Identify and Manage Patients

Evaluate Patients with CKD

• Early kidney disease usually does not have signs (a change in your body) or symptoms (a change in how you feel). Testing is the only way to know how your kidneys are doing. It is important for you to get checked for kidney disease if you have the key risk factors – diabetes, high blood pressure, heart disease, or a family history of kidney failure.
• A healthcare provider may use several tests to diagnose chronic kidney disease and determine if there is a treatable underlying cause. These include the following:
• Blood test- one way to measure how well your kidneys are working is to figure out your glomerular filtration rate (GFR). The GFR is usually calculated using results from your blood creatinine test. Then the stage of kidney disease is figured out using the GFR. There are five stages of kidney disease, from kidney damage with normal GFR to kidney failure.

Stage	Description	GFR* mL/min/1.73m2
1	Slight kidney damage with normal or increased filtration	More than 90
2	Mild decrease in kidney function	60-89
3	Moderate decrease in kidney function	30-59
4	Severe decrease in kidney function	15-29
5	Kidney failure	Less than 15 (or dialysis)

• 2.Urine tests

    The presence of albumin or protein in the urine (called albuminuria or proteinuria) is a marker of kidney disease. Even small amounts of albumin in the urine, called microalbuminuria, may be an early sign of chronic kidney disease in some people, particularly those with diabetes and high blood pressure.

• 3.Imaging studies

   Imaging tests (such as CT or ultrasound) may be recommended to determine if there are any obstructions (blockages) of the urinary tract, kidney stones, or other abnormalities.

• 4.Kidney biopsy

   In a kidney biopsy, a small piece of kidney tissue is removed and examined under a microscope. The biopsy helps to identify abnormalities in kidney tissue that may be the cause of kidney diseases.
• It is also important to have your blood pressure checked. High blood pressure can be a sign of kidney disease. Keep your blood pressure at or below your target to help protect your kidneys.
• The sooner you know you have kidney disease, the sooner you can get treatment to help delay or prevent kidney failure. If you have diabetes, get checked every year. If you have other risk factors, such as high blood pressure, heart disease, or a family history of kidney failure, talk to your provider about how often you should be tested.
  
  

Identify Patients with CKD

Screen people at risk for CKD, including those with

• diabetes mellitus type 1 or type 2.
• hypertension.
• cardiovascular disease (CVD).
• family history of kidney failure.
  
  

The benefit of CKD screening in the general population is unclear.
The two key markers for CKD are urine albumin and estimated glomerular filtration rate (eGFR). To screen for CKD:

• assess urine albumin excretion to diagnose and monitor kidney damage.  Screen using a spot urine albumin-to-creatinine ratio.
• calculate eGFR from stable serum creatinine levels to assess kidney function. Use the Modification of Diet in Renal Disease (MDRD) Study Equation.
• CKD is generally diagnosed when there is evidence, for more than 3 months, of
• kidney damage (usually urine albumin > 30 mg/g creatinine, but includes other clinical findings such as hematuria, congenital malformations, etc.) and/or
• decreased kidney function (eGFR < 60 mL/min/1.73 m2).
  
  

Staging

Staging systems for chronic disease should identify risk for progression and complications. The current staging system for CKD, based exclusively on eGFR, does not appear to reliably identify those people at greatest risk for progression. Emerging research suggests an approach that includes multiple factors, such as urine albumin, age, and diabetes status may better predict progression.
In addition, the current staging requires accuracy of eGFR above 60 mL/min/1.73 m2. However, values above 60 calculated using the MDRD Study equation are not accurate..
Although kidney function tends to decrease with age, this process has not been well investigated. Many people with age-related kidney function decline may not progress to kidney failure. Thus, the prognosis for a 75-year-old patient with an eGFR of 55 may be different than that for a 45-year-old patient with the same eGFR.
In addition, GFR may be too narrow a basis on which to assess risk for progression.

Establish Cause of CKD

Because kidney damage is generally irreversible, it is important to identify the etiology as early as possible. Specific treatments are available in many cases (e.g., membraneous nephropathy, lupus nephropathy) and a diagnosis will guide management.
Although diabetes is the most common cause of CKD, it is important not to assume that a patient with diabetes and CKD has diabetic kidney disease. However, non-diabetic kidney disease is unlikely in a person with diabetes of long duration with other diabetic complications, physical findings of end-organ diabetic damage, and negative screening laboratory studies.

Suggested initial evaluation:

• complete urinalysis (U/A)
• urine albumin-to-creatinine ratio (UACR)
• creatinine with estimated GFR, blood urea nitrogen (BUN), electrolytes, glucose, calcium, phosphorus, albumin
• complete blood count (CBC)
  
  

For further evaluation, the following tests are often ordered, depending on clinical presentation:

• hepatitis B serology
• hepatitis C serology
• antinuclear antibody test (ANA)
• rheumatoid factor (RF)
• complement 3 (C3)
• complement 4 (C4)
• serum protein electrophoresis (SPEP) and urine protein electrophoresis (UPEP) (in patients over the age of 40)
• renal ultrasound to measure kidney size and to check for echogenicity and hydronephrosis
• dilated retinal exam

If a patient with diabetes has retinopathy, albuminuria, and negative screening tests listed above, it is reasonable to assume the diagnosis is diabetic kidney disease. Patients who do not conform to these criteria should be discussed with a nephrologist.