forty children with repaired TOF/OA of median (range) age 8.0 (3.3-10.6) years, and 20 healthy children without TOF aged 6.1 (3.1-10.8) years were studied. FOT measurements were attempted in all subjects and spirometry only in those 6 years and above. Resistance and reactance (both hPasL(-1)) at 6 Hz (Rrs6 and Xrs6, respectively) and 8 Hz (Rrs8 and Xrs8) measured using FOT, and forced expired volume in 1 sec (FEV(1)), forced vital capacity, functional residual capacity, total lung capacity, and residual volume (all L) obtained from spirometry or plethysmography were compared with reference values and expressed as z-scores.
Results: Technically acceptable measurements of Rrs6, Rrs8, Xrs6, Xrs8, Fdep, and Fres were obtained in 37 children with TOF and 20 healthy children without TOF, respectively. Those with TOF had significantly higher mean (SD) z-scores for Rrs6 [0.99 (0.75)] versus healthy children without TOF [0.31 (0.69)] and lower mean (SD) z-scores for Xrs6 [-1.04 (1.07)] versus healthy children without TOF [-0.34 (0.83)]. Spirometry was successful in 24 of the 29 with TOF in whom it was attempted and all healthy children without TOF. Mean (SD) z-score for FEV(1) was significantly lower in those with TOF [-0.86 (1.13)] versus healthy children without TOF [0.67 (0.54)]. z-Scores for Rrs6 and FEV(1) were significantly correlated (r = -0.49; P = 0.003).
Conclusions: Children with repaired TOF have diminished lung function compared with healthy children. FOT is sensitive and correlates well with standard spirometry. It can be used to measure lung function in younger children when spirometry is difficult to perform and should be considered as an objective method for monitoring clinical progress in young children with TOF.