In vitro diagnostic reagent science knowledge answer (V)

41. What problems can laboratory examination help you understand?

Answer: The purpose of using in vitro diagnostic reagents for laboratory examination is mainly to assist clinicians in diagnosing the disease, observing the curative effect and adjusting the treatment plan.

Some test items have positive significance for the diagnosis of a certain disease. If Mycobacterium tuberculosis is detected in the sputum, the patient can be diagnosed with open tuberculosis. However, many laboratory tests must be combined with clinical symptoms, signs and other comprehensive analysis of the examination to confirm the diagnosis.

If you have been diagnosed with a certain disease, changes in specific laboratory results are of great value in judging the efficacy and changes in the disease. For example, anemia patients after treatment, the red blood cell count and hemoglobin gradually increased and returned to normal, indicating that the treatment is effective, and is an important indicator to judge whether the cure. That is, a return to normal in laboratory tests is usually an indication of improvement. However, it must be noted that in the course of the disease, clinically significant laboratory indicators are not necessarily synchronized with changes in the disease.

Therefore, if you see changes in some indicators of the laboratory test form, you must consult a doctor.

42. What are the precautions for specimen collection when doing laboratory tests?

Answer: When using in vitro diagnostic reagents for laboratory tests, incorrect collection of specimens such as hematuria and stool will directly affect the accuracy of the test results.

The most common cases of incorrect specimen collection are:

A. blood collection is not on an empty stomach (in general, blood collection for laboratory tests requires about 12 hours on an empty stomach, and the results are the most stable at this time, except for blood collection after meals);

B. hemolysis of blood samples and severe lipemia will affect many indexes;

c. After antibiotics are used, specimens are collected for bacterial culture;

D. no pathological specimens or specimens mixed with other human components (such as sputum specimens mixed with saliva, etc.);

e. collection of specimens after taking certain drugs, etc.

Specimens collected in the above situations may lead to incorrect test results and inaccurate judgment. Should comply with the relevant requirements of the specimen, in order to get the correct test results.

Before doing the test, the doctor or nurse will remind the relevant precautions, these reminders must be followed. After obtaining the test report, ask a doctor to analyze the test results and do not make your own claims.

43. What should I pay attention to when buying a blood glucose meter for self-testing?

Answer: Self-testing blood glucose meters are more common, because the monitoring of blood glucose changes is an important part of diabetes diagnosis and treatment. It is best to consult a doctor or professional before buying. It is necessary to make clear whether the purpose of the purchase matches the function of the blood glucose meter. It is necessary to purchase qualified products in a regular pharmacy or medical device business place, and purchase them in combination with their own needs and conditions.

The blood glucose meter machine and the test paper are matched, and the matching blood glucose test paper must be used.

What needs to be clear is that the detection accuracy of the self-test blood glucose meter is not as good as the classic test in the hospital, and there is a deviation of ± 20% according to the national standard. It is only used for the monitoring of blood glucose level and cannot be used as the basis for the diagnosis of diabetes. Even if you often use a self-test blood glucose meter to monitor, you still need to go to the hospital regularly to retest to accurately understand the real blood glucose control status.

44. What should be paid attention to in the preservation and use of blood glucose test paper for self-testing?

Answer: When purchasing blood glucose test strips for self-testing, check the integrity and expiration date of the product packaging. Do not use expired or invalid test strips. Make sure that the code displayed by the blood glucose meter is the same as the code of the test strip.

Blood glucose test paper should be stored in a dry and cool place, avoid direct sunlight and high temperature (not higher than 30 ℃), blood glucose test paper should not be refrigerated, put in the refrigerator will make the test paper damp; should be stored in the original blood glucose test paper bottle, do not put the test paper in other places.

Please make sure that your hands are clean when touching the blood glucose test paper. If the blood glucose test paper bottle is damaged and left open for a long time, do not use it. Do not bend, cut or change the shape of the blood glucose test paper in any way.

Blood glucose test strips are for single use only. Under normal circumstances, blood glucose test paper can not be stored for a long time after opening the bottle, to check the product instructions, according to the instructions to guide the use of the end.

45, self-test blood glucose meter each test results are different, is there a problem with the instrument?

Answer: Like normal people, the blood sugar level of diabetic patients is not only affected by physical condition and changes in their own hormones, but also affected by mood, diet, exercise and drugs. The blood sugar level is constantly changing during the day, so each time it is measured. The blood sugar value will be different, which is normal.

If you have any questions about the self-test results, you can continuously test 2-3 times at the same time. If the test results differ greatly, review and check whether the test steps are correct and whether the test paper is expired or invalid. If still not at ease, should go to the hospital to consult medical staff.

When the blood glucose level is found to be particularly unstable at home, the guidance of medical personnel should be sought in time.

46. Should vitamin C be stopped before blood sugar test?

It is often done for diabetic patients to test blood sugar, because only by accurately measuring the blood sugar content in the body can they judge the changes in their condition, so as to formulate a reasonable treatment plan and properly regulate diet control. However, patients who need to take vitamin C therapy should stop using VC before testing, otherwise they will get wrong test results and affect treatment.

