Analysis for creatinine - why, preparation, delivery, decoding

What is creatinine

Creatine is destroyed in the muscles, and the residual product is creatinine.

Creatine is synthesized in the kidneys, pancreas and liver; in human muscles it becomes creatine phosphate . When it disintegrates, the energy necessary for a person is released. Thanks to this energy, nerve and muscle cells can function normally. The amount of creatine in the blood is different for all people, it depends on the amount of muscle a person has, so women have the same numbers (less), and men have different numbers.

The amount of creatinine in the blood does not depend on his lifestyle; it also does not change during the day. The body removes it using urine. But, if a person has something wrong with his kidneys, then the amount of creatinine increases. Therefore, in order to determine whether a person’s kidneys are functioning well, they are often asked to take a creatinine test.

Who is prescribed the analysis?

A blood test is done to find out the amount of creatinine in the blood. The doctor decides whether a person needs this study or not.

But usually a creatinine test is prescribed in the following cases:

A thorough examination is necessary, because the patient decided to become a kidney donor.
The doctor suspects that the person is developing kidney or muscle disease.
The doctor must prescribe a special drug to the patient, and he needs to decide on the dosage.
The specialist, based on the following symptoms, thinks that the patient has an increased concentration of creatinine in the blood: he has difficulty breathing, is bothered by aching pain in the lower back, a feeling of heaviness appears, the person complains of fatigue, and has a confused consciousness.
There are all the symptoms of kidney dysfunction: the patient has problems sleeping, weakness, he gets tired quickly, eats poorly, he has swelling in the wrists and face, problems with urination (burning, intermittency), it has changed color, has become foamy, pain in the lumbar region etc.

Preparation

How to properly prepare if you are scheduled for a creatinine test? There are several points that must be observed:

2 days before the test, no physical activity, i.e. You will have to give up fitness, dancing, training, you can’t run or lift weights. Before going to the clinic, you should not quickly climb the stairs and somehow load yourself.
In the evening, before taking a creatinine test, you should not have dinner with fatty foods, or at least you need to reduce the amount as much as possible. It is also undesirable to eat foods that contain a lot of protein. The day before the examination, you should not drink alcoholic beverages, abuse coffee or strong tea.
Blood is taken for analysis on an empty stomach, which means that a person should not eat anything for at least 8 hours, but it is better if abstinence from food is longer (10-12 hours).
In the morning before taking the test, you cannot drink tea or juice, as well as coffee, but you are allowed to drink some still water.
If possible, you should also give up medications. You can talk about this separately with your doctor. You should also not take painkillers, which could cause the test to be false. These are phenacytin, aminopyrine, and some anti-inflammatory drugs.
Before going for analysis, you should not smoke for 1-2 hours or at least 30 minutes.
You should not worry at the time of donating blood; before doing so, you need to relax and sit quietly for at least a quarter of an hour.

How to properly prepare for a laboratory test

95190 10 October

IMPORTANT!

The information in this section cannot be used for self-diagnosis and self-treatment.
In case of pain or other exacerbation of the disease, diagnostic tests should be prescribed only by the attending physician. To make a diagnosis and properly prescribe treatment, you should contact your doctor. See also other conditions for preparation for analysis.

Dear patients! Please note that it is recommended to donate blood for laboratory tests in the morning on an empty stomach, after an 8-12 hour overnight fasting period. If the patient is unable to come to the laboratory in the morning, blood should be donated after 6 hours of fasting, eliminating fats in the morning meal.

Timely and accurate diagnosis of various diseases is impossible without laboratory tests. There are no manifestations of the disease yet, but blood counts are already “signaling”: “Attention! Anxiety!". According to the World Health Organization (WHO), laboratory tests provide 60–80% of diagnostic information about a patient. Of course, a diagnosis is not made based on just one laboratory analysis; it is compared with the clinical picture, with data from other studies and observations. Laboratory analysis suggests the direction for further search. Therefore, regular preventive examinations are the key to timely initiation of treatment, and proper preparation for tests in a modern laboratory is an accurate diagnosis.

Laboratory doctors of the INVITRO Independent Laboratory have prepared a number of recommendations, compliance with which will allow you to obtain the most accurate results.

How to prepare for blood tests
How to prepare for a urine test
Rules for collecting stool for dysbacteriosis

