Urine tests are prescribed for children for any reason, because this is the easiest way to pre-diagnose various diseases. Only here is it difficult to interpret the results to the uninitiated.
Urinalysis allows you to quickly and effectively identify a variety of diseases, not only the urinary system. In children, this method of research is used especially often - because a small child can tell about his feelings or answer the doctor's questions clearly.Message paths
Urine is formed in the kidneys from the blood plasma. The main processes occur in the nephron - a ball of fine capillaries. In it, through filtration, the so-called primary urine is formed. The process of formation of the final urine occurs in the renal tubules. At this stage, vital substances (vitamins, amino acids, electrolytes, etc.) from urine are absorbed back into the blood, and from the blood into the urine are output end products of metabolism and xenobiotics - alien to our body chemicals that we get with food. These are the components that must be removed (bilirubin, urea, etc.). Further, through the system of collecting tubules, urine enters the renal pelvis, then into the ureter, then accumulates in the bladder, and from there it emerges outward. The composition of urine is influenced by all the processes on this long path of transformation. If the mechanism fails at least on one site, it can contain substances that should not normally be present (or their number should be insignificant).Discount on age
When interpreting it is important to take into account the features of the anatomical structure of children. Thus, in neonates nephrons are structurally and functionally still immature. Also, the concentration ability of the kidneys is also reduced, so the urine of children of the first year of life has a low relative density. The vascular permeability of the nephrons themselves at this age is also increased, and glucose, proteins and even blood elements (red blood cells and leukocytes) appear in children's urine with a greater frequency than in adults.
However, in children over the age of the presence of such components is no longer a norm. Nevertheless, the formation of the urinary system does not occur immediately. For this very reason, in children of the first 2-3 years of life, the mechanisms of filtering blood plasma are poorly tuned, and the results of analyzes often require refinement and re-checking.Recipe for success
- Collect urine in special containers that are sold in pharmacies. Glass containers for food are not suitable for these purposes.
- For a general analysis, 50-100 ml of urine is required, for urine analysis according to Nechiporenko - not less than 10 ml.
- For most non-quantitative methods, which includes the general analysis of urine, an average portion of urine collected during urination at any time of the day is used. The first morning portion is the most concentrated, so it is easier to determine the substances present in the blood in minimal amounts. It is advisable to collect it if it is necessary to check all the indicators of the general analysis of urine to a single one.
- Urine for general analysis should be delivered to the laboratory within 1 hour, and the study should be carried out while the test material is still warm. In all other cases urine is stored in a glass container in a cool place, for example in a refrigerator.
- Before taking urine, it is necessary to conduct a thorough toilet of the external genital organs in both girls and boys.
To identify various ailments, there are several types of urinodiagnostics, among which the general analysis of urine is the most common. This study includes an assessment of the physico-chemical characteristics of urine and microscopy of the sediment. The results of the general analysis of urine are considered very informative: the doctor can judge the work of the organs of the urinary system, heart, liver, pancreas, gastrointestinal tract and pituitary gland.To cause the baby's urge to urinate, you can not only open the tap and issue invocative sounds, but also stroke his stomach or slightly press on the area just above the pubic area.
Color Fresh urine in a healthy child has a straw-yellow color, since it is pigmented with urochrome. With various diseases, options are possible. Pale color is observed in diabetes mellitus, dark yellow - with hepatitis and mechanical jaundice, red - with hematuria and hemoglobinuria. Sometimes the color changes due to food. Thus, carrot and beet pigments can stain urine in a reddish color, and rhubarb and tarragon are greenish.
Transparency Normally, the urine is clear. It can become cloudy if it contains many salts, cellular elements, bacteria, mucus and droplets of fat. The same will happen if the urine is settled for a long time: urate will drop out - salts of uric acid. But this does not affect the results.
Smell Fresh urine has a fuzzy, specific odor, and if it stays long in the air, an ammonia spirit appears due to microbial fermentation. Ammonia odor during urination may indicate severe forms of cystitis, feces indicate the presence of a vesicou rectal fistula. With diabetes, the smell of urine becomes apple notes. For all this, this indicator has only an indicative value for diagnosis.