Vitamin C is a strong reducing agent, it is easy to react with the chemical composition of blood sugar test paper, interfere with the accuracy of the test results. If a diabetic patient is given an intravenous drip of VC, the results of the blood glucose test will be more inaccurate. Therefore, vitamin C should be stopped 2-3 days before blood sugar testing. In the same way, it is best not to eat vegetables rich in vitamin C (such as dark vegetables such as leeks, spinach and persimmon peppers or wild mustard) and fruits (such as grapefruit, citrus, kiwi fruit, jujube, etc.) 1-2 days before the test.

47. What are the misunderstandings in the application of self-testing blood glucose meters?

Answer: The use error of the blood glucose meter for self-test will artificially affect the accuracy of the test results. There are three common ways to make mistakes:

(1) When measuring blood sugar, because it was not deep and the amount of bleeding was small, it was squeezed hard. As a result, the tissue fluid was squeezed out, which affected the accuracy of the measurement. In addition, the blood site (such as fingers) must have a certain temperature. If the temperature is very low, the blood vessels are easy to contract, resulting in too little bleeding, and the test results will be inaccurate.

(2) It is recommended to use alcohol for disinfection during measurement. If iodine is used, it will lead to deviation in the test results. When disinfecting with alcohol, you should also wait for the alcohol to completely evaporate before testing, otherwise the alcohol will dilute the blood and the results will not be allowed.

(3) Pay attention to the airtight dry preservation and expiration period of the test paper. Some test strips are naked in a whole box. After taking out a piece of test paper, the box should be closed immediately to keep the test paper dry and prevent oxidation reaction.

48, the use of ovulation test paper, should understand what the basic truth?

Answer: A. Ovulation test paper detects the peak level of luteinizing hormone (LH) in human urine samples. It is used to detect the "safe period" during ovulation and female menstrual cycle. It must be used under the guidance of a doctor.

B. ovulation test paper is not suitable for pregnant women. if LH peak phenomenon occurs for several days, pregnancy should be detected first.

C. general commonly used drugs (such as cold medicine, antibiotics, painkillers, etc.) have not been reported to affect the accuracy of the test, but if the injection or taking drugs containing HCG and other pregnancy aids will affect the test results.

d. When used for contraception, when the test line is slightly shallower than the control line during the test, contraceptive measures should be taken during the same room. Women are sometimes affected by the environment, mood and fatigue, and may ovulate in advance.

e. The following conditions may affect the test results: menopause, taking hormones, steroids and contraceptives, or suffering from polycystic ovary syndrome, hyperthyroidism and some endocrine diseases.

f. The detection of ovulation test strips is not absolutely accurate. There are a large number of clinical cases of missed ovulation and LH peak. Many women can only detect weak positive (indicating that ovulation is about to occur or ovulation has occurred) and cannot detect strong positive (indicating that ovulation is occurring), which does not mean that ovulation has not occurred. If you have any questions during use, it is recommended to consult a doctor early.

49. What do you think of the test results of early pregnancy test paper?

Answer: Pregnant women's urine will contain human chorionic gonadotropin (HCG). Early pregnancy test strips help determine whether they are pregnant by detecting the concentration of HCG in women's urine.

Early pregnancy test paper is used to detect women's early pregnancy diagnostic supplies, divided into strip type, pen type and card type.

In the case of effective detection, there are two test results of the test paper: in the case of color band in the test paper control area, there is no color band in the test area, indicating negative, indicating that no pregnancy; In the test paper control area and the detection area, there are obvious color bands, indicating positive, indicating that pregnant. The final judgment needs to go to the hospital in time for diagnosis.

What needs to be clear is that the early pregnancy test paper can only be used as a preliminary screening test, and you must not trust it too much, because there will be false positives or false negatives. To be clear whether pregnant, or should go to the hospital.

50. What are the main reasons for the false detection of early pregnancy test paper?

A: The quality, preservation and testing methods of such test strips affect the accuracy of the test results. The main mismeasurements are:

(1) The detection time should not be too early. It is best to do early pregnancy test paper test when menstruation is delayed for two weeks. If the test result is negative, menstruation is still coming after 1 week and should be done again.
(2) Urine is diluted. If you drink too much water so that the urine dilution may lead to false negative results.
(3) Testing in the morning and evening may have an impact on the results. The human chorionic gonadotropin (HCG) value in the urine in the morning is high, so the product manual of the test paper recommends testing when getting up in the morning, but this is not absolute.
(4) Pay attention to the length of urine immersion test paper during detection. Urine immersion test strips that are too long may make the test results difficult to judge.
(5) If you have had a pregnancy recently, do not judge whether you are pregnant by the test results. Because HCG can continue to be positive for a long time after termination of pregnancy (after childbirth, spontaneous abortion and induced abortion).
(6) Some diseases and drugs may cause false positive results. Such as blood in the urine, or taking some fertility drugs, or suffering from hydatidiform mole, choriocarcinoma, bronchial cancer and kidney cancer, HCG content in the urine may continue to be positive.
(7) the use of expired test paper must be misjudged. Pay attention to the production date and validity period when using.
(8) After opening the aluminum-plastic bag, do not place the test paper in the air for too long to avoid moisture and failure.
(9) The test paper is a disposable product and cannot be reused.