Blood Gas pH and Pulmonary Response to the Inhalation of Low Osmolar Contrast Media Iopamidol and Ioxaglate

Effects of inhalation of diluted Iow-osmolar ionic ioxaglate and nonionic iopamidol 200 water-soluble radiographic contrast media on neonatal pig lung were evaluated. Our purpose was to assess the suitability of these substances for the radiologic investigation of upper gastrointestinal problems in human neonates in whom aspiration may occur.We used two-week-old baby piglets weighing 2.5-3.5 kg as the experimental model because they are similar in weight and size to a human neonate. The effects of intratracheal instillation of isosmolar contrast media were evaluated using the parameters of (1) blood gas exchange, (2) clinical status, (3) radiology, and (4) histopathology.The piglets showed no clinical or radiologic abnormality; blood gas exchange, initially impaired, rapidly returned to normal. Long-term (four days) follow up showed mild, self limiting but persistent infiltrates in the lungs at histology. We conclude that these diluted contrast media are suitable for upper gastrointestinal examination in neonates.