Rh positive is the most common blood group. Rh negative is less common, and certain precautions must be taken with Rh negative women when pregnant. If their partner is Rh positive, there is a possibility that the baby will also be Rh positive, which may lead to complications during pregnancy.
This occurs if the blood of the mother and child come into contact. This is usually not a problem in a first pregnancy, but it can be a problem in later pregnancies, as antibodies could penetrate the placenta and attack the red blood cells of a future Rh-positive baby. This could cause anaemia in the foetus that could kill it. At the first prenatal consultation, the doctor will request a blood group and Rh factor test for the mother.
If you are Rh negative, you will probably have an antibody test in the first trimester to detect possible Rh positive antibodies and, if necessary, take further action with anti-D gamma globulin injections. Here, blood plasma without cells is mixed with type A or type B blood:. To establish whether the blood is Rh positive or negative , we look at whether or not the blood has proteins on the cell surface. If there are proteins on the cell surface, it would be Rh positive and if not, it would be Rh negative.
Blood groups are hereditary. They have a Mendelian pattern, in other words, they are the product of a single gene. The first two, A and B, are codominant, in other words, they dominate equally. However, allele O is recessive. The different combinations among these three alleles generate the different blood groups. ABO incompatibility. Due to modern testing techniques, this problem is very rare.
The different blood types are: Type A Type B Type AB Type O People who have one blood type may form proteins antibodies that cause their immune system to react against one or more of the other blood types.
People with type B blood will react against type A or type AB blood. The following are symptoms of ABO incompatible transfusion reactions : Low back pain Blood in urine Chills Feeling of "impending doom" Fever Nausea and vomiting Shortness of breath Increased heart rate Pain at infusion site Chest pain Dizziness Bronchospasm spasm of the muscles lining the lung; causes cough Yellow skin and whites of the eyes jaundice Acute kidney failure Low blood pressure Disseminated intravascular coagulation DIC.
Exams and Tests. The health care provider will perform a physical exam. Blood tests will usually show: The bilirubin level is high The complete blood count CBC shows damage to red blood cells or anemia The recipient's and donor's blood are not compatible Elevated lactate dehydrogenase LDH Elevated blood urea nitrogen BUN and creatinine ; in case of renal injury Prolonged prothrombin time or partial thromboplastin time findings of DIC Positive direct antiglobulin test DAT Urine tests show the presence of hemoglobin due to breakdown of red blood cells.
In case of any reaction, transfusion should be stopped immediately. Treatment may also include: Medicines used to treat allergic reactions antihistamines Medicines used to treat swelling and allergies steroids Fluids given through a vein intravenously Medicines to raise blood pressure if it drops too low. Outlook Prognosis. Possible Complications.
Learn more: Transfusion therapy ». Type B blood cells carry B antigens. That means people with type A blood create antibodies against B antigens. In an ABO incompatibility reaction, your immune system attacks the new blood cells and destroys them.
If you have type AB blood, you have both A and B antigens. However, you can only donate blood to other people who have type AB blood. You can give your blood to anyone without triggering their immune system, but you can only receive type O blood. Before a blood transfusion, your doctor will test your blood to determine your blood type.
A small sample will be crossmatched with some of your donated blood. The two samples of blood are then mixed and watched for a reaction. Human error is the most likely cause of an ABO incompatibility reaction.
If your transfusion uses the wrong blood type, it could be the result of mislabeled blood, incorrectly completed forms, or a failure to check donated blood before the transfusion.
These may include:. Medical staff will stop the blood transfusion if they suspect you might be having an incompatibility reaction.
Learn more: Transfusion reactions ». More specifically, veins may appear blue in some people from the way subcutaneous fat absorbs low-frequency light. This permits only high frequency blue and violet wavelengths to penetrate through the skin to the vein, with the other wavelengths getting filtered off from the pigmentation of your skin.
A similar light diffusion process is happening when we see people who are suffocating and have purple lips and fingertips. In this case, the blood is so oxygen deprived that it turns an extremely dark shade of red. When the light diffuses through the skin of the lips or through your fingernails, it then often ends up looking very dark blue or purple. In reality of course, blood is various shades of red, with the red color primarily coming from the hemoglobin, which contains four heme groups.
This is due to a chemical found in the amoebocytes of its blood. When this is exposed to a potentially dangerous foreign bacterium, it will immediately coagulate around the threat, rendering it harmless without actually destroying it. This effect is amazingly useful for detecting bacterial contamination in things like medicines and vaccines, or on medical equipment like needles, pacemakers, and numerous other items that are required to be sterile.
In fact, no drug on the market today can be certified by the FDA unless it has been tested using this exact method known as the Limulus amebocyte lysate test, in homage to the species of the crab- Limulus polyphemus.
The blood cells are then separated using centrifugation. Next, the isolated cells are placed in distilled water where they will eventually burst, releasing the valuable chemical inside. After being purified, it is then freeze-dried and stored to be used for testing. Even with the relatively good survival rates, all of this may sound harsh. But there is one type of animal besides humans that, at the least, is glad this property of horseshoe crab blood was discovered in by Dr.
0コメント