What role does blood play in the human body? How to ensure blood safety? What is the blood warning mechanism? Listen to what Gan Jia, director of the Department of Blood Transfusion at Peking Union Medical College Hospital, said——
About the author: Gan Jia
Director of the Department of Blood Transfusion, Peking Union Medical College Hospital.
Function of human blood
Blood, like the rivers and lakes in nature, plays an important role in everyone's life system, often called the "river of life". Blood has many functions, the most important of which is transport. Blood can transport oxygen acquired by the lungs throughout the body, or it can transport carbon dioxide produced by cells to the lungs and excrete them; it can transport nutrients to the tissue cells of various organs, it can transport hormones to the corresponding cells, and it can also transport metabolites to the kidneys and excrete them out of the body. In addition, blood also has the functions of maintaining the acid-base balance of the human body, participating in the body's hemostasis, resisting pathogenic microorganisms and maintaining normal body temperature.
Due to the limitations of medical technology, there is no drug or treatment that can completely replace blood transfusion treatment, so in medical treatment, blood donated by healthy volunteers is still needed.
Donate blood for free
Unpaid blood donation is divided into two forms: donating whole blood and donating component blood. Whole blood can be separated into red blood cells, plasma, etc., and component blood is also used in the treatment of different diseases in the clinic. From the perspective of clinical blood, the early clinical transfusion treatment is mainly based on whole blood. After the whole blood is divided into different components, it is conducive to the preservation of each component, improves the utilization, plays different roles, and improves the treatment effect. With the improvement of technical means such as preservation, isolation and preparation, people gradually realize that different blood components in whole blood are under different preservation conditions, and the treatment effect will also be affected if they are preserved in the form of whole blood.
Component transfusions are now being promoted as the main transfusion treatment. Usually, with the exception of whole blood transfusion in case of trauma, postpartum blood loss, or major bleeding during surgery, it is safer and more effective to use component blood in most clinical situations. For example, in patients with anemia, only the infusion of red blood cell components can improve the level of tissue oxygenation, improve the symptoms of anemia, and reduce the risk of adverse reactions caused by the infusion of other unwanted blood components to the patient.
When is a blood transfusion required? How to ensure the safety of blood transfusions?
Blood transfusion therapy is a very important clinical treatment method, mainly used in trauma, obstetric perinatal hemorrhage and surgical bleeding, other bleeding disorders and so on. In addition, transfusion therapy is also used in patients with hematologic diseases and bone marrow suppression after tumor radiotherapy and chemotherapy.
Blood transfusion safety is actually a relatively large concept that covers a lot of content. The first is safe blood, which comes from unpaid blood donations. The emphasis on unpaid blood donation is because altruistic-driven unpaid donation greatly reduces the risk of transfusion-borne diseases. Of course, safe blood also includes a complete set of quality control and operation systems of blood collection and supply agencies. Through these methods, means, and screening of donors, safe and appropriate blood can be selected for clinical use.
The second is patient identification. The matching of information between the patient undergoing the transfusion treatment, the specimen, and the blood component to be transfused is checked before transfusion, and the transfusion compatibility test results are confirmed. This is the most likely link to endanger the safety of patients' lives, in short, to "transfuse the right blood to the right patient", and patient identification runs through the entire process of blood transfusion.
Then there is the application of immunohematology techniques. We know that allogeneic blood transfusion will occur immune recognition and response process, the blood components of the allogeneic body will trigger a series of adverse reactions, so before the transfusion we must strictly carry out immune hematology testing, first blood group detection, then red blood cell antibody screening test, and then cross-matching before transfusion. After a rigorous testing process, we can give the blood that passes the test to the patient.
In addition, before transfusion, doctors should evaluate whether the patient has transfusion indications and alternative blood transfusion treatment options, eliminate unnecessary blood transfusions, take timely and effective medical intervention for patients who must undergo blood transfusion treatment, and doctors will also reduce the need for allogeneic blood transfusion as much as possible through patient blood management methods to reduce the risk of blood transfusion. In the process of blood transfusion, medical staff should observe whether the patient has adverse reactions, and whether the basic vital signs have changed, etc., if there is an adverse reaction, the medical staff will deal with it in time, and analyze the causes and adjust the blood transfusion strategy.
Therefore, from safe blood, to identification, patient blood management, laboratory testing in the later stage, monitoring during treatment, and control of blood transfusion indications, a series of key elements of blood transfusion safety are constituted.
Of course, in daily life, everyone should pay attention to the problem of transmitting diseases through blood transfusions. Many infectious diseases can be transmitted through blood transfusions, such as hepatitis B, hepatitis C, AIDS and so on. In order to avoid blood transfusion of diseases, in the medical process, in addition to the need to receive blood transfusion treatment, should try to avoid allogeneic blood transfusions; secondly, the spread of some pathogenic microorganisms will also occur through unclean acupuncture process, so acupuncture, injection treatment and tattoos, ear piercings and other must choose a regular institution.
In addition, these pathogenic microorganisms may also be transmitted through sexual contact and body fluids, and unclean sexual behavior should be avoided.
Maintaining healthy lifestyle habits is the foundation. In addition to a reasonable diet, adequate rest and proper exercise are also required. Only by developing a healthy lifestyle and having a healthy body can we have healthy blood.
Will blood transfusions between relatives work better?
We do not advocate and encourage blood transfusions between relatives, especially between first-degree blood relatives. Because blood transfusions are performed between relatives, the risk of transfusion-borne diseases is no less than that of unrelated blood donors. Second, blood transfusions between close relatives may increase the risk of transfusion-associated graft-versus-host disease (TA-GVHD). How to understand this risk? In the case of relatively weak immune surveillance function of the patient, receiving blood with a relatively high degree of match with his own leukocyte antigen system, the patient's immune system failed to recognize the lymphocytes that cleared the body in time, and these lymphocytes will activate in the patient's body, and then attack the patient's cells, tissues, and organs, resulting in the occurrence of blood transfusion-related grafts against host disease.
From the current clinical report, the overall incidence rate is not high, but the mortality rate is very high, so blood transfusions between close relatives are not recommended.
If, due to special circumstances, a blood transfusion between close relatives is really necessary, and the blood component containing blood cells needs to be irradiated before transfusion, which can greatly reduce the risk of transfusion-related graft-versus-host disease.
Source/Chinese family report official micro
Image/from the web
Editor/Hong Chengwei
Editor-in-Chief/Chen Mingyan
Producer/Wu Peixin