RULES OF PREPARATION FOR BLOOD TEST
The main factors that can affect the result of blood tests:
Medications: the impact on the results of laboratory tests from them can be different and not always predictable.
Food intake: both direct (due to absorption of food components) and indirect effects are possible (shifts in hormone levels in response to food intake, changes in sample turbidity in response to an increase in the content of fat particles).
Smoking: changes the secretion of some biologically active substances.
Alcohol: affects most metabolic processes.
Physical and emotional overload: cause biochemical and hormonal changes.
The phase of the menstrual cycle in women: is important for several hormonal studies. Before the study, you should check with your doctor the optimal days for taking a sample to determine the level of follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin, progesterone, and estradiol.
Instrumental examinations, and physiotherapy: may cause temporary changes in some laboratory parameters.
Time of day when taking blood: many laboratory parameters can fluctuate during the day, which is associated with the existence of daily rhythms of human activity. Fluctuations in various biochemical and hormonal parameters are expressed to a greater or lesser extent; reference values (limits of "normality") usually reflect the statistical data obtained during blood sampling in the morning under standard conditions.
General rules in preparation for the study:
- It is necessary to donate blood in the morning, on an empty stomach (from 8 to 14 hours without eating, water is allowed to be drunk as usual), 24 hours before the test, and food overload should be avoided.
- If you are taking any medications, you should consult your doctor about the feasibility of conducting the study while taking medications or the possibility of canceling the drug before the study.
- Exclude alcohol intake on the eve of the study.
- Do not smoke for 1 hour or more before the study.
- Exclude physical and emotional stress on the eve of the study.
- After arriving at the medical laboratory, it is recommended to rest for 10-15 minutes before taking blood samples.
- It is undesirable to donate blood for laboratory testing soon after physiotherapy procedures, X-ray examination, and other medical procedures.
- Children under 5 years old should be given boiled water (in portions up to 200 ml, for 30 minutes) before donating blood.
- For infants, before donating blood, the maximum possible pause between feedings should be maintained.
- When monitoring laboratory parameters in the dynamics, repeated tests are recommended to be carried out in the same conditions: in the same laboratory, at the same time of day, etc.
Minimum requirements: tests for infections and emergency tests are preferably performed on an empty stomach (4-6 hours).
The dietary regime, special requirements: only on an empty stomach, after 12-14 hours of fasting, blood should be taken to determine the parameters of the lipid profile (cholesterol, HDL, LDL, triglycerides, VLDL, lipoprotein A); glucose tolerance test is performed in the morning on an empty stomach after 8-14 hours of fasting.
It should be remembered that when performing tests for infections, depending on the immune status of the patient and the period of infection, a negative result may be obtained, which, however, does not completely exclude the presence of infection. In doubtful cases, it is recommended to repeat the analysis.
Additional recommendations for preparation:
Prolactin: no more than 2 hours should pass after sleep, blood should be taken in the morning at rest, excluding breast palpation before the test.
Testosterone: blood sampling is preferably carried out before 10:00 am (due to daily biorhythms).
Prostate-specific antigen (PSA):
- it is recommended to abstain from sexual intercourse for 5-7 days before the test;
- after mechanical effects on the prostate, it is advisable to wait at least 2 weeks before taking a PSA blood test, and after a prostate biopsy _ at least a month.
Prothrombin index (PTI):
- it is advisable to repeat the blood test for PTI at the same time;
- patients taking hormonal drugs should not violate the schedule on the day of the test unless there are special recommendations from the doctor.
RULES OF PREPARATION FOR FECAL EXAMINATION
(peculiarities of preparation for fecal microbiological examination are described below, in the relevant section)
Mandatory conditions for fecal examination:
- Stool is collected in a clean container (15 g is enough).
- The stool should be delivered to the laboratory and examined no later than 8-12 hours after defecation.
- Stool should be stored at a temperature of 3-5 ° C (in the refrigerator).
- Freezing is not allowed.
- A loosely closed container is not allowed.
- On the container with feces it is necessary to write the name, initials, and year of birth.
- When taking feces simultaneously for worm eggs and coprogram, it is possible to take it in one container.
