Glomerular Filtration Fraction (GFF)

The amount of filtrate produced by the two kidneys per unit time is called the glomerular filtration rate, which is about 125 ml/min in normal adults. The ratio of glomerular filtration rate to renal plasma flow is called the filtration fraction. The renal plasma flow rate per minute is about 660 ml, so the filtration fraction is 125/660 x 100% ≈ 19%. This result indicates that about one-fifth of the plasma flowing through the kidney is filtered into the sac by the glomerulus to produce primary urine. Glomerular filtration rate and filtration fraction are indicators of renal function. Basic Information Specialist classification: urinary examination classification: urine / kidney function test Applicable gender: whether men and women apply fasting: not fasting Analysis results: Below normal: Often due to glomerular filtration dysfunction, seen in acute or chronic glomerulonephritis. Normal value: Glomerular filtration fraction: 18%-20% Above normal: Often caused by a decrease in RPF, mainly renal dysfunction, seen in hypertension or heart failure. negative: Positive: Tips: Actively cooperate with the doctor during the examination. Normal value GFF = GFR (glomerular filtration rate) / RPF (kidney plasma flow)] 0.18 ~ 0.22. Clinical significance 1. Elevation: The decrease of renal plasma flow causes renal dysfunction, such as hypertension and renal insufficiency. 2, lower: glomerular filtration dysfunction, seen in glomerular lesions, acute and chronic glomerulonephritis. Low results may be diseases: high heart failure results may be diseases: chronic glomerulonephritis, acute glomerulonephritis precautions Need to take blood on an empty stomach to take samples for testing. Eat at least three days before the test, do not drink alcohol, overeating or excessive fatigue, so as not to affect the test results. Blood samples taken only in the morning, generally no blood is drawn in the afternoon (except for emergency), and a test report can be taken in the afternoon. Please consult the patient to arrange the time for examination and treatment, so as not to get the inspection results in time. Inspection process 1. On the morning of the test, rest on an empty stomach, drinking water at 500 ml at 7 o'clock, and indwelling the catheter. 2, 7:30 take urine 10ml, venous blood 2ml (test blank). 3. Immediately inject a sterile 200 g/LPAH solution into the mixture at a dose of 0.4 ml/kg body weight within 10 minutes, and then add 500 ml of physiological saline solution in a solution of 10 ml of a 200 g/LPAH solution for maintenance infusion. 4. At 8:30, clamp the catheter. At 8:50, 4 ml of venous blood was taken, followed by emptying the bladder and measuring the amount of urine. The bladder was rinsed with 20 ml of physiological saline, and 20 ml of air was injected to drain the fluid in the bladder. The rinse solution was combined with urine, mixed, and 10 ml was taken to determine the PAH content. 5, 9:10, the first repeated blood and urine samples; 9:20 second repeated blood and urine samples (same operation 4). 6. Determine the PAH concentration according to the procedure. Mix each time the reagent is added and place for 3 min. The color development was stable (10-15 min) and the blank tube was zeroed at 540 nm, and the absorbance values ​​of the tubes were read. 7. Determine the glomerular filtration fraction. Not suitable for the crowd no. Adverse reactions and risks no.