Renal excretion of endoscopic retrograde cholangiopancreatography injected contrast. A common phenomenon.

The renal excretion of contrast injected during endoscopic retrograde cholangiopancreatography (ERCP) has been described as an uncommon event. Patients with this phenomenon have been considered at increased risk of acute pancreatitis, but idiosyncratic reactions from this intravascular contrast have been discounted as nonexistent. Thirteen patients underwent noncontrast abdominal computed tomography (CT) before ERCP and noncontrast CT plus abdominal radiography immediately after ERCP. Renal excretion of ERCP-injected contrast was seen in two patients on abdominal films and in nine patients by CT. All patients had normal renal function and none developed clinical pancreatitis. Renal excretion of ERCP-injected contrast is much more common than previously suspected. Iodine allergy and possible reaction should be considered when performing this procedure.

Pharmacokinetics of lopamidol after intrathecal administration in humans.

The kinetics of iopamidol, a new nonionic radiocontrast agent, were evaluated in 10 patients undergoing lumbar myelography. The doses of iopamidol administered intrathecally were 11 and 15 ml of a 200-mg iodine per ml solution in one and nine patients, respectively. Radiographs were made within 30 to 40 min and CTs were taken at about 1, 6, and 23 hr after iopamidol administration. The diagnostic quality and usefulness of the conventional and CT myelograms were considered excellent. In the lumbosacral subarachnoid space, the densitometry CT readings were maximal at 1 hr, whereas in the cervical subarachnoid space, peak CT values were reached at 6 hr. Plasma and urine samples were taken at frequent intervals up to 48 hr after the contrast agent was administered. Peak plasma levels of iopamidol were observed at 2.9 hr and were no longer detectable at 48 hr. The 48-hr urinary recovery for all patients averaged 66 +/- 8% of the dose. In all but one patient, iopamidol was cleared almost completely from the CSF within 24 hr. Side effects after iopamidol administration were transient and minor, and were not related to the CT readings or its systemic clearance.

Excretion of aqueous myelographic contrast media in animals undergoing a repeat myelogram.

The rate of elimination of contrast media may be a factor in side effects and complications of aqueous myelography. The authors studied the effect of a previous myelogram and arachnoiditis on the elimination of aqueous contrast media from the subarachnoid space. Serum and cisternal CSF iodine concentrations were measured after experimental myelography in subhuman primates. The transfer of the aqueous contrast media from CSF to serum was slowed and the circulation with the cerebrospinal fluid into the intracranial cisterns was increased by a previous myelogram or arachnoiditis.

Assessment of a non-ionic contrast medium (Amipaque) in the gastrointestinal tract.

Gastrografin and Amipaque with identical iodine content and flavoring were orally administered in 100 ml doses to 10 healthy volunteers in a double-blind crossover study. The nonionic Amipaque has only about one third of the osmolality of Gastrografin, and draws less fluid into the bowel lumen. Consequently there is less dilution with Amipaque, and a higher contrast density in the ileocecal region can be observed. Unlike the highly hypertonic Gastrografin, Amipaque causes less changes in hematocrit, and has only a very mild cathartic effect. No more than 0.4% of the iodine in Amipaque was excreted in the urine during one day, and no more than 0.8% during three days. This was less than the excretion found after ingestion of Gastrografin. Non-ionic media are recommended when there is an indication for use of water-soluble contrast media in the gastrointestinal tract.

Iotroxamide studies in man--plasma binding, renal and biliary excretion studies in jaundiced and anicteric patients.

1.A decrease in the plasma binding of iotroxamide was found in jaundiced people. 2. The decrease in binding was associated with an enhancement in renal excretion. 3. Iotroxamide consistently gave higher biliary iodine concentrations than ioglycamide.

[The effect of oral anti-diabetic agents (suphonyle ureas) on the excretion of intravenous biliary contrast media (author's transl)]. / Der Einfluss oraler Antidiabetika (Sulfonylharnstoffe) auf die Ausscheidung intravenöser Gallenkontrastmittel

Sulphonyle ureas used in the oral treatment of diabetes occupy albumen-binding capacity. Hepatotropic contrast media therefore have difficulty with protein binding and renal excretion is increased. The proportion excreted through the kidneys has been determined in 50 diabetic patients on oral treatment. Demonstration of contrast in the urine was done radiologically, qualitative measurements by a subtraction method. As a control, the same group of patients were examined, having been taken off suphonyle ureas, as well as a group of 50 diabetic patients treated with insulin. While under medication, heteroptropic excretion rose on average to 55% and in some cases to 80%. This results in definite reduction of contrast filling of the biliary tree, occasionally to the extent of preventing a diagnosis. Displacement of sulphonyle urea by contrast was not observed.

Continuous infusion urography in unilateral hydronephrosis.

In cases of unilateral hydronephrosis the urine concentration of contrast medium, for example diatrizoate, depends on the remaining renal function, the rate of turnover in the obstructed renal pelvis and the function of the contralateral kidney. Contrast medium for a single injection or a short infusion time is rapidly excreted by the normal contraleteral kidney, without allowing high enough plasma levels long enough for sufficient urine concentrations in the hydronephrotic kidney. This excretion rate can be compensated for by continuous infusion urography for several hours with large doses of contrast medium (up to 1,250 ml. 30 per cent diatrizoate). This method was theoretically computerized, tested in animals experiments and clinically used in 11 patients. It can improve the diagnostic possibilites of excretory urography, especially in cases of unilateral obstruction, and can minimize the need for retrograde pyelography with its known complications.