Changes in lung volume during spells in children with Tetralogy of Fallot under general anesthesia.

OBJECTIVE

To describe the changes in end-expiratory lung volume and ventilation inhomogeneities during spells in three children with Tetralogy of Fallot.

DESIGN

After approval of the institutional Ethics Committee was obtained, children were included in a study protocol that included the assessment of end-expiratory lung volume and ventilation inhomogeneity, using a sulfur hexafluoride multibreath washout technique at different times before and during the surgical repair of congenital heart disease. Additional parental consent was sought to publish this subseries.

SETTING

Operation theater in a tertiary-care university hospital.

PATIENTS: We report the changes in end-expiratory lung volume and ventilation inhomogeneity in three children undergoing Tetralogy of Fallot repair who spelled before surgical incision. While starting the immediate treatment with phenylephrine and increasing Fio2 to 1.0, we were able to measure respiratory function. During the spell, end-expiratory lung volume decreased and ventilation inhomogeneities increased significantly and only recovered slowly even after return of Sao2 to prespell values.

CONCLUSIONS

These data show the deleterious effect of a spell on respiratory function, which may worsen hypoxemia. The loss in lung volume can have a deleterious additive effect in the presence of a spell, particularly because of the slow improvement after treatment.