DOSAGE AND ADMINISTRATION
RenoCal-76 (Diatrizoate Meglumine and Diatrizoate Sodium Injection USP) should be at body temperature when injected, and may need to be warmed before use. Syringes should be rinsed as soon as possible after injection to prevent freezing of the plunger.
Withdrawal of the contrast agent should be accomplished under aseptic conditions with sterile needle and syringe.
Excretion Urography and Nephrotomography
Appropriate preparation of the patient is desirable for optimal results. A laxative the night before the examination, a low residue diet the day before, and low liquid intake for 12 hours prior to the procedure may be used to clear the gastrointestinal tract and to induce a partial dehydration which is believed to increase the urinary concentration of the contrast medium. Enemas are to be avoided to prevent rehydration.
Preparatory partial dehydration is not recommended in infants, young children, the elderly, those with impaired renal function, or azotemic patients (especially those with polyuria, oliguria, diabetes, advanced vascular disease, or preexisting dehydration, see PRECAUTIONS). The undesirable dehydration in these patients may be accentuated by the osmotic diuretic action of the medium.
In uremic patients partial dehydration is not necessary and maintenance of adequate fluid intake is particularly desirable.
The usual intravenous dose for patients aged 16 years or more is 20 mL, but 30 to 40 mL have been used. Children require less in proportion to weight: Under 6 months of age–4 mL; 6 to 12 months–6 mL; 1 to 2 years–8 mL; 2 to 5 years–10 mL; 5 to 7 years–12 mL; 8 to 10 years–14 mL; 11 to 15 years–16 mL.
The preparation is given by intravenous injection. If flushing or nausea occurs during administration, injection should be slowed or briefly interrupted until the side effects have disappeared.
A scout film should be made before the contrast medium is administered. To allow for individual variation, several films should be exposed beginning approximately five minutes after injection. In patients with renal dysfunction optimal visualization may be delayed until 30 minutes or more after injection.
NOTE: In infants and children and in certain adults, the medium may be injected intramuscularly. The suggested dose is the same as the intravenous dose divided and given bilaterally in the gluteal muscles. Radiographs should be taken at 20, 40, and 60 minutes after the medium is injected.
Nephrotomography may be performed when prior urography has failed to provide diagnostic information. At high dosage, RenoCal-76 may be used to intensify and prolong the nephrographic effect (especially with tomography) when the prime purpose is examination of the renal parenchyma. For example, this method may be employed in the preoperative differentiation of renal masses and damage to the renal parenchyma such as that caused by infarcts or infections.
The suggested dose is 100 mL administered by rapid bolus intravenous injection or intravenous infusion. The usual time interval for administration of the dose has ranged up to four minutes for bolus injections and up to 15 minutes for infusions, depending on the volume of the solution. During the period of intense blush of the renal parenchyma (nephrographic phase), tomographic “cuts” spaced 1 cm apart are obtained through the entire thickness of both kidneys. The complete film series should be exposed within 60 to 90 seconds following administration of the dose for best results. The number of “cuts” (longitudinal) will vary in individual cases.
RenoCal-76 injected into the aorta by the translumbar or retrograde method of administration, permits radiographic visualization of the aorta, its major branches and the abdominal arteries. An incidental nephrogram is obtained as the contrast medium travels through the renal vasculature, provided it has been injected above the renal artery.
Patients should be prepared in a manner similar to that used for intravenous urography. Premedication with a suitable barbiturate is generally indicated.
As in any form of surgery, certain hazards accompany aortographic procedures (see ADVERSE REACTIONS).
For adults and children over 16 years of age, the usual dose is 15 to 40 mL as a single injection, repeated if indicated. Children require less in proportion to weight. Doses up to a total of 160 mL have been given safely.
Since the medium is given by rapid injection in this procedure, patients should be watched for untoward reactions during the injection. Unless general anesthesia is employed, patients should be warned that they may feel some transient pain or burning during the injection followed by a feeling of warmth immediately afterward.
A scout film should be made before the contrast agent is administered. The first radiogram should be taken as the last few mL of the contrast medium are being injected.
Angiocardiography, with RenoCal-76 (Diatrizoate Meglumine and Diatrizoate Sodium Injection USP) may be performed by injection into a large peripheral vein or by direct catheterization of the heart. An excretory urogram can be obtained 10 to 15 minutes after injection of the contrast medium since it is concentrated in and eliminated by the kidneys.
Patients should be prepared in a manner similar to that used for intravenous urography. Appropriate preanesthetic medication should be given.
