Specific Considerations Prior to Performance of Renal Biopsy

In counseling an individual patient with one of the above indications for biopsy, the clinician must weigh the likelihood of obtaining information that will change treatment against the risk of the procedure itself. Factors to consider are the presence or absence of coagu-lopathy, increased renal echogenicity, chronic renal dysfunction, uncontrolled hypertension, a solitary kidney, the inability to comply with verbal instruction, hydronephrosis, active pyelonephritis, or a mass that may be neoplastic. Each of these conditions increases the risk of percutaneous biopsy. The presence of small and echodense kidneys by ultrasound and/or chronic renal dysfunction substantially diminish the diagnostic value of the procedure.

Before percutaneous renal biopsy, patients need to understand that the procedure is a diagnostic study and not a treatment. A platelet count and prothrombin (PT) and partial prothrombin times (PPT) should be obtained. Antiplatelet drugs such as aspirin or other nonsteroidal anti-inflammatory drugs should be omitted for a period of at least one week if the biopsy is elective. Systemic anticoagulants should also be stopped before the procedure. Patients receiving heparin should have the drug discontinued at least 6 hours and preferably 12 hours before the procedure. A PPT should be in the normal range before the biopsy. Warfarin should be stopped long enough for the PT to normalize. In certain high-risk patients who must minimize the period off warfarin, it may be prudent to administer heparin as a short-acting agent after warfarin is stopped and reinstate heparin and warfarin 12-24 hours after the biopsy, continuing the heparin until the PT is in a therapeutic range. The use of a bleeding time as a pre-biopsy screening study is common but not universally accepted. There are no data indicating that use of this test decreases the risk of hemorrhagic complication after biopsy. Nonetheless, many clinicians continue to use this study. It is probably most relevant in patients with renal dysfunction who may have associated secondary platelet dysfunction. Ar-ginine desmopressin (DDAVP) can be useful in normalizing a prolonged bleeding time in such patients. The clinician should also determine if the patient has 2 functioning kidneys before percutaneous biopsy. An IVP or radionuclide study were previously used for this purpose. A reasonable alternative is an ultrasound evaluation demonstrating 2 kidneys of similar size, and if available, a concomitant Doppler study demonstrating normal perfusion to each kidney.

Blood Pressure Health

Blood Pressure Health

Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...

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