urine dilution test

The urine dilution test is an examination method to check whether the glomerular acidification function is normal. The principle is that the blood is diluted after drinking water, the plasma osmotic pressure (Posm) is decreased, the secretion of antidiuretic hormone (ADH) is reduced, resulting in an increase in urine volume, an increase in urine volume and a decrease in urine osmotic pressure (Uosm). Inappropriate population: severe renal failure with heart failure, high ascites, severe hypoproteinemia and water retention. Forbidden before examination: Do not eat before checking. Requirements for inspection: 1. The factors affecting the results of this test are basically the same as the concentration test. 2. This test is not the first choice because the water load is unfavorable to the patient. Basic Information Specialist classification: urinary examination classification: urine / kidney function test Applicable gender: whether men and women apply fasting: not fasting Tips: Do not eat before checking. Severe renal failure with heart failure, high ascites, severe hypoproteinemia and water retention are not suitable for this examination. Normal value Normal person Uosm80Uosm/kgH2O, urine specific gravity at least once 1.003, in line with the aforementioned dilution function is normal. Under normal circumstances, the renal tubules have a good urine concentration and dilution function. Clinical significance Abnormal results are normal: human Uosm80Uosm/kgH2O, urine specific gravity at least once 1.003, greater than the above value is test positive, that is, the dilution function is reduced. 1. Dilution function is seen in any cause of distal renal tubules, collecting duct, papillary tube structural damage and dysfunction, such as acute and chronic renal insufficiency, chronic interstitial nephritis, toxic and drug-induced renal tubules, interstitial damage Etc., this test can be positive. 2. Free water clearance rate (CH2O)-25ml/h (absolute value>25), Uosm/Posm>1, suggesting excessive water reabsorption, found in cirrhosis, chronic heart failure, etc., may be due to inappropriate secretion of ADH Therefore. 3. Loss of dilution function, mostly in the late stage of renal failure. People who need to be examined: renal insufficiency for various reasons, and unexplained changes in urine output. Precautions Forbidden before examination: Do not eat before checking. Requirements for inspection: 1. The factors affecting the results of this test are basically the same as the concentration test. 2. This test is not the first choice because the water load is unfavorable to the patient. Inspection process 1. Empty the bladder in the morning, drink 1500ml (20ml/kg body weight) on an empty stomach, drink it in 30min, and stay in bed. 2. Leave the urine once every 30 minutes after drinking water, a total of 4 times - 8 times, until the total urine volume reaches 80% of the drinking water. 3. Determine the specific gravity and Uosm of each urine, and take the lowest value as the test result. Not suitable for the crowd Inappropriate population: severe renal failure with heart failure, high ascites, severe hypoproteinemia and water retention. Adverse reactions and risks No related complications or hazards.