Blood transfusion is an indispensable clinical treatment measure. However, due to the complex composition of whole blood and more antigenic components; and once whole blood leaves the blood circulation, except for red blood cells, the remaining components are rapidly inactivated in a relatively short period of time, so the indications for transfusion should be strictly controlled to avoid adverse reactions.
Component transfusion, which started in the 1960s, is an important development of modern blood transfusion technology. Currently, it has been commonly used in developed countries and has become one of the symbols to measure the development of medical technology; in China, it has also been gradually adopted in hospitals in major cities since 1978. The advantages of component blood transfusion are economic, economical, multi-use of one blood, so that one person donates blood, many people benefit; and its products have the characteristics of high purity, high concentration and good efficacy, minimizing the adverse effects of blood transfusion and the spread of diseases.
I. Commonly used blood and component blood
(A) Whole blood The meaning of fresh whole blood varies with the purpose of blood transfusion. If the purpose of transfusion is to correct anemia, red blood cells from any day within the preservation period (21 days-35 days) are available; if the purpose of transfusion is to replenish platelets or granulocytes, whole blood within 12 hours or 8 hours of transfusion is considered fresh. Therefore, whole blood is not whole! The current clinical use of “fresh whole blood” actually contains low concentrations of platelets and granulocytes, which is difficult to meet the needs and has been gradually replaced by component blood.
(B) Component blood
1.Blood cell products
(1) Concentrated red blood cells about 130ml/u. Each u contains 200ml of red blood cells of whole blood and 30ml of plasma. The capacity of oxygen transport is the same as whole blood, but the volume is only half of whole blood, and the anticoagulant is lower than whole blood. Adult transfusion of 1u can increase hemoglobin by 5g/L.
(2) Washing red blood cells About 110ml/u, each u contains 70% of red blood cells (60-70ml) in 200ml of whole blood, 50ml of saline; remove more than 80% of white blood cells, 99% of plasma and potassium, ammonia, lactic acid, anticoagulant and tiny clot, can reduce transfusion reaction and infectious viral hepatitis. It can elevate hemoglobin by 10g/L per 3u.
(3) Semi-plasma blood 180-200ml/u. Each u contains 200ml of red blood cells of whole blood and 100-120ml of plasma and 50ml of ACD preservation solution. Each u can raise hemoglobin by 5g/L.
(4) Highly concentrated red blood cells About 130 ml/u. Each u contains 200 ml of red blood cells from whole blood and an appropriate amount of added fluid (containing glucose, adenine, sucrose or mannitol). Because it contains very little plasma, it is the best choice for improving the efficiency of red blood cells because it has less transfusion reaction.
(5) Red blood cells with less white blood cells About 120 ml/u. Each u is made from 200 ml of whole blood, containing 60-80 ml of red blood cells and 50 ml of saline, removing more than 70%-95% of white blood cells. Each u can raise hemoglobin by 4g/L.
(6) Young red blood cells About 190ml/u. mainly contains reticulocytes and younger red blood cells. Long survival time and strong oxygen carrying capacity after infusion. 1u per infusion.
(7) Concentrated granulocytes: about 190 ml/u. Each u contains 1.5×1010 granulocytes and a few red blood cells, lymphocytes and platelets. Because of more drawbacks, it is rarely used at present.
(8) Concentrated platelets Machine harvesting method 1 unit about 3000ml of whole blood, containing an average of 2.5 × 1011 platelets, mixed with few white blood cells and red blood cells. The platelet count can be increased by 5-10×109/L by transfusing 1.0×1011 platelets per square meter of body surface area. 1u per transfusion for adults, 2u per 10kg body weight for children, once every other day. Note: ABO blood group isotype is required for transfusion; gently shake before transfusion, but avoid shaking sharply to avoid destroying platelets.
2.Plasma products
(1) Fresh frozen plasma is available in 200ml, 100m1 and 50ml per bag. Except platelets, it contains all coagulation factors, similar to fresh whole blood. 200ml of this product contains 60-80g/L plasma protein, 2-4g/L fibrinogen and 0.7-1.0u/ml other coagulation factors.
Caution.
①Isotype or ABO blood group compatibility.
②Thaw in a 37℃ water bath when used, not at room temperature or in tap water to avoid fibrin precipitation.
(2) Ordinary frozen plasma Specifications are the same as fresh frozen plasma. Except for the lack of factor V and VIII, the rest is the same as fresh frozen plasma.
