antegrade pyelography


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Related to antegrade pyelography: retrograde pyelography

an·te·grade py·e·log·ra·phy

antegrade urography in which the contrast medium is injected into the renal calyces or pelvis.

Intravenous Pyelography

Synonym/acronym: Antegrade pyelography, excretory urography (EUG), intravenous urography (IVU, IUG), IVP.

Common use

To assess urinary tract dysfunction or evaluate progression of renal disease such as stones, bleeding, and congenital anomalies.

Area of application

Kidneys, ureters, bladder, and renal pelvis.

Contrast

IV radiopaque iodine-based contrast medium.

Description

Intravenous pyelography (IVP) is most commonly performed to determine urinary tract dysfunction or renal disease. IVP uses IV radiopaque contrast medium to visualize the kidneys, ureters, bladder, and renal pelvis. The contrast medium concentrates in the blood and is filtered out by the glomeruli passing out through the renal tubules and concentrated in the urine. Renal function is reflected by the length of time it takes the contrast medium to appear and to be excreted by each kidney. A series of images is performed during a 30-min period to view passage of the contrast through the kidneys and ureters into the bladder. Tomography may be employed during the IVP to permit the examination of an individual layer or plane of the organ that may be obscured by surrounding overlying structures. Many facilities have replaced the IVP with computed tomography (CT) studies. CT provides better detail of the anatomical structures in the urinary system and therefore greater sensitivity in identification of renal pathology.

This procedure is contraindicated for

  • high alert Patients who are pregnant or suspected of being pregnant, unless the potential benefits of a procedure using radiation far outweigh the risk of radiation exposure to the fetus and mother.
  • high alert Patients with conditions associated with adverse reactions to contrast medium (e.g., asthma, food allergies, or allergy to contrast medium). Although patients are still asked specifically if they have a known allergy to iodine or shellfish, it has been well established that the reaction is not to iodine, in fact an actual iodine allergy would be very problematic because iodine is required for the production of thyroid hormones. In the case of shellfish the reaction is to a muscle protein called tropomyosin; in the case of iodinated contrast medium the reaction is to the noniodinated part of the contrast molecule. Patients with a known hypersensitivity to the medium may benefit from premedication with corticosteroids and diphenhydramine; the use of nonionic contrast or an alternative noncontrast imaging study, if available, may be considered for patients who have severe asthma or who have experienced moderate to severe reactions to ionic contrast medium.
  • high alert Patients with conditions associated with preexisting renal insufficiency (e.g., renal failure, single kidney transplant, nephrectomy, diabetes, multiple myeloma, treatment with aminoglycosides and NSAIDs) because iodinated contrast is nephrotoxic
  • high alert Elderly and compromised patients who are chronically dehydrated before the test, because of their risk of contrast-induced renal failure.
  • high alert Patients with bleeding disorders or receiving anticoagulant therapy because the puncture site may not stop bleeding.

Indications

  • Aid in the diagnosis of renovascular hypertension
  • Evaluate the cause of blood in the urine
  • Evaluate the effects of urinary system trauma
  • Evaluate function of the kidneys, ureters, and bladder
  • Evaluate known or suspected ureteral obstruction
  • Evaluate the presence of renal, ureter, or bladder calculi
  • Evaluate space-occupying lesions or congenital anomalies of the urinary system

Potential diagnosis

Normal findings

  • Normal size and shape of kidneys, ureters, and bladder
  • Normal bladder and absence of masses or renal calculi, with prompt visualization of contrast medium through the urinary system

Abnormal findings related to

  • Absence of a kidney (congenital malformation)
  • Benign and malignant kidney tumors
  • Bladder tumors
  • Congenital renal or urinary tract abnormalities
  • Glomerulonephritis
  • Hydronephrosis
  • Prostatic enlargement
  • Pyelonephritis
  • Renal cysts
  • Renal hematomas
  • Renal or ureteral calculi
  • Soft tissue masses
  • Tumors of the collecting system

Critical findings

    N/A

Interfering factors

  • Factors that may impair clear imaging

    • Gas or feces in the gastrointestinal (GI) tract resulting from inadequate cleansing or failure to restrict food intake before the study.
    • Retained barium from a previous radiological procedure.
    • Metallic objects (e.g., jewelry, body rings) within the examination field, which may inhibit organ visualization and cause unclear images.
    • Inability of the patient to cooperate or remain still during the procedure because of age, significant pain, or mental status.
  • Other considerations

    • The procedure may be terminated if chest pain or severe cardiac arrhythmias occur.
    • Failure to follow dietary restrictions and other pretesting preparations may cause the procedure to be canceled or repeated.
    • Consultation with a health-care provider (HCP) should occur before the procedure for radiation safety concerns regarding younger patients or patients who are lactating. Pediatric & Geriatric Imaging Children and geriatric patients are at risk for receiving a higher radiation dose than necessary if settings are not adjusted for their small size. Pediatric Imaging Information on the Image Gently Campaign can be found at the Alliance for Radiation Safety in Pediatric Imaging (www.pedrad.org/associations/5364/ig/).
    • Risks associated with radiation overexposure can result from frequent x-ray procedures. Personnel in the room with the patient should wear a protective lead apron, stand behind a shield, or leave the area while the examination is being done. Personnel working in the examination area should wear badges to record their level of radiation exposure.

