[A study of aspiration in infants with recurrent pneumonia by Barium swallow examination using different concentrations of barium].

We conducted barium swallow examinations using different concentrations of barium sulfate suspension (10, 30, 60 w/v%) in infants with recurrent pneumonia. Aspiration of swallowed barium into the airway was demonstrated in 43 of 54 infants (44 of 56 examinations). Of these, 22 infants had no neurological or anatomical abnormality. In comparing the degree of aspiration and the barium concentration, it was found that the higher the concentration of barium, the less severe the degree of aspiration tended to be. There was no infant in whom thicker barium aggravated aspiration. The difference in the degree of aspiration was considered to be attributable to difference, in the viscosity of barium. The results of our study showed aspiration to the airway was more frequent than previously reported, and occurred even in infants without any other abnormality. The detectability of aspiration was dependent on the concentration of barium sulfate suspension. Because the viscosity of conventionally used milk is identical to that of 10-20 w/v% barium, 10-20 w/v% barium should be used in barium swallow examinations for infants with recurrent pneumonia.