27.10: Imaging Studies VII: Vascular Imaging

Definition

Renal angiography, also known as renal arteriography, is an imaging technique used to obtain a comprehensive view of blood flow and the vascular structure of blood vessels in the kidneys and surrounding areas.

Purpose

Renal angiography detects blood vessel abnormalities in the kidneys, such as aneurysms, stenosis, thrombosis, vascular tumors, and renal artery stenosis. It evaluates kidney function and guides interventional treatments like angioplasty or stent placement.

Pre-Procedure Care

Patient Preparation

1. Informed Consent: Obtain written informed consent, ensuring the patient understands the procedure, risks, and benefits.
2. Medical History: Review the patient’s history, including kidney disease, allergies (especially to iodine or contrast dye), bleeding disorders, and current medications (such as anticoagulants).
3. Fasting: Ask the patient to fast for 6-8 hours before the procedure to reduce potential complications from sedation or the contrast dye.
4. Laboratory Tests: To assess the patient's readiness, conduct renal function tests, such as serum creatinine or eGFR, a coagulation profile, and a complete blood count (CBC).
5. IV Access: Establish an IV line for administering the contrast dye and any necessary medications.
6. Vital Signs: Record baseline vital signs, particularly blood pressure, as this is crucial for monitoring kidney perfusion throughout the procedure.

Patient Education

1. Procedure Overview: Explain each step of the procedure, including the sensations they may feel, such as warmth from the dye, and the importance of staying still during imaging.
2. Hydration: Encourage the need for adequate hydration both prior to and following the procedure in order to facilitate the elimination of contrast dye from the kidneys.

Intra-Procedure Care

Positioning and Sedation

• The nurse positions the patient supine on the imaging table. Administer mild sedation if needed to keep the patient calm and still.

Aseptic Technique

• The physician prepares the femoral or radial artery using aseptic techniques to minimize infection risk.

Catheter Insertion

• The physician inserts a catheter into an artery, usually the femoral artery, and guides it to the renal arteries using fluoroscopy.

Contrast Injection and Imaging

1. The physician injects the contrast dye into the renal arteries, capturing images as it travels through the blood vessels. The patient may feel warmth or flushing from the dye.
2. The nurse continuously monitors vital signs and oxygen levels, particularly in high-risk patients, to ensure safety throughout the procedure.

Post-Procedure Care

Vital Signs Monitoring

Monitor vital signs such as blood pressure, heart rate, and respiratory rate regularly at the insertion site to identify any immediate complications, including bleeding or hematoma.

Observation for Complications

1. Insertion Site: Examine the catheter site for bleeding, swelling, or hematoma signs.
2. Kidney Function: Monitor for signs of contrast-induced nephropathy, such as decreased urine output or elevated serum creatinine levels.

Hydration

• Encourage oral fluids or provide IV fluids to promote kidney filtration and help flush the contrast dye from the system.

Bed Rest

• Instruct the patient to stay on bed rest for a few hours, keeping the accessed leg (if the femoral artery was used) straight to prevent bleeding from the insertion site.