Renal function test. What?
Renal function examination is some targeted examinations to understand renal function. Routine items are blood tests, including three items of renal function (creatinine, uric acid and urea nitrogen). If necessary, it can be judged by urine examination or kidney B-ultrasound.
In the early stage of renal injury, most patients may have no symptoms at all, or the symptoms are mild and easy to be ignored. However, with the progress of the disease, symptoms of different degrees can gradually appear, such as fatigue, fatigue, eyelid, face or lower limb edema. Early renal function examination can find problems, so as to avoid irreversible damage to the kidney and even develop into uremia. Therefore, people with the above symptoms or patients with diabetes and hypertension should have regular renal function examinations every year.
Renal function examination time
The time of renal function examination is also particular. Need to draw blood on an empty stomach for renal function examination, it is best to go to the hospital for examination in the morning; It is suggested that pregnant couples go to the hospital for renal function examination 3 months before pregnancy; As for the daily physical examination, you can do a comprehensive physical examination of renal function and liver function every six months to find out the hidden dangers of the body as soon as possible.
Renal function examination items
1, renal function test (venous blood)
Examination contents: including serum creatinine (Scr), glomerular filtration function, endogenous creatinine clearance rate (Ccr) and blood urea nitrogen (BUN).
Preparation for examination: Eat normally for three days before examination, but the daily intake of protein should be less than 40g to avoid strenuous exercise. Fasting after dinner the day before the exam until the morning of the exam, that is, after the night before blood drawing 19: 00, you cannot eat or drink.
Examination method: Take 2-3 ml of venous blood on an empty stomach and send it for inspection immediately.
2, urine routine (urine test)
Examination contents: including urine volume (vol), urine color (col), urine specific gravity (SG), urine sugar (U-Glu), urine protein (R-PRO) and other items.
Preparation for examination: It is recommended to get up in the morning and send urine for the first time.
Inspection method:
1. Took the sterilized urine cup from the medical staff and went to the bathroom to prepare for urination.
2. After urinating for about 2 seconds, use a sterilized urine cup to catch the rest of the urine, which takes about 2-5 ml.
3. Send the urine to the examination window for medical staff to check. Generally speaking, urine test is done in the laboratory.
Precautions for inspection: it is best to take middle urine when leaving urine. According to the sequence of urination, urine can be divided into anterior segment, middle segment and posterior segment. Because the front urine and the back urine are easy to be polluted.
3. Renal ultrasound
Examination contents: Determine the size, position and shape of the kidney, distinguish whether the tumor in the kidney is cystic or solid, measure the size of the transplanted kidney, and continuously observe the changes of the transplanted kidney.
Preparation for examination: generally, it is not necessary to hold the urine, but drink 30 0-500 ml of water before examining the bladder and prostate, and it is best not to urinate for 2-3 hours to fill the bladder.
Inspection method:
1. The most commonly used position is prone position. Put your hands on your head, try to relax, keep your chest close to the examination table, and relax your waist muscles. When standing examination is needed, the patient should turn his back to the examining doctor, put his hands on his chest, stand upright and not skew.
2. Before the exploration, the doctor will apply a coupling agent similar to facial cleanser on the exploration site, so that the probe can be in close contact with the skin and the ultrasonic wave can smoothly enter the internal organs. This coupling agent is safe, non-toxic and non-irritating to the skin. After the inspection, gently wipe it with soft paper.
Reference value of renal function examination
Reference value of renal function examination:
Note: Determination of glomerular filtration function
The index reflecting glomerular filtration function is glomerular filtration rate (GFR), that is, the amount of plasma filtrate filtered through glomerulus in unit time. Endogenous creatinine clearance rate (Ccr) is the most commonly used index of glomerular filtration function in clinic.