For the analysis of feces for hidden blood is necessary:
- Examine the feces obtained after spontaneous defecation.
- 3 days before the test, exclude meat, liver, fish, greens, vegetables, tomatoes, and other foods containing iron from the diet.
- Stop taking medications (iron-containing, ascorbic acid, aspirin, etc.).
The examination is not recommended:
Within 2 weeks after instrumental examinations of the gastrointestinal tract or medical procedures (colonoscopy, rectoromanoscopy, intestinal cleansing with enemas, etc.)
Women during menstruation.
In case of bleeding from hemorrhoids, hematuria, or after excessive straining during defecation.
If there are impurities of urine or genital discharge.
It is recommended to examine the feces three times, and each time the samples should be taken from two different places of the fecal mass. The stool is collected in an amount not exceeding 1/3 of the container volume. It is necessary to deliver the container with feces within 2 hours from the moment of taking the biomaterial.
RULES OF PREPARATION FOR URINE EXAMINATION
Thorough toilet of the external genital organs:
Women: before urine collection, insert a gynecological tampon into the vagina. It is not recommended to do urine analysis during menstruation (optimally _ 2 days after its end).
Men: thorough toilet of the external genitalia with the opening of the glans penis.
Bedridden patients are pre-washed with a weak solution of potassium permanganate (or its substitute).
Urine from the vessel, pot, etc. should not be taken!
In infants, after a thorough genital toilet, it is advisable to collect urine in a urine collector.
Urine squeezed out of a diaper is not subject to examination!
- Urine is collected in a special container or cleanly washed glassware.
- To increase the reliability of the results, it is not recommended to take several urine tests in one day.
Your name, initials, and year of birth must be written on the urine container.
General urine analysis:
- Urine is collected in the morning on an empty stomach immediately after sleep. Only morning urine taken in the middle of urination is collected, as it is more concentrated, and pathological elements that have accumulated in the kidneys and urinary tract overnight are washed out.
- Catheter or bladder puncture can be used only in extreme cases. Urine cannot be taken from a catheter that has been used for a long time!
- It is not recommended to consume alcohol, spicy, salty foods, as well as foods that change the color of urine (for example, beets, carrots) on the eve of the test (10-12 hours);
- As far as possible, diuretics should be excluded.
- Before taking the test, it is necessary to make a thorough toilet of the external genital organs.
- Women are advised to do the test before menstruation or 2 days after it.
- Urine is collected in a dry, clean, well-washed plastic or glass container (optimally: sterile disposable urine container) with a volume of at least 10 ml, which is tightly closed with a lid.
- The collected material should be delivered to the laboratory as soon as possible (during prolonged storage, uncharacteristic salts precipitate in the urine, which interferes with the accurate description of the sediment, as well as possible contamination of the sample with extraneous bacterial flora. Bacteria in the urine begin to release ammonia and absorb glucose, resulting in a change in the pH of the medium. In addition, bile pigments contained in the urine begin to break down in the light).
Urine analysis by Nechiporenko:
The purpose of the analysis is to detect a hidden inflammatory process in the urinary system and determine the number of blood cells (leukocytes, red blood cells) and cylinders (clots of protein or cellular elements). Beforehand, do not forget about a thorough toilet of the external genital organs (elements of inflammation of the urethra and external genital organs can get into the urine, which will complicate the correct diagnosis). For the study, it is necessary to collect the middle part of the morning urine (approximately 50 ml) in a clean, dry plastic or glass container that is tightly closed with a lid.
RULES OF PREPARATION FOR MICROBIOLOGICAL RESEARCH
Microbiological research. General requirements
- Usually, the manipulation is performed by medical staff.
- Material collection should be carried out before the start of treatment with antibacterial, antifungal, and immunobiological drugs.
- Material collection can be carried out at least 3 days after the end of the course of treatment with antibacterial or immunobiological drugs.
Additional conditions for the collection of material for microbiological research
- Immediately before collecting milk, it is necessary to thoroughly treat hands and mammary glands with soap and then _70% alcohol or vodka.
- Before collecting the material, it is advisable to massage the dense areas of the mammary glands.
