Pulse oximetry during cardiac catheterization in children with congenital heart disease.

One hundred and five children with congenital heart disease were monitored by pulse oximetry during cardiac catheterization. Excellent correlation (r = 0.95) was found between oxygen saturation values obtained with pulse oximetry and those obtained from arterial blood in 133 data pairs. This correlation was described by the regression equation y = 0.91x + 8.1. The correlation was also excellent in 47 data pairs with saturation values of less than 90% (r = 0.94, y = 0.93x + 6.0) from 36 cyanotic children. The clinical usefulness of pulse oximetry in the early recognition of decreased pulmonary blood flow or partial airway obstruction was demonstrated. Early diagnosis of changes in oxygenation was especially helpful in children with cyanotic congenital heart disease, in whom small changes in arterial oxygen tension may cause large changes in oxygen saturation.