Preparing the patient for the blood donation procedure

A number of tests are done on an empty stomach. For example, biochemical (glucose, cholesterol, bilirubin, etc.) and serological tests (syphilis, hepatitis B), hormones (TSH, parathyroid hormone), etc. “Fasting” is when at least 8 hours pass between the last meal and taking blood (preferably at least 12 hours). Juice, tea, coffee, especially with sugar, are also food, so you will have to be patient. You can drink water.
Strictly on an empty stomach (after a 12-hour fast) you should donate blood to determine lipid profile parameters: cholesterol, HDL, LDL, triglycerides.
If you have to take a general blood test, your last meal should be no later than 1 hour before donating blood. Breakfast may consist of unsweetened tea, unsweetened porridge without butter and milk, and an apple.
It is advisable to exclude fatty, fried and alcohol from the diet 1 - 2 days before the examination. If there was a feast the day before, reschedule the laboratory test for 1-2 days. Avoid smoking an hour before blood collection.
The content of many blood tests is subject to daily fluctuations, so for some studies blood should be taken strictly at a certain time of day. So, blood tests for some hormones (TSH and parathyroid hormone), as well as for iron, are given only before 10 am.
When donating venous blood, it is necessary to exclude factors that influence the research results: physical stress (running, climbing stairs), emotional arousal. Therefore, before the procedure you should rest for 10-15 minutes in the waiting room and calm down.
It happens that the doctor ordered a test, but for various reasons it is difficult for the patient to come to the medical office (illness, pregnancy, lack of time, etc.) In this case, it is enough to call the INVITRO Laboratory Emergency Service by calling tel. , and our procedural team will arrive at a place and time convenient for you.
Blood is taken for analysis before starting to take medications (for example, antibacterial and chemotherapy) or no earlier than 10 to 14 days after their discontinuation. The exception is when they want to study the concentration of drugs in the blood (for example, valproic acid, anticonvulsants). If you are taking medications, be sure to tell your doctor about this.
Blood should not be donated after X-rays, rectal examinations, or physical therapy procedures.
During hormonal studies in women of reproductive age (from approximately 12 to 13 years of age and before the onset of menopause), the results are influenced by physiological factors associated with the stage of the menstrual cycle. Therefore, when preparing for examination for the hormones FSH, LH, prolactin, estriol, estradiol, progesterone, the phase of the cycle should be indicated. When conducting a test for sex hormones, strictly adhere to the recommendations of your doctor about the day of the menstrual cycle on which you need to donate blood.
When performing tests for the presence of infections, it should be taken into account that depending on the period of infection and the state of the immune system, any patient may have a negative result. But, nevertheless, a negative result does not completely exclude infection. In doubtful cases, re-analysis is recommended.
Different laboratories may use different research methods and units of measurement. To ensure that the assessment of your results is correct and the results are acceptable, do the tests in the same laboratory, at the same time. Comparison of such studies will be more correct.

Preparing the patient for the urine donation procedure Collecting urine for general analysis in a container with a preservative

From the medical laboratory office, obtain a container with a white cap and a test tube with an adapter.
On the eve of the test, it is recommended not to eat vegetables and fruits that can change the color of urine (beets, carrots, etc.), and not to take diuretics. Before collecting urine, it is necessary to perform a thorough hygienic toilet of the genitals. Women are not recommended to take a urine test during menstruation.
Collect approximately 50 ml of morning urine in a container (with a white lid). To properly conduct the study, during the first morning urination, release a small amount of urine (the first 1 - 2 seconds) into the toilet, and then, without interrupting urination, place a urine collection container into which to collect approximately 50 ml of urine.
Immediately after collecting urine, close the container tightly with a screw cap.
Insert the adapter into the container, pressing its sharp end into the recess on the container (Fig. No. 1).
Place the test tube downwards with the rubber stopper into the recess on the wide part of the adapter, and the test tube will begin to fill with urine. After urine stops flowing into the test tube, remove the test tube from the adapter (Fig. No. 2, No. 3).
Invert the tube several times to better mix the urine with the preservative (Fig. No. 4).
Deliver the test tube with urine to the laboratory during the day (according to the blood test schedule). If it is not possible to immediately deliver urine to the medical office of the laboratory, then the test tube with urine should be stored at a temperature of +2...+8°C.

Collection of 24-hour urine for biochemical analysis
24-hour urine is collected. The first portion of urine in the morning is removed. All subsequent portions of urine excreted during the day, night and the morning portion of the next day are collected in one container, which is stored in the refrigerator (+4...+8°C) during the entire collection time (this is a necessary condition, since at room temperature it is significantly glucose levels decrease). After completing urine collection, accurately measure the contents of the container, be sure to mix it and immediately pour it into a small jar (no more than 5 ml). Bring this jar to the laboratory for testing. You don't need to bring all the urine. On the referral form you need to indicate the daily volume of urine (diuresis) in milliliters, for example: “Diuresis 1250 ml”, also write down the patient’s height and weight.

Before 10 am (1st or 2nd morning urine sample), a urine sample is taken to determine DPID.

Collection of urine for the analysis “Catecholamines in urine”

To conduct the study, you must obtain preservative powder and a urine container from any INVITRO medical office. Before routine urine collection to determine catecholamines, for 3 days you should not use drugs containing rauwolfia, theophylline, nitroglycerin, caffeine, ethanol, if possible, do not take other medications, as well as food products containing serotonin (chocolate, cheeses and other dairy products , bananas), do not drink alcohol. Avoid physical activity, stress, smoking, pain, which causes a physiological rise in catecholamines. First, a preservative powder from a test tube obtained in the laboratory is poured into the bottom of a clean container into which urine will be collected. The bladder is emptied (this portion is poured out), the time is noted and urine is collected in a container with a preservative exactly for 24 hours; the last urination into the container should be 24 hours from the time recorded (for example, from 8.00 am to 8.00 am the next day). It is possible to collect urine over 12, 6, 3 hours or a single portion, preferably during the daytime. At the end of the collection period, measure the total volume of urine excreted per day, mix it, pour some into a specially issued container and immediately bring it for examination. When submitting material, be sure to note the time of collection and the total volume of urine.

Remember that only the attending physician, who has the opportunity to observe the patient’s condition and explain the need to prescribe certain tests, can draw up an optimal laboratory examination program and evaluate the test results.

IMPORTANT!

The information in this section cannot be used for self-diagnosis and self-treatment. In case of pain or other exacerbation of the disease, diagnostic tests should be prescribed only by the attending physician. To make a diagnosis and properly prescribe treatment, you should contact your doctor.

Analysis result

If a test for creatinine shows that the concentration of this substance is increased, then this indicates that the person has some kind of disease related to kidney function, for example, urolithiasis, or pathology of the muscular system. But this is not always a sign of a disease; this result also happens in the following cases: