Blood urea nitrogen (BUN)

Blood urea nitrogen (BUN) determination is an auxiliary examination method for checking whether urinary function is normal. Serum non-protein nitrogen (NPN) includes nitrogen in nitrogenous substances such as urea, uric acid, creatinine, amino acids, terpenoids, amines, and hydrazine. BUN is the main component of NPN, accounting for half (more than 50%). BUN is more sensitive than NPN in reflecting renal failure. The detection of renal function was replaced by the measurement of blood urea nitrogen (BUN), which was now discarded. Basic Information Specialist classification: urinary examination classification: urine / kidney function test Applicable gender: whether men and women apply fasting: not fasting Tips: It is best not to have breakfast before the examination, and at least three days before the examination should be light diet, do not drink alcohol, overeating or excessive fatigue, so as not to affect the test results. Normal value Adult 3.2 ~ 7.1mmo] / L. Infants and children 1.8 to 6.5 mmol/L. Clinical significance Abnormal results: increased acute and chronic nephritis, severe pyelonephritis, acute and chronic renal dysfunction caused by various causes, heart failure, shock, burns, water loss, massive internal bleeding, adrenal insufficiency, prostatic hypertrophy, chronic urinary tract obstruction Wait. People who need to be examined: Patients suspected of being kidney disease. Precautions Taboo before the test: It is best not to have breakfast before the test, and the diet should be light at least three days before the test, do not drink alcohol, overeating or excessive fatigue, so as not to affect the test results. Requirements for examination: The patient actively cooperates with the doctor and the doctor carefully operates to avoid the result. Inspection process Take the patient's blood sample and determine if blood urea nitrogen (BUN) is within the normal range. Urea is the main end product of human protein metabolism. Amino acid deamination produces NH3 and CO2. Both of them synthesize urea in the liver, and produce 0.3g of urea per gram of protein. The nitrogen content in urea is 28/60, which is almost half-half. Usually, the kidney is the main organ for excreting urea. After the glomerular filtration, urea can be reabsorbed in each segment of the small tube, but the faster the urine flow rate in the renal tubule, the less reabsorption, that is, the maximum clearance rate is reached. As with serum creatinine, blood urea nitrogen can be in the normal range in the early stages of renal impairment. When the glomerular filtration rate drops below 50% of normal, the blood urea nitrogen concentration rises rapidly. Under normal circumstances, the ratio of blood urea nitrogen to creatinine (BUN/Scr) is about 10, high protein diet, high catabolic state, water shortage, renal ischemia, hypovolemia, and some acute glomerulonephritis. The ratio can be increased, even up to 20~30; while the low protein diet and liver disease often reduce the ratio, which can be called hypoxemia. Not suitable for the crowd Inappropriate people: Generally there are no people who are not suitable. Adverse reactions and risks No related complications or hazards.

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