Chapter 90 Intravenous Pyelogram (Excretory Urography)
The intravenous pyelogram (IVP) is also called an excretory urography. This test assists with visualization of the following:
• Presence, size, configuration, and function of the kidneys, the renal pelvis, the ureters, and the bladder
• Renal function (assessed by timing the clearance of the contrast medium through the kidneys)
• Urinary or kidney abnormalities (e.g., tumors, polycystic kidney disease, renovascular hypertension, hydronephrosis, renal calculi, vesicoureteral reflux, or abscess)
• Distortions, strictures, scarring, and distention from obstruction
• Displacement of the kidneys, the ureters, or the bladder may indicate the presence of a mass or other abnormality.
Intravenous (IV) radiopaque contrast material is injected and assessed as it passes through the kidney, the ureters, and the bladder. The dye is filtered by the kidney and passes through renal tubules. Traditionally, visualization is achieved through a sequence of x-ray films taken at set intervals over the 30 to 45 minutes. Computed tomography (CT) and magnetic resonance imaging (MRI) are newer techniques being used for urography imaging.
Congenital abnormalities such as absent or displaced kidneys, horseshoe kidneys, and abnormalities of the ureter are detected by assessing size and position of the structures compared to normal. Retroperitoneal tumors are detected by assessing kidney displacement and/or compression of renal structures. Extrinsic or intrinsic tumors, cysts, stones, or scar tissue can be detected by assessing the flow of dye through the renal pelvis, the ureter, and the bladder. IVP after trauma to the urinary system may reveal urinary leakage outside the urinary system. Renal hematomas are detected by assessing kidney contours. If renal arterial blood flow is interrupted (e.g., renal artery blood clots, artery laceration), the contrast media may not be visualized or the clearance time may be significantly increased. If glomerular disease is present (e.g., glomerulonephritis), a delay in clearance time reflects the decreased glomerular filtration rate.
NURSING ASSESSMENT
1. Obtain a careful history, assessing for contraindications for IVP and conditions that are related to increased risk of complications including:
2. Assess the child’s developmental level and previous experience with medical procedures. Plan and implement preparation as appropriate for the individual child.
NURSING INTERVENTIONS
Preprocedural Care
1. Inform radiology staff and health care provider if allergies, sensitivity to iodine or shellfish, and/or other significant medical problems are present. Premedicate with steroids and diphenhydramine (Benedryl), if ordered, for prophylaxis in cases of suspected sensitivity to the contrast material.
2. Ensure the availability of antihistamines, epinephrine, vasopressors, steroids, oxygen, normal saline, IV fluids, and resuscitation equipment in case they are needed for treating an anaphylactic response to the dye.
3. Administer cathartic, laxative, and/or enema the evening before and the morning of the procedure, as ordered. Infants and young children are generally excluded. Fecal material, barium, and gas in the bowel can impair visualization of renal structures.
4. Maintain food and fluid restrictions. Frequently, solid foods are restricted 8 to 12 hours before the procedure. Clear fluids may or may not be permitted according to institutional policies. High IV infusion rates may have to be decreased before the IVP. Although slight dehydration assists with concentrating the dye, adequate hydration before and after the procedure is needed to prevent complications related to the contrast medium.
5. Assess fluid, electrolyte, and renal status (serum BUN and creatinine levels). Report any lab results that indicate renal failure and/or dehydration, since the dye may worsen renal function.
Postprocedural Care
1. Observe for reactions to the dye. Many patients experience transient warmth, facial flushing, or salty or metallic taste. Mild reactions may include nausea, vomiting, and occasional wheals. Serious reactions are related to anaphylactic allergic reaction to the dye. Promptly notify the physician if any reaction occurs. Be prepared to administer antihistamines if symptoms persist. If anaphylaxis occurs (rare), be prepared to resuscitate using oxygen, positive pressure ventilation, diphenhydramine, steroids, epinephrine, fluid bolus, and vasopressors as indicated.
2. Ensure adequate oral or IV hydration to replenish fluids and to avoid dehydration. Assess for adequacy of urine output. Instruct parents to report any decrease in normal urine output following the procedure, since it may indicate renal impairment.
3. Observe for signs of extravasation at the IV insertion site (elevate extremity, apply warm soaks, and implement other interventions as needed).
4. Instruct family to assess for and report delayed response to the dye and other abnormalities to their health care provider.
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U.S. National Library of Medicine, National Institutes of Health. Intravenous Pyelogram. [(serial online)] .MedlinePlus, 2006. www.nlm.nih.gov/medlineplus/ency/imagepages/9481.htm. Accessed March 10
WebMD:. Intravenous Pyelogram. [(serialonline)] .WebMD, 2006. www.webmd.com/hw/health_guide_atoz/hw231427.asp. Accessed March 10
