Aim: Absent pulmonary valve syndrome (APVS) is found in 3-6% of patients with Tetralogy of Fallot (TOF).Along with findings of TOF, absence of pulmonary valve tissue results in aneurysmal dilatation of the main and branch pulmonary arteries compressing the trachea, main-stem, and intrapulmonary bronchi Shoe/Boot Covers leading to obstructive airways disease.Our objective was to review pulmonary function tests (PFT) in TOF-APVS patients.Materials and Methods: Eight PFT were performed on five mechanically ventilated TOF-APVS patients in the intensive care unit.
Tidal volume, forced vital capacity (FVC), maximal expiratory flow 25%, resistance and compliance of the respiratory system were measured.Results: Pre-operative PFTs showed markedly elevated airways resistance (R RS ) (median 0.45 cmH 2 O/mL/sec, range 0.17-0.
66) and marked variability of the static compliance of the respiratory system (C RS ) (median 0.6 mL/cmH 2 O/kg, range 0.25-2.6).
Flow-volume loops measured by forced deflation showed flow limitation within the medium to small airways.Post-operative FVC was reduced in four of the five patients (median 46 mL/kg, IQR 42.9 - 48.8 mL/kg).
Patients studied with various levels of positive end expiratory pressure (PEEP) showed improvement in APPLE SAUCE ORG tidal volume and reduced obstruction with PEEP greater than 10 cmH 2 O.For three patients with pre-operative data available, surgical correction resulted in near-normal post-operative C RS and improved, but still elevated R RS (median 0.14 cmH 2 O/mL/sec, interquartile range [IQR] 0.11-0.
31).Conclusion: For our patients with TOF-APVS, airway resistance was elevated.Flow limitation was seen in the medium to small airways with a mild reduction of FVC.PFTs may help guide management of mechanical ventilation for TOF-APVS patients.