Urinalysis according to Zimnitsky is an additional method of laboratory diagnosis, which helps to evaluate the work of the kidneys and to identify abnormalities in their work.
The technique was developed in 1924 by the therapist S. S. Zimnitsky. The most common indication for this sample is the suspicion of acute or chronic inflammatory processes in the kidneys. Such a test is relevant in case of renal failure developing on the background of diabetes mellitus and diabetes mellitus or hypertension.
This is one of the simplest techniques that does not require special medical equipment. Most often, it is resorted to when the patient is in a hospital. Patients with renal pathology urinalysis according to Zimnitsky appointed to control the activity of the paired organ of the urinary system.
Research according to the Zimnitsky method is carried out in addition to the general urine analysis, and allows to evaluate the concentration ability of the kidneys. Assigned analysis if available (or suspected presence):
- acute or chronic renal failure;
- chronic glomerulonephritis;
- chronic pyelonephritis.
As an additional diagnostic, urinalysis according to Zimnitsky is performed in diabetes mellitus, diabetes mellitus, CHF and hypertension.
In a healthy person, the kidneys excrete a large amount of "waste" fluid containing slags and other unwanted substances:
- uric acid;
- glucose isomers;
- protein elements, etc.
Indicators of urine concentration are compared with units of its relative density.
The purpose of such a sample is to determine the proportion of elements and compounds present in the urine during the day, since they can vary at different time intervals. Due to dynamic observation it is possible to evaluate the work of the kidneys. In a healthy person, the density of urine varies within 1003 - 1035 g / l.
The Zimnitsky analysis helps to determine the daily volume of urine, its density at different times of the day and its quantity released at different times. This is an indicator of renal activity.
How to collect urine for analysis on Zimnitsky?
Proper preparation for collecting urine ensures reliable results. Therefore, the patient should take this process as seriously as possible.
In children, the concentration of kidney function is reduced, therefore, the upper limit of daily diuresis in them is increased, and the relative density is lower.
Urine should be collected according to this algorithm:
- Prepare 8 sterile urine collection containers, number and indicate the time of urination.
- Urine should be collected 8 times a day every 3 hours throughout the day.
- After the end of urination, the container should be tightly closed with a lid and placed in a cool place.
- On a separate sheet you need to record the time and amount of fluid consumed and liquid food.
- If for 3 hours the patient did not have the urge to urinate, then the jar intended for the next portion of urine should be left empty.
- If the container intended for the next portion of urine is full, then the rest of the liquid must be collected in an additional sterile container. On it you need to specify the number of the container filled to the brim and the time of urination.
- After a day, all 8 jars need to be taken to the laboratory.
Urine collection should be carried out during the day at certain hours:
- from 9.00 to 12.00;
- from 12.00 to 15.00;
- from 3 pm to 6 pm;
- from 18.00 to 21.00;
- from 21.00 to 00.00;
- from 00.00 to 03.00;
- from 03.00 to 06.00;
- from 06.00 to 09.00
Time to wake the patient does not matter - the collection of biomaterial still begins at 9 am.
By preparation for the analysis it is necessary:
- refuse to take diuretic drugs;
- coordinate the use of any medication with a doctor;
- carry out washing of hands and genitals before each urination.
Diet with this analysis is not needed, as well as compliance with the drinking regime. Detailed recommendations on the collection of urine for research on the Zimnitsky method can be seen in the table:
What does the analysis of urine in Zimnitsky?
During the study, the laboratory assistant evaluates:
- Volume consumed during the liquid. To do this, the patient must keep a diary in which it is necessary to record the amount of fluid consumed and the liquid food consumed.
- The volume of daily urine. For its determination, the amount of urine from all 8 containers is summed up.
- The ratio of fluid intake to daily diuresis. Normally, 65 to 80% of water is excreted in the urine during the day. The remaining amount is consumed by the body and excreted in sweat.
- The ratio of night and day diuresis. Normally, a person does not have the urge to urinate at night. During the first morning emptying of the bladder from the body, a third of the fluid is removed from the total daily diuresis.
