urine concentration test

The urine concentration dilution test is to observe the ability of the distal renal tubule to concentrate urine in the state of water shortage. The function of the urine concentration of the distal tubule can be understood by measuring the specific gravity of the urine. In a normal urine sample of 3 times, the relative density is >1.026 (the elderly is above 1.020); the relative density of urine <1.020 means that the kidney is poorly concentrated. When the renal function is extremely damaged, the highest relative density of urine is 1.010; in uremia, the urine is relatively conspicuously 1.010~1.012; glomerulonephritis, pyelonephritis, hypokalemia and hyperkalemia nephropathy, etc. . Basic Information Specialist classification: urinary examination classification: urine / kidney function test Applicable gender: whether men and women apply fasting: not fasting Tips: Maintain a normal diet and sleep. Severe renal failure, uremia (no water can aggravate the condition) is not suitable for this examination. Normal value At least one of the three specimens has a specific gravity of >1.025. Clinical significance The highest proportion of renal function extreme injury was 1.010; the proportion of uremia was 1.010~1.012; glomerulonephritis, pyelonephritis, hypokalemia and hypercalcemia nephropathy and essential hypertension were abnormal. Low results may be diseases: uremia considerations Taboo before the test: maintain a normal diet and sleep. Inspection requirements: urine specific gravity is susceptible to a variety of factors, such as urine protein, sugar and other macromolecular substances, renal blood flow and endocrine function status. The high specific gravity of the high protein diet increased; the low protein, less salt diet, the proportion of malnutrition urine decreased. Urine osmotic pressure is less interfered by the above factors. The specific gravity of the urine is measured at 15 °C, the urine temperature is ±3 °C, the specific gravity reading should be ±0.003; the urine protein is +10 g/L, and the specific gravity reading should be -0.003. Inspection process Improved Fishberg method: 1. Eat a high-protein, low-liquid diet at 18:00 on the 1st of the test, the liquid content is 200ml, and then fast until the end of the test. 2. All night urine is discarded. 3. The bladder was evacuated from the morning of the test day, the urine was discarded, and the bed was continued. After that, the urine was urished once a day for 3 times. The urine specimens were placed in the container, and the urine volume, specific gravity and osmotic pressure were measured. The venous blood can be simultaneously measured for Posm. 4. Calculate the Uosm/Posm ratio, free water removal rate (CH2) or pure water removal rate of each urine, and calculate the formula and steps: V=CH2O+Cosm; CH2O=V-Cosm; Cosm=(Uosm/Posm) · V; CH2O = VV · (Uosm / Posm); = V · (1-Uosm / Posm); where V = urine volume (ml / h), composed of two parts of CH2O and osmotic concentration clearance (Cosm). Not suitable for the crowd Severe renal failure, uremia should pay attention. Adverse reactions and risks Severe renal failure, uremia patients with water can aggravate the condition.

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