Diagnostic Assessments (Kidney Biopsy)

Question 1

Patient Preparation

Answer 1

1. Explain that kidney biopsy can help determine a cause of unexplained kidney problems and direct or change therapy
2. Performed percutaneously (through skin and other tissue) using ultrasound or CT guidance
3. Patient signs an informed consent
4. Patients are NPO for 4-6 hours before procedure
5. Because of the risk of bleeding after the biopsy, coagulation studies such as platelets, aPTT, PT and bleeding times are performed before surgery
6. Hypertension is aggressively managed before and after the procedure because high BP can make stopping bleeding after the biopsy more difficult
7. Uremia also increases risk for bleeding, and dialysis may be prescribed before a biopsy
8. A blood transfusion may be needed to correct anemia before biopsy

Question 2

Procedure

Answer 2

1. Nephrologist obtains tissue samples without an incision
2. Patients receive sedation and are monitored throughout the procedure
3. Placed in prone position
4. Needle depth and placement are confirmed by ultrasound or CT
5. While the patient holds their breath, the needle is advanced into the renal cortex
6. Samples are taken with a spring-loaded coring biopsy needle and sent for pathologic study

Question 3

Follow-up Care

Answer 3

1. The major risk is bleeding into the kidney or tissues external from the kidney at the biopsy site
2. For 24 hours after the biopsy, monitor the (1) dressing site, (2) vital signs (fluctuations in BP), (3) urine output, (4) hemoglobin level and hematocrit
3. Internal bleeding is suspected with (1) flank pain, (2) decreasing blood pressure (3) decreasing urine output, (4) or other signs of hypovolemia
4. Strict bedrest, lying in supine position with a back roll or additional support for 2 to 6 hours
5. Head of bed may be elevated and the patient may resume oral intake of foods and fluids
6. Monitor for hematuria, the most common complication of kidney biopsy
7. If bleeding occurs, IV fluids and PRBC are needed to prevent shock
8. A small amount of bleeding creates enough pressure to compress bleeding sites. This is called tamponade effect
9. If no bleeding occurs, patients can resume general activities after 24 hours. Instruct the patient to avoid lifting heavy objects, exercising or performing other strenuous activities for 1 to 2 weeks after the biopsy. Driving may also be restricted