- The first few drops of milk should be drained and disposed of.
- After that, it is necessary to decant the milk into 2 sterile plastic or glass containers (separately for the left and right breast).
- The containers must be signed: indicate the name, initials, and year of birth and indicate in which container the milk is from which breast.
- Containers with milk are tightly closed with lids, packed in separate, clean disposable bags, and delivered to the laboratory.
- Sputum for general analysis is collected by the patient himself in the morning before meals in a specially prepared sterile container with a lid. Before sputum collection, the patient should thoroughly rinse the oropharynx with boiled water, and remove saliva from the mouth and mucus from the nose. The collected sputum should not contain impurities of saliva and nasopharyngeal secretions.
- The patient should inhale deeply through the mouth, and then make a long cough. The resulting sputum is spat into a container (repeat several times if necessary).
- If it is not possible to collect the material, inhalation with a warm 10% sodium chloride solution (10 g of table salt per 1 liter of boiled water) or a solution containing 150 g of sodium chloride (table salt) and 10 g of sodium bicarbonate (baking soda) per 1 liter of water should be used before sputum collection.
Material from the pharynx:
- Pharyngeal swab is collected on an empty stomach or no earlier than 3-4 hours after a meal.
- It is necessary to exclude oral hygiene (do not brush your teeth).
Material from the eye:
- All medications and procedures (general and topical) should be discontinued before sampling (6-8 hours).
- Do not wash your eyes on the day of sampling.
- Do not rinse nasal passages before swabbing.
Material from wounds/vesicles, pustules, and boils:
- Before taking the material, the skin around the wound should be treated with alcohol or any other antiseptic. Necrotic masses, detritus, and pus are removed with a sterile napkin.
- From an unopened wound, the material is taken with a syringe with a wide-diameter needle. The selected material is transferred to a sterile tube with a transport medium.
- From opened wounds, the material is taken with a sterile swab in a circular motion from the center to the periphery of the wound surface / from vesicles, pustules, and boils.
Material from the vagina/cervical canal:
- Sexual intercourse must be excluded for three days.
- Douching and the use of vaginal suppositories, ointments, and tampons should be excluded for three days before sampling.
- You should refrain from urinating 3 hours before sampling.
- During menstruation and for three days after its end, it is forbidden to donate material.
Material from the urethra:
- You should refrain from sexual intercourse and ejaculation for three days.
- It is necessary to refrain from urination for three hours before the collection of the material.
Prostate secretion material:
- 24 hours before the collection of the material it is necessary to exclude heat exposure to the genital area (bath, sauna, etc.).
- The material is collected by the patient himself in a sterile container.
- It is necessary to exclude heat exposure to the genital area (bath, sauna, etc.) 24 hours before sampling.
Feces for pathogenic flora (intestinal dysbiosis):
- Feces is collected by the patient himself.
- The material for the study is collected in a sterile, dry wide-mouth container or in a special industrial container.
- Feces for dysbiosis is collected before the start of treatment with antibacterial, chemotherapeutic drugs, pre-, and probiotics (if not possible, then only 2-3 days after the drugs are discontinued).
- Alcohol, dairy, and other products that enhance fermentation processes in the intestine should be excluded 2-3 days before the test.
- 3-4 days before the collection of material, it is necessary to stop the administration of rectal suppositories and enemas, as well as taking laxatives, castor and petroleum jelly, and barium (during X-ray examination).
- It is advisable to perform a fecal examination not earlier than 2 days after the X-ray examination with the use of contrast agents.
- The study should be carried out before performing rectoromanoscopy and other diagnostic manipulations in the intestine and stomach.
- Collect the morning portion of stool (it is forbidden to collect feces from the toilet bowl).
- Feces is collected on a sterile surface: for example, on a dense, non-absorbent, sterile paper (at home, iron with a hot iron and fold the ironed surface inward) or in a pot or vessel (first rinse well with a sponge and soap and rinse repeatedly with tap water, then pour boiling water and cool). Do not treat the vessel with any disinfectants!
- Feces is taken from the middle portion in an amount not exceeding 1/3 of the container volume.
- The container should be tightly closed with a lid and packed in a clean disposable bag.