Clinical studies in man and related animal experiments, have suggested that the hypertonicity of diatrizoate contrast agents produces significant hemodynamic effects, especially in right-sided injections. Large volumes of such agents cause a drop in peripheral arterial and systemic pressures and cardiac output, a rise in pulmonary arterial and right-heart pressures, bradycardia, and regular ectopic beats. Resulting effects on peripheral arterial and pulmonary arterial pressures are postulated to be due to mechanical blockage of the pulmonary vascular bed and clumping of red cells.
Hypertonic solutions cause a decrease in hematocrit in vitro and in vivo, and shrinkage of red blood cells.
It is suggested that hemodynamic changes be monitored and that pressures considered abnormal under roentgenographic conditions be allowed to return to a preangiographic level before continuation of radiopaque injection; this usually takes 15 minutes.
The suggested single dose for children under five years of age is 10 to 20 mL, depending on the size of the child. For children 5 to 10 years of age, single doses of 20 to 30 mL are recommended. Doses up to a total of 100 mL have been given safely.
Since the contrast medium is given by rapid injection, the patient should be watched for untoward reactions during the injection. Some patients not under general anesthesia may experience a feeling of bodily warmth, tightness of the chest, and throbbing headache. All these sensations are of short duration. Transient nausea and vomiting may occur in some patients.
A preliminary control film should be made in the usual manner.
Appropriate preparation of the patient is indicated, including suitable premedication. For visualization of an entire extremity, a single dose of 20 to 40 mL is suggested; for the upper or lower half of the extremity only, 10 to 20 mL is usually sufficient.
Injection is made into the femoral or subclavian artery by the percutaneous or operative method. Because the contrast agent is given by rapid injection, flushing of the skin may occur. Patients not under general anesthesia may experience nausea and vomiting or a transient feeling of warmth. Vascular spasm is not likely to occur.
A scout film should be made routinely before administering the contrast medium. Radiograms of the upper half of the extremity are taken while the last few mL are being injected, followed by radiograms of the lower half of the extremity a few seconds later.
Selective Renal Arteriography
The usual dose is 5 to 10 mL injected into either or both renal arteries via femoral artery catheterization. This dose may be repeated as necessary; doses up to 60 mL have been given.
Selective Visceral Arteriography
The usual dose is 30 to 50 mL injected into the appropriate visceral artery (celiac axis and its branches, superior mesenteric artery, or inferior mesenteric artery) via femoral artery catheterization. This may be repeated as necessary. It is recommended that the combined total dose not exceed 250 mL.
Selective Coronary Arteriography
The usual dose is 4 to 10 mL injected into a coronary artery. This dose, repeated as necessary, may be administered into each coronary artery; doses up to a total of 150 mL have been given. Patients should be monitored continuously by ECG throughout the procedure.
Selective Coronary Arteriography Combined with Left Ventriculography
For left ventriculography the usual dose is 35 to 50 mL injected into the left ventricle. This may be repeated as necessary. It is recommended that the total dose for combined selective coronary arteriography and left ventriculography not exceed 200 mL.
Intravenous Digital Subtraction Angiography (DSA)
Diagnostic-quality arteriograms can be obtained by intravenous administration of RenoCal-76 (Diatrizoate Meglumine and Diatrizoate Sodium Injection USP) and employment of digital subtraction and computer imaging enhancement equipment. This technique has the advantage of being less invasive than the corresponding intra-arterial selective catheter placement technique. The dose is administered into a peripheral vein by mechanical pressure injection, although sometimes by rapid manual injection (see PRECAUTIONS). This technique has been used most frequently to visualize the ventricles, the aorta and most of its larger branches including the carotid, coronary, pulmonary, intracranial, ophthalmic, vertebral, renal, celiac, mesenterics and the major peripheral arteries of the limbs, and for visualization of graft patency.
The usual dose of RenoCal-76 (Diatrizoate Meglumine and Diatrizoate Sodium Injection USP) per bolus injection ranges between 30 and 60 mL (approx. 0.5 to 1 mL/kg) administered intravenously at a rate of 7.5 to 30 mL per second. When indicated, multiple bolus injections of RenoCal-76 (200 mL maximum total volume) may be administered; dosage and rate of injection are generally determined by considerations of age, weight, renal function and arterial site to be studied, as well as by type of equipment and technique to be used. First exposures are made on the basis of calculated circulation time.
The suggested dose is 50 to 125 mL by intravenous administration; scanning may be performed immediately after completion of administration. Doses for children should be proportionately less, depending on age and weight.
No special patient preparation is required for contrast enhancement of CT brain scanning. However, it is advisable to insure that patients are well hydrated prior to examination.