To make a diagnosis, the doctor usually prescribes a variety of tests to help determine the course of the disease. Blood, urine, mucus or other products of human vital activity are exposed to research.
Blood chemistry
A blood test is performed for almost every disease, because any changes in the composition of the blood can facilitate the diagnosis. It is carried out even if the patient does not show any complaints to his health. That is why, if you really care about yourself, contact your doctor so that he periodically sends you to this study. This is especially true for those who have some problems with the heart, liver and kidneys.
What is KFK?
KFK - what is it? Analysis for CPK is one of the components of the general biochemical analysis of blood and is designed to determine the amount of creatine phosphokinase. This substance, as a rule, is found in some muscles, in particular, in skeletal muscles and the heart.
Creatine kinase is a substance that creates another substance called creatine phosphate from creatine and ATP. This compound is consumed with increased physical activity of the body. In addition to skeletal muscles and the heart, it is located in the cells of the brain, lungs and thyroid gland.
When do CPK readings rise and fall?
If the muscle fibers are damaged, CPK leaves the cells, and its content in the blood increases significantly. That is why laboratory tests to determine the level of CPK in the blood are reliable with an accuracy of about 100%. They allow you to diagnose myocardial infarction. After 2-4 hours after the attack, the analysis will show that CPK is increased, but this figure quickly returns to normal.
In addition, an increase in CPK can be observed with physical injuries of muscles, their crushing and disease, as well as after consuming a significant amount of alcoholic beverages and abuse of sleeping pills.
A decrease in this indicator is not observed in a laboratory study.
Features of the analysis
KFK analysis - what is it and how is the procedure carried out? To study blood for this parameter, the traditional method is used. It consists in the following: from a vein of the forearm (namely, from the upper third of the forearm), a specialist takes a certain amount of blood. After that, the collected blood is sent to the laboratory, where the study is conducted.
Before passing this analysis, the patient is preferably not to eat. So, the result will be more informative and accurate.
To determine the level of CPK, a blood test is performed by photometry. It consists in a molecular absorption spectral study. The techniques included in this examination are based on the absorption of electromagnetic radiation, which occurs in a selective manner. The absorption is carried out by the molecules of that component, the level of which is checked in the visible, infrared, and also ultraviolet parts of the spectrum. Compounds of CPK with the reagent can also be absorbed.
For research, a special apparatus is used - KFK-photocolorimeter.
Indications and results
Indications for analysis are:
- early diagnosis of myocardial infarction (analysis is required in the next 2-4 hours);
- differential diagnosis of myocardial infarction, when this attack is combined with a mild or without complications angina pectoris.
In addition, this analysis is prescribed to all patients who are on treatment for any heart disease in order to exclude the fact of a heart attack. It is knowledge of the level of CPK (that it is, described above) that will help specialists determine the state of the heart. The buildup of this substance in the blood can signal possible heart problems. If this phenomenon is permanent, then the doctor in most cases decides on preventive treatment, which will stop the development of the disease in the future.
Blood CPK (what this can be found at the beginning of the article) is elevated in the following cases:
- myocardial infarction (increased value is diagnosed in the first 2-4 hours, the maximum is reached in a day; after 3-6 days the value decreases, but normalization does not occur);
- muscle dystrophy;
- Reye's syndrome (acute hepatic encephalopathy);
- shock state;
- various poisonings, in particular, alcohol and sleeping pills;
- myocardial infectious lesions.
A reduced level of blood CPK (which is described above) is observed with a decrease in muscle mass, a sedentary lifestyle, and also acts as an indirect sign of the development of thyrotoxicosis (intoxication with thyroid hormones that are produced by the thyroid gland).
CPK level. Norm
In order to adequately assess the ratio of concentration and total activity of CPK, use the calculated relative index. Its formula is as follows:
RI (calculated index) = KFK-MV (μg / l) / total. KFK (Unit / L) * 100
The indicator is calculated as a percentage.
KFK-norm is expressed by the following values:
- <24 U / L –KFK-MV;
- <6% of total CPK activity;
- laboratory norm - 10-110 IU;
- in SI units - 0.60 - 66 mmol / l.
Information that relates to the reference values (norms) of these indicators, and included in the analysis of indicators in different laboratories may vary. However, the difference between the norms is insignificant, and the disease is diagnosed anyway.
How to prepare for blood donation for KFK analysis?
In order for the results to not be false positive, it is recommended to donate blood on an empty stomach. Drinking pure water without impurities is allowed. After eating, before giving blood to determine the level of CPK (what it is, described in detail above), at least 8 hours should pass, and the more, the better. If you are taking any medications, taking a test is not recommended. This should be done before taking the drugs or two weeks after the end. If you can’t stop taking medications in any way, then the laboratory assistant must indicate all the drugs that are currently being systematically taken by the patient, as well as their dosage.
Another important point that needs to be considered before donating blood is sports. Before direct analysis, it is highly recommended not only to perform active physical exercises, but also to experience stressful situations and drink alcohol even in small doses. In addition, do not rush to donate blood to determine the level of CPK immediately after fluorography, x-ray (even if you took a picture of a tooth or finger), ultrasound, various physiotherapeutic procedures or rectal examinations.
What can affect the level of CPK?
There are a number of factors that can affect the results of a study of blood CPK, and lead to their distortion:
- high physical activity;
- taking medications by injection;
- chilez tests;
- taking a number of medications;
- hemolysis.
An elevated level of CPK, which is determined by laboratory research, may indicate changes in the body that are associated with myocardial infarction, rhabdomyliosis, muscle dystrophy, myotis, excessive physical exertion, as well as operations carried out of varying complexity.
If there is a decrease in the level of this indicator, then this does not have any diagnostic value.