Nursing Implications and Procedure

Pretest

  • Positively identify the patient using at least two unique identifiers before providing care, treatment, or services.
  • Patient Teaching: Inform the patient this procedure can assist in assessing the kidneys, ureters, and bladder.
  • Obtain a history of the patient’s complaints or clinical symptoms, including a list of known allergens, especially allergies or sensitivities to latex, anesthetics, contrast medium, or sedatives.
  • Obtain a history of the patient’s genitourinary system, symptoms, and results of previously performed laboratory tests and diagnostic and surgical procedures. Ensure that the results of blood tests, especially BUN and creatinine, are obtained and recorded before the procedure.
  • Note any recent barium or other radiological contrast procedures. Ensure that barium studies were performed more than 4 days before the IVP.
  • Record the date of the last menstrual period and determine the possibility of pregnancy in perimenopausal women.
  • Obtain a list of the patient’s current medications including anticoagulants, aspirin and other salicylates, herbs, nutritional supplements, and nutraceuticals (see Effects of Natural Products on Laboratory Values online at DavisPlus). Note the last time and dose of medication taken.
  • Note that if iodinated contrast medium is scheduled to be used in patients receiving metformin (Glucophage) for non-insulin-dependent (type 2) diabetes, the drug should be discontinued on the day of the test and continue to be withheld for 48 hr after the test. Iodinated contrast can temporarily impair kidney function, and failure to withhold metformin may indirectly result in drug-induced lactic acidosis, a dangerous and sometimes fatal side effect of metformin related to renal impairment that does not support sufficient excretion of metformin.
  • Review the procedure with the patient. Address concerns about pain related to the procedure and explain that some pain may be experienced during the test, and there may be moments of discomfort. Inform the patient that the procedure is performed in a radiology department by an HCP and takes approximately 30 to 60 min.
  • Sensitivity to social and cultural issues, as well as concern for modesty, is important in providing psychological support before, during, and after the procedure.
  • Instruct the patient to take a laxative or a cathartic, as ordered, on the evening before the examination.
  • Instruct the patient to remove jewelry and other metallic objects from the area to be examined.
  • Instruct the patient to fast and restrict fluids for 8 hr prior to the procedure. Protocols may vary among facilities.
  • Make sure a written and informed consent has been signed prior to the procedure and before administering any medications.

Intratest

  • Potential complications:
  • Allergic reaction to contrast media is a potential complication.

  • Ensure the patient has removed all external metallic objects from the area to be examined prior to the procedure.
  • Observe standard precautions, and follow the general guidelines in Patient Preparation and Specimen Collection. Positively identify the patient.
  • Ensure the patient has complied with dietary, fluid, and medication restrictions for 8 hr prior to the procedure.
  • Assess for completion of bowel preparation according to the institution’s procedure. Administer enemas or suppositories on the morning of the test, as ordered.
  • Administer ordered prophylactic steroids or antihistamines before the procedure if the patient has a history of allergic reactions to any substance or drug. Use nonionic contrast medium for the procedure.
  • Avoid the use of equipment containing latex if the patient has a history of allergic reaction to latex.
  • Have emergency equipment readily available.
  • Instruct the patient to void prior to the procedure and to change into the gown, robe, and foot coverings provided.
  • Instruct the patient to cooperate fully and to follow directions. Instruct the patient to remain still throughout the procedure because movement produces unreliable results.
  • Place the patient in the supine position on an examination table.
  • A kidney, ureter, and bladder (KUB) or plain film is taken to ensure that no barium or stool obscures visualization of the urinary system.
  • Insert an IV line, if one is not already in place, and inject the contrast medium.
  • Instruct the patient to take slow, deep breaths if nausea occurs during the procedure.
  • Monitor the patient for complications related to the procedure (e.g., allergic reaction, anaphylaxis, bronchospasm).
  • Images are taken at 1, 5, 10, 15, 20, and 30 min following injection of the contrast medium into the urinary system. Instruct the patient to exhale deeply and to hold his or her breath while each image is taken.
  • Remove the needle or catheter and apply a pressure dressing over the puncture site.
  • Instruct the patient to void if a postvoiding exposure is required to visualize the empty bladder.

Post-Test

  • Inform the patient that a report of the results will be made available to the requesting HCP, who will discuss the results with the patient.
  • Instruct the patient to resume usual diet, fluids, medications, and activity, as directed by the HCP. Renal function should be assessed before metformin is resumed if contrast was used.
  • Observe for delayed reaction to iodinated contrast medium, including rash, urticaria, tachycardia, hyperpnea, hypertension, palpitations, nausea, or vomiting.
  • Observe/assess the needle/catheter insertion site for bleeding, inflammation, or hematoma formation.
  • Instruct the patient in the care and assessment of the injection site.
  • Instruct the patient to apply cold compresses to the puncture site as needed, to reduce discomfort or edema.
  • Monitor urinary output after the procedure. Decreased urine output may indicate impending renal failure.
  • Recognize anxiety related to test results, and offer support. Discuss the implications of abnormal test results on the patient’s lifestyle. Provide teaching and information regarding the clinical implications of the test results, as appropriate.
  • Reinforce information given by the patient’s HCP regarding further testing, treatment, or referral to another HCP. Answer any questions or address any concerns voiced by the patient or family.
  • Depending on the results of this procedure, additional testing may be needed to evaluate or monitor progression of the disease process and determine the need for a change in therapy. Evaluate test results in relation to the patient’s symptoms and other tests performed.

Related Monographs

  • Related tests include biopsy bladder, biopsy kidney, biopsy prostate, BUN, CT abdomen, CT pelvis, creatinine, cystometry, cystoscopy, gallium scan, KUB, MRI abdomen, renogram, retrograde ureteropyelography, US abdomen, US bladder, US kidney, US prostate, urine markers of bladder cancer, urinalysis, urine cytology, and voiding cystourethrography.
  • Refer to the Genitourinary System table at the end of the book for related tests by body system.