How to properly collect urine for testing

This is an automatically translated article.

The article was professionally consulted with MSc Do Thi Hoang Ha - Doctor of Biochemistry, Laboratory Department - Vinmec Hai Phong International General Hospital.
Urine test is one of the important tests, helping you to recognize the signs of dangerous and latent diseases in the body because urine is the most important secretion, which contains most of the substances. body waste. Regular urine test is a simple and necessary job to know your health status. Although this is a test that is quite familiar to many people, not everyone knows how to properly collect urine for the test to be performed most accurately.

1. How much urine is enough?

Urine samples are required to be clean and fresh. This urine sample allows routine tests such as rapid urinalysis with dipsticks – this test allows to check for the presence of proteinuria or other abnormalities such as pink white blood cells, white blood cells, urinary casts, phosphate crystals, calcium oxalate... appear in the urine. When a specialist disease is suspected, the patient may be asked to obtain a urine sample with specific procedures to meet the necessary testing needs.
Depending on the individual sampling procedure, the urine sample will be required to prepare differently, but usually, the external genitals must be cleaned and the first part of the urine removed (about 100-200ml or later). a few seconds to urinate) , then collect urine midstream and store it in a sterile sample vial. Urine samples are usually taken in the morning.

2. Do you have to fast to collect urine?

This is an issue a lot of people want to know so that they can be well prepared right at home. It is best to fast and fast at the same time to get the most accurate test results.
Do not eat or drink before the test because the urine test only gives accurate results when the patient fasts 4-6 hours before the urine test or does not eat breakfast after waking up. You should not eat a lot of foods that can cause urine to change color such as: beets, raspberries, carrots or rhubarb. Some drugs also change the color of urine such as anticoagulants, metronidazole, sulfonamide, ferrous sulfate..
Not only fasting, test takers also need to avoid using stimulants such as tobacco, coffee... for 12 hours before taking urine for accurate diagnosis.

3. Collect urine for testing during menstruation

When you are in your menstrual period, if you do a urine test, it is likely that the results will not be accurate, because the urine sample taken may contain menstrual blood, when performing the analysis, the results will be affected. enjoy. People who are in their menstrual cycle or near the beginning or end of their period should tell their doctor to wait until their next test.
In addition, the use of many drugs, including dietary supplements, will affect the results of urine tests. Some medications that can affect urine test results (causing false positives or false negatives for certain components in the urine) include vitamin B, ascorbic acid, phenazopyridine (Pyridium), rifampin, phenytoin (Dilantin). ... Tell your doctor if you are taking diuretics, as they can affect the accuracy of test results, especially glucose in the urine. Therefore, before doing the test, the doctor may ask the patient to stop taking the drug for a while to ensure the test is accurate.

4. How to collect urine?

There are two ways to collect urine: the patient can urinate on his own and through the bladder.
4.1 Urine collection technique for self-urinating patients The doctor may order a urine collection test in 24 hours or only collect a quantity of about 20ml at a time.
Specifically, the one-time urine collection procedure is as follows:
Instruct the patient to clean the external genitalia and then urinate, the first and last urine in a potty, the middle part of the yard into a potty; The nurse put on gloves to put urine in the middle of the yard into the measuring tube and put urine from the measuring tube into the test tube about 20ml, cover the test tube; Bring specimens and test papers to the laboratory; Arrange and dispose of tools according to regulations. Procedure for collecting 24-hour urine:
In the case of 24-hour urine collection, if not refrigerated, a preservative must be used: 1% solution of hydrochloric acid (8-10ml), formol or phenol for one drop corresponding to 30ml urine, 1% thymol in alcohol for 1ml corresponds to 100ml of urine, then gradually increase according to the patient's urine output; The preserved solution is evenly coated and stored in the patient's 24-hour urine storage tank/can. Usually a 24-hour urine sample is recommended to be taken the morning before the day of examination. The patient is instructed to clean before each urination, discard the first urination, start from the second time. Instruct the patient to collect urine when defecating, cover the potty after each urination and keep cool; Patients are instructed to drink water as usual. After the last urinating the next morning (ending at the time of sampling the previous day), the nurse measures and records the 24-hour urine output on the monitoring sheet; Shake well, collect the required amount of urine into the test tube, send the urine and test paper with the patient's 24-hour urine volume to the laboratory.

4.2 The technique of collecting urine through the bladder Collecting urine through the bladder catheter in the following cases:
Patient with urinary incontinence; Children are unable to collect urine on their own; Women who are menstruating; Practice technique:
The patient lies on his back comfortably on the bed, plastic is spread under the patient's buttock. Cover with a shawl, remove the patient's pants, turn the gown diagonally to cover the legs and genitals, legs propped up, thighs slightly apart; Place trays or packages of sterile instruments, bags containing soiled items between the patient's legs; Open the sterile tray, spread with holes to expose the genitals; Put gauze and erect the penis to expose the foreskin (for men), put gauze on the pubic bone (for women), disinfect the genitals with betadine solution or red medicine. With male antiseptic mouth flute, foreskin; with female antiseptic large lips small lips, urethral openings; Lubricate the tip of the catheter, clamp the end of the catheter with a Kocher clamp, and place the sterile bean tray in the middle of the thigh; Gently insert the catheter tip into the patient's urethra about 4-5cm for female patients, about 15-20cm for male patients; Open the Kocher clamp. When you see urine out, remove the first part of urine and take the next part of urine into the test tube about 20ml. When the urine runs out, bend the tip of the catheter and pull out the catheter; Dry the genitals, remove the holes, remove the plastic, put on the patient's pants, help the patient lie down comfortably, remove the scarf, cover the patient with a blanket; Send specimens and test papers to the laboratory.

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