[Functional respiratory disorders in children with left-to-right shunt]

The respiratory function of 19 children aged from 2 months to 9 years old with a cardiac lesion giving a left-to-right shunt was studied and analysed with respect to the hemodynamic disturbance. Respiratory function tests (RFTs) included measurement of functional residual capacity (FRC), the partial pressure in oxygen (Pa 02) on arterialised blood taken from the ear lobe, dynamic pulmonary compliance (CI dyn.) and total pulmonary resistance (RI). FRC and RI were not significantly modified. On the other hand, CI. dyn. was low (-31.2 +/- 22.9%, p less than 0,001) as were the CI. dyn. CFR ratio (-25.5 +/- 20.9%, p less than 0.001) and the Pa 02 (-7.6 +/- 12.7% p less than 0.02). There was a significant correlation between the reduction of CI. dyn. and mean pulmonary arterial pressure (PAP) and the increase in the pulmonary blood flow. In addition, a significant correlation was also found between the reduction in Pa 02 and the PAP and increase in pulmonary blood flow. These results show that cardiac lesions with left-to-right shunts give rise to diffuse changes in respiratory function and are discussed in the light of the abnormalities in pulmonary development previously described in pulmonary biopsy of patients with left-to-right shunts. The value of RFTs in the surveillance of patients with left-to-right shunts is underlined.