The abnormal risk of blood urea nitrogen (BUN) in the normal range of reference items is 1.70 ~ 8.30 mmol/l, and there is a risk of kidney disease if this value rises, but whether there is kidney disease can not be diagnosed only by the increase of BUN. The serum creatinine (Cr) is 44.00 ~ 88.00 umol/L. When the serum creatinine is significantly higher than the normal value, it indicates that the renal function may have been damaged. When the serum uric acid (UA) rises in the range of 89.00 ~ 357.00 μm ol/ this value suggests that there may be risks such as renal failure and polycythemia. If the creatinine clearance rate (CCR) in blood is 0.80 ~1.20 ml s-1/m2, the risk of glomerular filtration dysfunction will increase. Blood urea 3.2 ~ 7.0 mmol/L may be at risk of acute and chronic nephritis, severe pyelonephritis and other diseases. Urinary creatinine increased by 7 ~ 8 mmol/d: hunger, fever, acute and chronic consumption and other diseases, after strenuous exercise, etc. ? Decrease: renal failure, muscular atrophy, anemia, leukemia, etc. β2- microglobulin clearance test rose from 23 to 62 μ l/min: renal tubular damage. This test is a reliable index to understand the degree of renal tubular damage, especially helpful to find mild patients. The inulin clearance rate increased by 2 ~ 2.3 ml/s (adults aged 20 ~ 29): various conditions of increased cardiac output (such as high fever, hyperthyroidism, pregnancy), high protein diet, early diabetic nephropathy. ?
Decrease: acute and chronic renal failure, acute and chronic glomerulonephritis, nephrotic syndrome, pyelonephritis and other kidney diseases.
Note: With the increase of age, the inulin clearance rate decreased year by year. ?
Normal value of urine routine:
Within the normal range of the reference project, the abnormal risk (pH) is 4.6 ~ 8.0 (average 6.0), which is common in frequent vomiting and respiratory alkalosis.
Reduce urine specific gravity (SG) which is common in acidosis, chronic glomerulonephritis and diabetes. (1.015 ~1.025) is common in high fever, cardiac insufficiency and diabetes.
URO of chronic glomerulonephritis and pyelonephritis is greater than 16, indicating that those who are negative for jaundice occult blood (BLO), positive for protein (+) and positive at the same time should consider kidney disease and negative for hemorrhagic white blood cells (WBC).
Blood urea nitrogen, creatinine and uric acid are mainly excreted with urine after glomerular filtration. When glomerular filtration function decreases, the plasma concentration will increase, and uric acid is helpful for early diagnosis of renal diseases.
1. Pregnancy-induced hypertension syndrome: During normal pregnancy, due to the increase of metabolites of expectant mothers and fetuses, the excretion of blood urea nitrogen and creatinine will also increase, while the recovery of urine salt by renal tubules will decrease, and the plasma urea nitrogen, creatinine and uric acid will all decrease in different degrees. If the three levels rise at the same time, pregnancy-induced hypertension should be considered first.
2. The simultaneous increase of blood urea nitrogen and creatinine is found in chronic nephritis, chronic pyelonephritis and renal arteriosclerosis.
3. Uric acid increased significantly in acute and chronic glomerulonephritis, which appeared earlier than the increase of blood urea nitrogen and creatinine.
Matters needing attention in renal function examination
Renal function test needs fasting, because blood needs to be drawn, eating will affect blood sugar level, leading to inaccurate test results. In addition, after eating, the contents of gastrointestinal tract will increase, and organs including kidneys will be crowded to varying degrees. The edge of the organ is not easy to display, and information will be missed, which will confuse the examination results with the actual situation.
There is no need to arrange a special diet before renal function examination, such as eating vegetarian food, as long as the nutrition is balanced. Eating some foods that tonify the kidney at ordinary times is helpful for kidney health, such as animal meat, eggs, bone marrow, black sesame, cherry, mulberry and yam. These foods have different degrees of kidney-tonifying effects.
How much is the renal function examination?
The cost of renal function examination is determined according to the grade and area of the examination hospital and the actual examination items. The cost of renal function examination ranges from tens of yuan to one or two hundred yuan. It is recommended to consult the specific situation of the local hospital.