Urea nitrogen is a product of human protein catabolism, more than 90% is excreted through the kidneys, and the rest is excreted by the intestines and skin. When the kidneys have various lesions and the normal excretion function is destroyed, the blood urea nitrogen concentration is increased. The content of urea nitrogen in the blood is an important indicator of changes in renal function.

Basic Information

Specialist classification: urinary examination classification: biochemical examination

Applicable gender: whether men and women apply fasting: fasting

Analysis results:

Below normal:
Clinical significance is small, occasionally seen in acute liver atrophy, toxic hepatitis, lipidoid nephropathy.

Normal value:
Umbilical cord: 7.5-14.3mmol/L
Premature infant: 1.1-8.9mmol/L
Infants, children: 1.8-6.4mmol/L
Adult: 2.5-6.4mmol/L
>60 years old: 2.7-7.5mmol/L

Above normal:
(1) Kidney hyperplasia is seen in acute nephritis, chronic nephritis, toxic nephritis, severe pyelonephritis, renal tuberculosis, renal vascular sclerosis, congenital polycystic kidney disease and renal tumors. Especially for the diagnosis of uremia has special value, the degree of increase is directly proportional to the severity of the disease, such as BUN more than 9mmol / L in the azotemia period, BUN can exceed 20mmol / L in the uremic period, which is helpful for the estimation of the disease . (2) pre-renal hyperplasia is seen in congestive heart failure, severe burns, shock, gastrointestinal bleeding, dehydration, severe infection, diabetic acidosis, adrenal insufficiency, liver and kidney syndrome. (3) post-renal hyperplasia is seen in the increase of renal tissue pressure due to urinary tract obstruction, so that glomerular filtration pressure is reduced, such as prostatic hypertrophy, tumor compression caused by urethral obstruction or bilateral ureteral stones.

negative:

Positive:

Tips: Before the examination, the diet is light and alcohol is prohibited. Check that the morning is on an empty stomach. Normal value

The umbilical cord is 7.5 to 14.3 mmol/L (21 to 40 mg/dl).

Premature infants 1.1 to 8.9 mmol / L (3 ~ 25 mg / dl).

Infants and children 1.8 to 6.4 mmol/L (5 to 18 mg/dl).

Adults 2.5 to 6.4 mmol/L (7 to 18 mg/dl).

>60 years old 2.7 ~ 7.5mmol / L (8 ~ 21mg / dl).

Clinical significance

The following three situations can be seen:

1, renal hyperplasia seen in acute nephritis, chronic nephritis, toxic nephritis, severe pyelonephritis, renal tuberculosis, renal vascular sclerosis, congenital polycystic kidney disease and renal tumors caused by renal dysfunction. Especially for the diagnosis of uremia has special value, the degree of increase is directly proportional to the severity of the disease, such as BUN more than 9mmol / L in the azotemia period, BUN can exceed 20mmol / L in the uremic period, which is helpful for the estimation of the disease .

2, pre-renal increase seen in congestive heart failure, severe burns, shock, gastrointestinal bleeding, dehydration, severe infection, diabetic acidosis, adrenal insufficiency, liver and kidney syndrome.

3, post-renal increase is seen in the increase of renal tissue pressure due to urinary tract obstruction, so that glomerular filtration pressure is reduced, such as prostatic hypertrophy, tumor compression caused by urethral obstruction or bilateral ureteral stones.

cut back:

Clinical significance is small, occasionally seen in acute liver atrophy, toxic hepatitis, lipidoid nephropathy.

High results may be diseases: pyelonephritis, glomerulonephritis, uremia, acute nephritis, hepatorenal syndrome, chronic nephritis, systemic lupus erythematosus caused by mental illness

1. During the measurement process, all kinds of equipment and distilled water should be free from ammonia ion pollution, otherwise the result will be high.

2, the specimen is best to use serum.

3, elevated blood ammonia can make urea nitrogen results higher. Hemolysis specimens interfere with the assay.

4, high-protein diet is higher.

Inspection process

1. It must have a spectrophotometer with a thermostat or an automatic analyzer. The parameters are: temperature 30 ° C or 37 ° C, wavelength 340 nm, equilibrium time 30 s, reading time 30 s.

2. Take four test tubes, indicating the measurement, quality control, standards and blanks, and then follow the table.

The above tubes were sequentially added to the enzyme reagents one by one, and immediately after mixing, the change in absorbance (ΔA/min) was monitored on a spectrophotometer.

Not suitable for the crowd

Inappropriate people: Generally there are no people who are not suitable.

Adverse reactions and risks

When renal insufficiency increases blood urea nitrogen, there will be an increase in serum creatinine, and there will be clinical manifestations such as elevated blood pressure, loss of appetite, bleeding of gums, electrolyte imbalance, metabolic acidosis, abnormal urine test, etc. It is said that the increase of urea nitrogen alone cannot be said to be renal insufficiency.