Shock and noncardiogenic pulmonary edema following meglumine diatrizoate for intravenous pyelography

Anaphylactoid reaction and non-cardiac pulmonary edema following intravenous contrast injection

A case of severe anaphylactoid reaction following injection of intravenous contrast is described, and a discussion of the treatment of severe allergic reactions follows. The patient's presentation was unusual in that she rapidly developed massive non-cardiac pulmonary edema as the primary symptom, along with hypotension and hypokalemia, a syndrome similar to adult respiratory distress syndrome. The development of the reaction along with the unusual presentation is discussed and a detailed discussion of the generalized treatment of anaphylactoid and anaphylactic reactions is presented. Additionally, several errors in management that may have delayed resolution of the symptoms and prolonged the period of instability in the patient's condition are discussed and critiqued.

Pulmonary edema following high intravenous doses of diatrizoate in the rat. Effects of corticosteroid pretreatment

Serious adverse reactions to intravenous contrast media are rare but of major concern. Corticosteroids are the most commonly used drugs for prophylaxis but there is little documentation of their effectiveness. Controversy also exists about the optimum regime for these drugs. A rat model was used to evaluate the effect of methylprednisolone pretreatment for contrast media-induced pulmonary edema. Rats were given 40 mg methylprednisolone/kg intravenously at various time intervals before the intravenous injection of a high dose of diatrizoate (6 g I/kg). The combination of one dose of methylprednisolone at 24 hours plus another dose at 0.5 hours was the only regimen that caused a significant reduction in the degree of pulmonary edema induced by contrast media. This result provides support for the clinical regimen utilizing iterated doses of corticosteroids over a prolonged period of time.

Pulmonary edema induced by contrast medium. A comparative investigation in the rat following high intravenous doses of one ionic (diatrizoate) and non-ionic (metrizamide) contrast medium

Monomeric ionic contrast media are known to induce a significant degree of pulmonary edema following intravenous injection of high doses of contrast media in rats. This edema has been shown to be dependent on dose and rate of injection. Metrizamide administered at the same dose causes much less and more transient pulmonary edema than diatrizoate. Although blood osmolalities were significantly and consistently lower following administration of metrizamide compared with diatrizoate, this difference alone does not account for the difference in the degree of pulmonary edema induced by these media.

Complement activation and generation of C3a anaphylatoxin by radiological contrast agents

Using a new radioimmunoassay for the complement-derived anaphylatoxin C3a, both conventional and new low-osmolality contrast agents have been shown to be capable in vitro of activating complement with C3 conversion. The implications of this for some adverse reactions to contrast agents are briefly discussed.

The radiographic detection of acute pulmonary oedema. A comparison of radiographic appearances, densitometry and lung water in dogs

We have induced acute pulmonary oedema in upright anaesthetized dogs by increasing pulmonary microvascular permeability or by extracellular fluid volume overload in order to determine the sensitivity and specificity of the radiograph to the presence of abnormal lung water. Radiographs were taken before and after development of oedema. At the end of the experiment we removed the inflated lungs and froze them in liquid nitrogen and subsequently examined them macroscopically in the frozen state. The extravascular water/dry lung weight ratio was measured gravimetrically on seven portions of each lung. Finally without the base-line films for comparison. We directly measured the change in opacity of the films with a radiographic densitometer. When a dog's mean extravascular water/g dry lung was increased by more than 35% it was invariably recognized, in one or more zones, as definite oedema. Control dogs were reliably recognized as normal when base-line films were used but the distinction between normal and minor degrees of oedema could not be made without the base-line films. There was a positive correlation between radiological grade and lung water, but a great deal of overlap between grades. Densitometry was not a sensitive or reliable method for diagnosing or quantifying oedema. Oedema was usually associated with a decrease in volume of the lower lung zones.