Density In a healthy child throughout the day, the density of urine ranges from 1006 to 1025 g / l. This indicator depends mainly on the concentration of urea: the more urine, the lower its density, and vice versa. High density can be observed with kidney damage or violation of their nitrogen excretory function. Although the habit of drinking too little fluid leads to the same values. Low density is possible with abundant drinking, with various kidney diseases or a decrease in their concentration function, as well as diabetes insipidus.
pH Normally, a weakly acid reaction is recorded in fresh urine. For all ages, a value of 5-7 units is considered satisfactory. Only in newborns urine is more acidic: their pH varies in the range of 5.4-5.9. If the deviations from the extreme limits last a long time, this is a favorable factor for the precipitation of salts. Alkaline urine reaction is characteristic for bacterial inflammation, renal bleeding and a vegetarian diet. Acidic medium is established at feverish conditions, diabetes, fasting or eating large amounts of protein food, and also after physical exertion.
Ascorbic acid On the pathological acid reaction of urine, it is possible to judge the detection of ascorbic acid at a concentration of more than 2 mmol / l. Normally, 10-80 mg of vitamin C is released per day in small children. His absence is an indirect sign of his lack.
Protein In healthy children, urine practically does not contain protein. Normally its minimum amount is so negligible that a general analysis of it simply does not reveal. If the protein is found, it is either evidence of kidney and urinary tract diseases, or a sign of fever, excessive physical exertion, hypothermia. To make an accurate diagnosis, a thorough examination will be required.
Glucose In the urine of a healthy child, it is contained in traces (up to 0.002%) and during routine urinalysis is not determined. The amount of glucose increases in the case when carbohydrates do not have time to assimilate the body. Its presence in the urine suggests diabetes mellitus, hyperthyroidism, pheochromocytoma, brain concussion and other pathological conditions.
Acetone (ketone bodies) These substances are products of oxidation of fats and proteins. Normally, they are detected in very small quantities. High content of acetone is characteristic of severe forms of diabetes mellitus, although it is observed with repeated vomiting and after general anesthesia. In any case, deviations from the norm require medical attention.Diseases of the kidneys and urinary tracts often complicate the course of many childhood infections, and they can be detected by timely urine analysis.
Bile pigments (bilirubin) and bile acids. In the urine of healthy children, they are contained in minimal amounts. In the opposite case we are talking about liver damage.
Urobilinogen This bilirubin-derived substance is formed in the intestine and, when it re-enters the liver, it is completely destroyed. Samples for urobilin normally give a negative or weakly positive response. The amount of it increases with hepatitis of various genesis, hemolytic anemia.
Sterkobilinogen In contrast to urobilinogen, this component is the usual ingredient in urine, daily excretion of which is 0-6 mg.
Erythrocytes Normally, they can be no more than 3 in the field of view. Detection of altered red blood cells indicates their renal origin. Then the doctors think of polycystic kidney disease, nephritis and a tumor. Unchanged erythrocytes enter the urine from the urinary tract, so they speak of an infection in this zone.
Leukocytes Single leukocytes can be found in the urine of healthy children, especially in girls. If in the field of view there are more than 3-5 of them, this is a deviation from the norm. The presence of a large number of white blood cells is characteristic of cystitis, urethritis, balanoposthitis.
Bacteria In healthy children, urine is sterile. However, the presence of a small amount of bacteria in the urine is of no diagnostic importance. An indicative criterion is the content of 105 or more microbes in 1 ml of urine.
Epithelial cells Deformed cells of the epithelium of the mucous membrane of the urinary tract indicate inflammation or trauma (the latter can cause stones in the urinary tract). The presence of a small number of them does not matter.
Cylinders These are small elements of a cylindrical shape, consisting of a protein or cells and capable of precipitating. Normally, they are not detected. Only hyaline cylinders can occur in single quantities. In all other cases, it can be a serious damage to the kidneys and urinary tract.
Slime Slime in the urine appears with inflammatory diseases of the lower genito-urinary tract - urethritis, cystitis, vulvitis, balanoposthitis.
Fat Present in the sediment with nephrotic syndrome, diabetes mellitus. Normally not found.