- The container should contain the name, initials, year of birth, date, and time of collection.
- Stool should be delivered to the laboratory as soon as possible, but no later than 8-12 hours after defecation.
- The material should be stored at a temperature of 3-5 oC (in the refrigerator).
- Freezing of the material is not allowed.
- A loosely closed container is not allowed.
- Do not collect urine from bed linen or from the urinal.
- Before the analysis, the patient should perform a thorough toilet of the external genital organs (women should close the entrance to the vagina with cotton wool or a sanitary tampon).
- For bacterial testing, an average portion of urine is taken (not necessarily in the morning).
- Urine is collected in a sterile container.
- It is recommended to deliver the urine to the laboratory within 2 hours, storage is allowed at a temperature of 2-6 ° C for no more than 2-3 hours.
PREPARATION FOR MICROBIOLOGICAL EXAMINATION FOR DERMATOPHYTES AND MYCELIAL FUNGI
The material should be selected by a doctor.
Antifungal drugs should be discontinued for 7 days.
Local treatment (ointments, paints, etc.) should be stopped 3 days before.
Skin and nails shall be pre-washed with laundry soap and air-dried.
In the acute process, skin scales are taken from the periphery of the lesion and the cover of the blisters.
In chronic process - from the surface of the entire lesion.
Skin scales are removed with a sterile scalpel, and the skin between the fingers and blister is covered - with sterile tweezers.
Short, broken, twisted hair; hair 5-10 mm long with a whitish sheath at the root; long whitish hair, as if sprinkled with flour, is taken from the alopecia areata. The hair is removed with tweezers. Also in the thickness of the skin scales, there is short twisted hair in the form of black specks, which are removed with a needle or scalpel.
The affected edge of the nail is cut with an alcohol-treated razor or a sterile scalpel, all cut pieces are collected. A scrape is made through the incision from the depth of the affected nail plate. You can use a drill and take a sample through the "window".
Samples are placed in any sterile container (urine collection container, Eppendorf tubes, Petri dishes with a diameter of 30 mm).
Preparation of the patient for examination for demodicosis (for the presence of Demodex mite)
Washing with soap for 3 days before the test.
Use of cosmetics.
Use of ointments less than 10 days before the procedure.
Rules for selecting biopsy material for H. pylori testing
Biopsy material for the isolation of H. pylori should be obtained before the start of antibiotic therapy or before the appointment of a new antibiotic regimen (if the previous treatment is ineffective). Before obtaining a biopsy for culture, it is recommended to stop taking proton pump inhibitors, bismuth preparations, and antibiotics for 14 days. Taking a biopsy from the gastric mucosa for bacteriological examination for H. pylori does not exclude other diagnostic methods (for example, a rapid urease test or histological examination). A negative result of a rapid urease test or other methods of diagnosing H. pylori does not exclude the possibility of isolating this pathogen by the bacteriological method.
In order to increase the sensitivity of the method (the probability of detecting H. pylori), during the endoscopic examination, two biopsy samples are taken from the antrum of the stomach (2-3 cm from the gastric gate along the anterior and posterior walls) and two _ from the body of the stomach (10 cm from the cardia along the great curvature). The biopsy is taken in places with the most pronounced hyperemia and edema. Taking material from the bottom of ulcers and erosions, as well as from their edges is a mistake because in these areas there are no epithelial cells that provide adhesion and colonization of H. pylori.
Storage and transportation of material before primary seeding
Four biopsies are immediately placed in a transport tube. If the time from taking the material to the moment of delivery to the microbiological laboratory does not exceed 6 hours, a sterile tightly closed tube with 0.5-1 ml of phosphate-salt buffer is used.
If the delivery will be carried out within 6-48 hours, commercial transport media (e.g. Portagerm pylori, BioMerieux, France) are used as the transport medium. Storage and transportation of samples are carried out at a temperature of +4 ° C in a place protected from light (container).
If long-term storage is necessary (up to 6 months), biopsies can be stored in 20-25% glycerin broth at -70 °C, but in this case, the viability of H. pylori and the probability of a positive result of bacteriological examination are reduced.