What type of contrast agent should be requested first in patients with suspected upper GI perforation?
In patients with known or suspected perforations of the pharynx, esophagus, or duodenum, an ionic water-soluble contrast agent such as diatrizoate meglumine (Gastroview or Gastrografin) should be used initially. This type of agent is readily absorbed from the soft tissues of the neck, mediastinum, and peritoneal cavity. This type of agent, if aspirated, has the theoretical potential to cause pulmonary edema because it is hyperosmolar and draws fluid into the lungs. If aspiration is a likely possibility, the radiologist may start with a nonionic water-soluble contrast agent that is either only mildly hyperosmolar (iohexol [Omnipaque for Oral Use]) or iso-osmolar. Other radiologists start with barium if a perforation of the pharynx or esophagus is suspected, and there is a high risk of aspiration because barium in the soft tissues of the neck or mediastinum is relatively harmless. Barium entering the peritoneal cavity from a gastric or duodenal perforation can potentially cause mild barium peritonitis. This situation is not as serious, however, as barium entering the peritoneal space from a colonic perforation. The combination of barium and feces entering the peritoneal space during a barium enema has a much greater likelihood of causing peritonitis and has a high mortality rate.
