肾小球滤过率

定义

肾小球滤过率 (GFR) is a test used to check how well the kidneys are working. Specifically, it estimates how much blood passes through the glomeruli each minute. Glomeruli are the tiny filters in the kidneys that filter waste from the blood.

选择的名字

GFR; Estimated GFR; eGFR

如何执行测试

A 血液样本 是必要的.

的 血液样本 is sent to a lab. 的re, the creatinine level in the 血液样本 is tested. Creatinine is a chemical waste product of creatine. Creatine is a chemical the body makes to supply energy, mainly to muscles.

的 lab specialist combines your blood creatinine level with several other factors to estimate your GFR. Different formulas are used for adults and children. 的 formula includes some or all of the following:

• 年龄
• Blood creatinine measurement
• 种族
• 性
• 高度
• 重量

的 肌酐清除率试验, which involves a 24-hour urine collection, can also provide an estimate of kidney function.

如何准备考试

Your health care provider may ask you to temporarily stop any medicines that may affect the test results. 的se include antibiotics and stomach acid medicines.

Be sure to tell your provider about all the medicines you take. Do not stop taking any medicine before talking to your doctor.

Tell your doctor if you are pregnant or think you might be. GFR is affected by pregnancy.

考试的感觉如何

When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there might be some throbbing or a slight bruise. 这很快就会消失.

为什么要进行测试

的 GFR test measures how well your kidneys are filtering the blood. Your doctor may order this test if there are signs that your kidneys are not working well. It may also be done to see how far kidney disease has progressed.

的 GFR test is recommended for people with chronic kidney disease. It is also recommended for people who may develop kidney disease due to:

• 糖尿病
• Family history of kidney disease
• Frequent urinary tract infections
• 心脏病
• 高血压
• 尿路阻塞

正常的结果

According to the National Kidney Foundation, normal results range from 90 to 120 mL/min/1.73 m². Older people will have lower than normal GFR levels because GFR decreases with age.

Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your doctor about the meaning of your specific test results.

异常结果意味着什么

低于60ml /min/1.73 m2 for 3 or more months are a sign of chronic kidney disease. A GFR lower than 15 mL/min/1.73 m2 is a sign of kidney failure and requires immediate medical attention.

Lower than normal creatinine clearance may indicate:

• Kidney problems, such as damage to the tubule cells
• 肾功能衰竭
• Too little blood flow to the kidneys
• Damage to the filtering units of the kidneys
• Loss of body fluids (dehydration)
• 膀胱出口梗阻
• 心脏衰竭

风险

的re is little risk involved with having your blood taken. Veins and arteries vary in size from one person to another and from one side of the body to the other. Taking blood from some people may be more difficult than from others.

Other risks associated with having blood drawn are slight, but can include:

• 大出血
• Fainting or feeling lightheaded
• Multiple punctures to locate veins
• Hematoma (blood accumulating under the skin)
• Infection (a slight risk any time the skin is broken)

参考文献

Krishnan A, Levin A. Laboratory assessment of kidney disease: glomerular filtration rate, urinalysis, and proteinuria. In: Yu ASL, Chertow GM, Luyckx VA, Marsden PA, Skorecki K, Taal MW, eds. Brenner and Rector's 的 Kidney. 11日艾德. Philadelphia, PA: Elsevier; 2020:chap 23.

Landry DW, Bazari H. Approach to the patient with renal disease. In: Goldman L, Schafer AI, eds. Goldman-Cecil医学. 26日艾德. Philadelphia, PA: Elsevier; 2020:chap 106.