Rules of preparation for analysis

  • The Laboratory of clinical and biochemical studies is fully responsible for accuracy of the received study results. Accuracy is influenced by the correctness of the procedure for blood sampling, the use of high-quality reagents, modern blood analyzers, disposable medical accessories, conduction of the laboratory quality control.
  • The client is responsible for consistency of the results obtained. It is important to follow the rules of preparation to analysis to obtain reliable study results. Depending on the clinical situation, they are determined by the physician or the general principles established for the testing of biological levels of laboratory parameters.
  • For the majority of indicators the blood should be tested till 11 am due to the cyclical nature of the changes in the nature and intensity of biological processes in the body (daily biorhythms).
  • An important condition for the laboratory study is blood test on an empty stomach, that is 8-12-hour period of hunger. It is forbidden to use chewing gum, refreshing lollipops, lozenges, etc. It is allowed to drink non-carbonated water without flavoring additives and aromatizer. Some tests (complete blood count, thyroid hormones, glycosylated hemoglobin) may be taken after a 4-hour hunger period, if the breakfast was light and did not contain butter, sausage and dairy products.
  • For blood test on lipid metabolism (cholesterol, lipoproteins, triglycerides) it is necessary to keep to a diet 1-2 days before the test without greasy, fried, spicy, salty food, alcohol, and not to overuse carbohydrates. The use of fats leads to their increase in blood serum in the chilosus form, that is the turbidity of the serum, and makes it unsuitable for most laboratory studies. The coloring products (carrots, beets, etc.) give indirect interference and overrate some indicators, so for blood test on bilirubin it is necessary to exclude these products from the diet for 1-2 days.
  • Blood for analysis is taken before the start of intake of medications, vitamins, supplements or not earlier than 10-14 days after the end of their use. If the medicine is not subject to cancellation, then the blood should be tested before the intake of medicine (injection) and it is necessary to inform the laboratory worker about it.
  • All blood tests are taken before X-ray radiography, ultrasound diagnostic and physiotherapy procedures.
  • It is desirable to give boiled water in portions to 150-200 ml to children up to 5 years within 30 minutes an hour before blood test.
  • For infants before blood test it is necessary to maintain the maximum possible pause between feeding.
  • On the eve of analysis it is necessary to exclude massages, sport, physical work, overcooling and overheating (saunas, baths).
  • Do not smoke an hour before blood test.
  • Female tests are taken on certain days of the menstrual cycle (LH, FSH is taken on 3-5 days of the cycle; estradiol is taken on 5-7 or 21-23 days of the cycle; progesterone is taken on 21-23 day of the cycle, testosterone and prolactin are taken on any day) if your doctor has not appointed other days. For blood test on prolactin it is necessary before one day to exclude sexual intercourse, palpation of the mammary glands, and to have blood sampling three hours after awakening. The psycho-emotional comfort is of great importance. When having tests of the reproductive panel, women must always indicate the day of the menstrual cycle or the period of pregnancy in order to take into account the cyclicity of hormonal oscillations.
  • For the blood test on PSA (prostatic specific antigen) it is necessary to refrain from ejaculation within 48 hours. It is advisable to take this analysis not earlier than in three days (optimally it is after 6-7 days) after any urological manipulations, digital rectal examination, ergometry, cystoscopy and colonoscopy, prostate massage. After the prostate biopsy it is optimally to have a test in three weeks. It is recommended to refrain from physical exercises that can affect the prostate gland (cycling), thermal influences (sauna) within three days before the analysis.
  • The glucose tolerant test is prescribed by a physician, and it is performed only at the normal and borderline level of glucose (at the upper limit of normal). During 3 days before the analysis, it is necessary to keep to the usual diet, but not to avoid the usual physical activity. In the course of the test, two blood samples are taken. The first sample is taken in the morning strictly on an empty stomach after 10-12 hour break in meal, and then a load of 75 grams of glucose dissolved in water is given. In 2 hours after the load the second blood sample is taken. During the test, the patient should sit comfortably or lie. It is forbidden to use chewing gum, refreshing lollipops, lozenges, etc. It is forbidden to smoke. It is allowed to drink non-carbonated water without flavors and aromatizer.
  • Preparation for blood test for prenatal screening in 1 and 2 trimesters is as follows. It is necessary to follow strictly recommendations of the doctor regarding the dates and time of ultrasound examination and blood test. Blood must be taken in the morning strictly on an empty stomach after 10-12 hour break in meal. Do not use chewing gum, refreshing lollipops, lozenges, etc. It is allowed to drink non-carbonated water without flavoring additives and aromatizer. As a rule, an ultrasound examination is prescribed after blood sampling on the same day or the next day. Prenatal screening for the first trimester is performed in the period of 8-13 weeks of pregnancy, prenatal screening of the second trimester is performed in the period of 14-19 weeks of pregnancy.
  • It is desirable to take all analyzes in a healthy condition (even a minor infection can affect the test results) if it is not about the control of treatment.
  • Stress, emotional excitement, physical activity (even climbing stairs) affects the tests and distort the study results. Before blood test it is recommended to sit calmly for 15-30 minutes.

ATTENTION! Different laboratories can use different research methods, measurement units and, consequently, reference (normative) values. For comparison and evaluation of your results to be correct, give the tests in the same laboratory at the same time, following the preparation rules.

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