What can we replace blood with?

What can we replace blood with?
What can we replace blood with?

Blood transfusion has saved the lives of millions of people. Still, to transfuse blood is harmful. What's more, it's life-threatening. And no solution to replace the red liquid flowing through our blood vessels has yet been discovered. However, doctors can save a patient's life even when he has lost 70 percent of his blood.

The multi-stage checks that blood donated by donors goes through can reduce the danger and isolate that which contains the viruses of AIDS, hepatitis and other known diseases. But no examination can save you from foreign bodies, to which the body will rebel in the first hours after the transfusion."Today, no one is treated with a blood transfusion. Only savages can do this," say biologists. Blood contains foreign proteins, leading to immunocompatibility problems.

For almost a hundred years, the crude scheme operated according to which blood transfusion was done according to the blood group. When this is done once, the body tolerates the infusion of blood too easily. However, multiple transfusions lead to severe consequences.


Blood is not transfused, but it cannot be done without it. But now the path from the donor to the patient requires much more time and passes through laboratories. In them, the blood is not only checked for viruses, but also divided into components so that a quarter can merge with all the most harmful cells. Objectively speaking, all components of blood cause a negative reaction, but when it is used in parts, this reaction is weaker than if the blood is used in its entirety.

The strategy of today's medicine is to leave only the most valuable - plasma, erythrocytes and platelets. If necessary, they are used. But it is better not to lean on these valuable components of human blood. If possible, it is better to use simple and cheap substitutes.

In human history, there has never been a single solution that completely mimics all the properties of blood. So a blood substitute in the full sense of the word does not yet exist. And it is not even known whether it will be created in the foreseeable future. And considering that today even real blood is considered harmful, it would be strange to seek to replace it. Therefore, now it is better to talk not about a blood substitute, but about an analysis of the patient's condition and the possibility of normalizing the disorders. Doctors solve problems as they arise. Therefore, they also need different solutions.

When a person loses a lot of blood, the first fatal danger is a drop in blood pressure. There is so little fluid left in the vessels that the heart is unable to move it. Fluid loss can be replaced with normal saline, harmlessly replacing up to 30 percent of the blood. This will normalize the pressure and will work for two hours.

Then edema is formed caused by the saline solution. But if the simplest substances are added to it, such as, for example, ordinary household starch, but really very well purified and chemically modified, such a solution can replace up to 50 percent of the blood for a longer period. The pressure remains within normal limits and the heart will not stop.


The second important function of blood is to carry oxygen. All the scandals surrounding "blue blood" are related to the modeling of this function of the blood, with attempts to make such a solution that not only fills the circulatory system and allows the heart to work normally, but also will carry oxygen from the lungs to the tissues.

For a long time, this question was approached simply - how many oxygen carriers (erythrocytes) are lost, so many substitutes to restore this function should be given. The principle is drop by drop. Experience shows that it is very difficult to restore this function completely. All blood substitutes in existence today, including "blue blood", cannot do this. Second, so many erythrocytes are not actually needed.

In a critical situation, the person should be poured with a solution from household car, put to bed and quickly taken to the hospital. And there the doctors will decide what to do next. Their competent actions can save the patient's life, even when he has lost 70 percent of his blood. But in such a case, doctors will rather face the problem of blood clotting. Either a thrombus forms or the blood does not clot (hypocoagulation syndrome). The best way to overcome these problems is blood plasma transfusion. After giving birth, some women experience bleeding that cannot be stopped by anything.

Until recently, blood was transfused in such cases, and this is the best way to kill her. The woman loses three liters and is given exactly three liters. And the woman in labor dies. Now, in maternity hospitals, blood plasma is transfused in such emergencies. She fully compensates for the loss, but not all of the blood. With a loss of three liters of blood, 5-6 liters of physiological solution and a minimum of 1.5 liters of donor plasma should be transfused. But under no circumstances should blood be transfused.

Plasma is also indispensable in cases where a person has not lost much blood, but his blood is poisoned with toxins. A typical example in this regard is a person caught in congestion, in which one of his arms is squeezed, and part of the tissues are damaged, and another part, due to impaired blood supply, begins to die and toxins are formed. Many cases have been described where a man stood for three days with his hand pressed while he was taken out of the burial, and was alive and well. And as soon as they take him out, he dies before the eyes of his rescuers. Why?

Because people who are inexperienced have removed the pressure and all accumulated toxins "invade" the body, poison it and kill it. Before releasing the hand, it must be carefully bandaged so that toxins do not enter the body, and then the hand must be released from the squeeze. In no case should it be done in the reverse order. Despite the impressive successes in the application of blood plasma, it also carries a danger. It may contain undetected or even unknown viruses, may contain many proteins and other substances that are foreign to the recipient's body.


The correct application of the already existing means, the separate use of blood components completely solves the problems associated with large blood losses. But scientists are still working on new blood substitutes to protect people from these dangers that no one knows about yet. When red blood cells are transfused, regardless of all checks, there is still a small risk that the patient will be infected with HIV, hepatitis or hundreds of other viral diseases that are transmitted through blood. But nobody talks or writes about the main, the main risk - we don't know all the diseases, all the dangerous viruses and bacteria. By transfusing a patient with any blood component, we risk infecting them with a disease that we have only heard of because no tests are done for it.

Every year, viruses that were previously thought to be harmless are discovered to be dangerous, such as cytomegalovirus, Epstein-Barr virus, herpes, and others. New viruses are also emerging, such as the Nile virus, which seems to have been unknown before. However, it has now been established that he was known, but in a different modification. The same can happen with many other viruses, new ones are discovered every year. So one of the tasks of scientists is to get rid of the need to take blood from donors and transfuse parts of it in an unprocessed form.

For now, we have moved on from blood as a whole to its components. Medicines must be made which are either derived from blood components or artificially synthesized. For example, plasma contains thousands of different substances (both useful and harmful), including viruses. If these thousands of substances are separated into separate molecules, to separate the proteins of albumin, the proteins responsible for blood clotting, etc., so that no virus gets into it (and this can happen), then the divided into such parts of the plasma will be turned into medicine and sold in pharmacies. This same protein can be made artificially using genetic engineering techniques. The patient will receive exactly the same protein found in the blood of a he althy person.

Only that it will have been obtained in a laboratory, not taken from the person. Scientists are working in this direction. Only a detailed interpretation will show what is needed: whether the tissues are supplied with oxygen, whether blood clotting is restored, whether there is any damage to its transport function. And the restoration of this separate function will be done by the medicine. The clinical trials now underway will not abolish the collection of blood for processing. However, the ultimate goal of scientists is to reduce the need for donors to zero.


The unhe althy interest in blood substitutes gave rise to scandals surrounding perftoran and its derivatives - "blue blood". Perftoran is a very special preparation that is not a complete substitute for blood. First, it replaces not the blood as a whole, but only the erythrocytes. Second, it partially replaces erythrocytes, but is much weaker and does not carry as much oxygen as they do. Thirdly, it does not interfere with other units at all, does not replace the functions of plasma, does not affect blood clotting. It restores the blood volume to the same extent as the physiological solution, since it is made on the same basis.

The opponents of perftoran seem to be right in claiming that it is a bad detergent. But this is not so. Perftoran, as well as other perftoranes, are excellent preparations for organ preservation during transplantation and in the treatment of a number of diseases when some organs are blocked.

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