Renal blood flow (RPF)

Renal blood flow (RPF) measurements were made using a clearance test. A substance is filtered from the glomerulus and discharged from the renal tubules, and is not reabsorbed. After it passes through the kidney tissue once, it can be completely removed. The clearance rate of the substance represents the unit time. The amount of plasma flowing through the kidneys. The commonly used method is intravenous injection of aminoacetic acid, blood samples are taken regularly, urine samples are collected, time is recorded, urine volume per minute is calculated, and aminouric acid concentration and hematocrit in plasma and urine are measured, and then the kidney is calculated by the formula. Blood flow. This method is more cumbersome, and is now clinically used radioactive isotope tracing technique, 131 iodine-o-iodine sodium urate pre-cardiac body surface assay. The normal renal plasma flow rate is from 500 ml to 700 ml/min·1.73 square body surface area. 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: 1, chronic renal insufficiency or chronic pyelonephritis, due to renal vascular damage caused by RPF decreased. 2. In the early stage of hypertension, the effective vascular bed is reduced due to vasospasm and renal arteriosclerosis. 3, shock, heart failure, RPF can be significantly reduced transient. Normal value: Renal blood flow: 600-800ml/min Above normal: 1, early acute glomerulonephritis, due to congestion, renal blood flow can be normal or elevated. 2, metabolic diseases such as acromegaly, giant disease RPF can be elevated. 3. RPF in pregnant women can also be elevated. negative: Positive: Tips: Actively cooperate with the doctor during the examination. Normal value 600-800ml/min. Clinical significance 1, RPF reduction, can be seen in (1) Chronic renal insufficiency or chronic pyelonephritis, the RPF is reduced due to renal vascular damage. (2) In the early stage of hypertension, the effective vascular bed is reduced due to vasospasm and renal arteriosclerosis. (3) When shock and cardiac dysfunction, RPF can be significantly reduced transiently. 2, RPF rises, can be seen in (1) In the early stage of acute glomerulonephritis, renal blood flow may be normal or elevated due to congestion. (2) Metabolic diseases such as acromegaly and giant disease RPF can be elevated. (3) RPF in pregnant women can also be elevated. Low results may be diseases: chronic renal insufficiency, high results of cardiogenic shock may be diseases: acute glomerulonephritis precautions Contraindications: 1. After urography or arteriography. 2, after the application of diuretics, laxatives, antihypertensive drugs. 3. When the body is dehydrated or edema. 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. 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 renal blood flow. Not suitable for the crowd It is not advisable for pregnant and lactating women to perform this test. Adverse reactions and risks A small number of people may have transient facial flushing, sore back, chest tightness, palpitations and other reactions.