Yeast fungi They are found in urine in large quantities after the application of antibiotics, which is in fact an undesirable complication of therapy. In this case, the question of the abolition of antibiotics is being decided.
Inorganic sediment The presence of salts in the urine sediment is of diagnostic value and does not depend on the pH of the urine. Uric acid, urate, calcium oxalate, calcium carbonate drop out in urine, which has acid reaction. Tripolyphosphates, phosphates, neutral phosphoric acid lime are precipitated in an alkaline medium. The appearance of calcium oxalate in the urine, oxalate crystals, sometimes in large quantities, is usually associated with eating foods with high levels of them. Phosphates and triphylphosphates are characteristic of cystitis. Leucine and tyrosine are found with severe liver damage, hematoidin - with bleeding in the urinary tract or with prolonged blood retention in the bladder. Cholesterol appears in the urine during the decay of cells. Cystine deposits are found in cystinuria, a rare hereditary disease associated with impaired protein metabolism.Important clarifications
Quantitative analysis of urine In addition to the general analysis of urine, there are more accurate methods for determining the blood elements, that is, leukocytes and erythrocytes. To similar researches doctors usually resort at suspicion on inflammatory process in urinary system. The most informative among them are urine tests for Amburge and Addis-Kakovsky. All urine is collected in one container, only in the first case for 3-4 hours, and in the second - for 12 or 24. Further calculation is carried out, how many leukocytes and erythrocytes the organism allocated for the taken period of time. For example, it is known that in norm for a day together with urine there can be allocated no more than 1 million erythrocytes and no more than 2 million leukocytes. From these figures, laboratory workers are repelled. A simpler, though less accurate, method that is most often used in children is the Nechiporenko fence technique. For the study, the average portion of urine is taken, then the number of blood elements per 1 ml of excreted urine without time is counted.Diagnostic test strips for express urine analysis, which are sold in pharmacies, give only preliminary results. And if the doctor is able to remove excess and see the error, parents can be very frightened. It is important to keep in mind that even a positive result is not a reason for panic.
Special tests Some characteristics that can be studied by urine are not included in the general analysis, therefore they must be ordered separately. The indicators are typed in a long list, but as an example, you can test for alpha-amylase. The presence of this substance allows us to assess the state of the pancreas. Another study, a Sulkovich trial, is used to detect calcium salts in the urine with a suspected overdose of vitamin D3. Similar analyzes are collected according to different schemes depending on the goal pursued.
Daily urine The most common technique for this large-scale type of urodiagnostics is the Zimnitsky test. Its essence is to determine the amount and relative density of urine, released every 3 hours during the day. The method makes it possible to assess the ability of the kidneys to concentrate and dilute urine. In addition, it is possible to determine the amount of isolated protein and glucose, calculate the eprctrocytes. The analysis is time-consuming and requires patience for parents. On the eve of the evening you will have to prepare 8 clean bottles and each number. The first morning urine (at 6-7 in the morning) must be drained. Beginning at 9 o'clock in the morning, the baby urinates every 3 hours in a separate bottle. At night it will have to awaken. At 6 or 7 o'clock (depending on when the assay was started), the last dose is collected the next morning and all 8 servings are sent to the laboratory, where the relative density of each of them is determined, night and day diuresis is measured (the amount allocated for the day and for night urine), and if necessary - the amount of protein in each container. A prerequisite for correctly assessing kidney function with this sample is observance of the usual water regime. It is very important to fix and the amount of fluid drunk by the baby during the day.
There are other types of daily analysis. So, on the prescription of the doctor biochemical studies of daily urine on sodium, potassium, phosphorus, calcium, urea, creatinine, lead, hormones and other indicators are carried out. The results are compared with the reference data. All daily urinalysis, in addition to the sample according to Zimnitsky, is collected according to the same scheme. At any convenient time (usually it is 9 am), the bladder is completely emptied and this first portion is drained. The entire urine is collected in the container, which will separate after the next day. At 9 am the next day the bladder is completely emptied again and the last portion of the urine is added to the container. Then calculate the total amount of urines released during this time, carefully shake it, pour 80-100 ml into a separate jar and send it to the laboratory. If by mistake at least one of the portions has not been collected, you must start all over again.
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