- The period of time during which the formation of urine occurs after drinking a large amount of fluid. Healthy kidneys quickly filter the volume of water that has entered the body, and just as quickly remove it from the urine, thereby removing unnecessary, "waste" elements from the body.
- Variations of urine density: in different portions of urine, this indicator should not differ too much amplitude.
- The density of urine in the control capacity and the average density of the total daily diuresis should be within the normal range.
The main indicator of analysis by the Zimnitsky method is the specific gravity of urine: the ratio of the amount of fluid and the solid part of urine. This solid part is formed by nitrogenous compounds, organic elements, salts, acids.
If a significant deviation in urine density is noted, or there are sharp and significant fluctuations in specific gravity in different portions of urine, this will be considered an unfavorable diagnostic sign. It may indicate a variety of different diseases that additional research will help identify.
Interpretation of the results of the Zimnitsky test
The norms of indicators of urine according to the method of research of urine, developed by Zimnitsky, are stated in the table below.
|Parameter / criterion||Normal values|
|Daily diuresis||1.5 - 2 l|
|The ratio of the injected fluid and the volume of daily urine||65-80%|
|The amount of urine highlighted during the day||2/3|
|The amount of urine allocated at night||1/3|
|Significant increase in diuresis after drinking large amounts of fluid.||+|
|Fluctuations of urine density in tanks||From 1003 to 1035 g / l|
|Density of urine in 1 or several containers||1020 g / l|
|Total urine density||Less than 1035 g / l|
Usually, in the form with the results, in parallel with the data obtained, the laboratory indicates the reference values of these indicators.
Low urine density (hypostenuria)
If the total density of urine is below 1012 g / l, then such a deviation is called hypostenuria. Reduced daily urine density may appear when:
- progressive renal diseases (chronic renal amyloidosis, pyelonephritis, glomerulonephritis, hydronephrosis);
- chronic pyelonephritis, which is in the acute phase;
- heart failure 3 - 4 severity;
- diabetes mellitus;
High density urine (hypersthenuria)
Hypersthenuria (high density urine) is referred to when the specific gravity in one of the eight tanks with biological materials exceeds the permissible maximum of 1035 g / l. An increase in the density of urine is observed in patients with:
- sickle cell anemia;
- gestational toxicosis - early or late;
- acute or chronic form of glomerulonephritis.
An increase in urine density is also observed in patients undergoing a blood transfusion procedure.
Increase the volume of daily urine (polyuria)
Polyuria - a deviation in which the daily volume of urine, in the normal range of 1.5 - 2 liters, significantly exceeds these figures. Such a disorder of urinary function may indicate the presence of diabetes mellitus or diabetes mellitus, or renal failure.
Reduced daily urine (oliguria)
If the volume of daily urine is reduced to less than one and a half liters, then this deviation is called oliguria. In some cases, such a violation is not pathological, and may be the result of severe stress, excessive sweating when a person is in a hot environment or the use of some GCS. But sometimes oliguria is a sign:
- heart failure;
- severe stage of renal failure.
The predominance of night urination over daytime (nocturia)
Night diuresis in normal amounts to 1/3 of the total daily volume of urine. If, according to the results of the Zimnitsky test, this indicator is higher, then the reason may lie in:
- diabetes mellitus or diabetes mellitus;
- prostate dysplasia;
- impaired concentration of kidney function;
- renal, heart failure.
Daily diuresis below 50 ml or absent (anuria)
Anuria is a condition in which daily diuresis is 200 to 300 ml, or completely absent. It can occur when:
- acute blood loss;
- violation of the movement of urine through the urethra;
- bladder function disorder.
Thus, a seemingly simple urine test plays an important role in the diagnosis of various diseases and pathological conditions. However, the patient should understand that panic in the case of obtaining "suspicious" research data is premature. An accurate diagnosis can only be made on the basis of a comprehensive diagnosis, and the analysis according to Zimnitsky is one of its components.