(3) Cold precipitation 20-30ml/bag. If a bag of cold precipitate is prepared from 400ml of fresh whole blood, it contains about 100u of factor VIII and XIII, about 250u of fibrinogen, a large amount of fibrin and vascular hemophilia factor.
Usage.
①Treatment of hemophilia A is calculated on the basis of each bag containing 100u of factor VIII. 10-20u per kilogram of body weight is transfused for mild bleeding, 20-30u per kilogram of body weight for moderate bleeding, and 40-50u per kilogram of body weight for severe bleeding.
②Vascular hemophilia infusion of 1 bag per 10 kg body weight.
③Supplementation of fibrinogen (e.g. postoperative bleeding, severe trauma, DIC, massive burns, liver failure, etc.), 8 sachets per infusion for adults. Melt in a 37°C water bath and inject intravenously at the fastest rate tolerated by the patient. Every 1 time, for more than 3 days.
(4) Factor VIII Concentrate There are 200IU, 300IU and 400IU specifications. To prevent bleeding in patients with hemophilia A, use 10-15IU per kilogram of body weight for mild bleeding, 20-30IU per kilogram of body weight for moderate bleeding, and 40-50IU per kilogram of body weight for severe bleeding, and inject intravenously.
(5) Thrombospondin Complex 200IU/bottle. Used to treat factor II, VII, IX, X deficiency, such as hemophilia B, severe liver disease patients with bleeding.
(6) Albumin Usually has three specifications of 5%, 20% and 25%, 50ml per bottle.
Indications.
(i) Hypovolemic shock.
(ii) Large area burns.
③Cerebral edema.
④Neonatal hyperbilirubinemia.
⑤ acute liver failure.
⑥hypoproteinemia.
(7) Plasma replacement, etc.
(7) Intravenous human blood immunoglobulin: 2g/bottle, 2.5g/bottle, 3g/bottle.
Indications: ①Congenital or acquired humoral immunodeficiency.
②Severe infections that are difficult to be controlled by antibiotics.
③ autoimmune diseases, etc.
3. Plasma substitute
Such as medium-molecule or low-molecule dextrose, which can maintain blood volume and colloid pressure. The former has better colloid effect; the latter can improve microcirculation and regulate water-electrolyte balance.
II. Indications for clinical transfusion and selection of component blood
The main clinical conditions requiring blood transfusion include trauma, obstetrical and gynecological hemorrhage, upper gastrointestinal bleeding, DIC, acute hemolytic anemia, bleeding disorders, burns and so on. Specific indications are as follows.
1, hemorrhagic shock Blood loss greater than 1000ml, the patient sees obvious dizziness, palpitations, oliguria, fine and faint pulse count, blood pressure drops, hemoglobin drops significantly, manifesting as hemorrhagic shock, transfusion of concentrated red blood cells, or whole blood, half plasma blood as appropriate. Note that if the blood loss is less than 400-500ml, blood transfusion is not necessary; if the blood loss is 500-1000ml, the patient sees mild dizziness, palpitation, weakness, pale face, accelerated heartbeat and respiration, and weak pulse, electrolyte solution or plasma substitute can be transfused.
2.Insufficient oxygen carrying capacity Refers to normal blood volume but insufficient oxygen carrying capacity, such as various types of anemia and carbon monoxide poisoning, etc. Patients see shortness of breath, hair clamp, pale face chip, can be transfused with concentrated red blood cells or highly concentrated red blood cells; but immune hemolytic anemia, paroxysmal sleep hemoglobinuria patients should be selected with washed red blood cells or red blood cells with less white blood cells.
3, platelet deficiency If platelets are less than 5×109/L; or platelets are 5-10×109/L and there is obvious skin and mucous membrane bleeding; patients with less than 30-50×109/L platelets before surgery and have bleeding symptoms; or platelets are higher than 30-40×109/L but there is still obvious bleeding, including intracranial and fundus bleeding, platelet concentrates should be transfused until bleeding symptoms However, immune thrombocytopenia or primary thrombocytopenic purpura is not as effective as platelet transfusion.
4, coagulation factor deficiency In patients with hereditary coagulation factor deficiency with hemorrhage, coagulation factor products or fresh frozen plasma, ordinary frozen plasma, prothrombin complex can be transfused as appropriate; in mild hemophilia A and children with hemophilia A under 6 years old, vascular hemophilia, cold precipitation should be transfused; if the plasma contains anti-factor VIII or Ⅸ antibodies, prothrombin complex should be transfused; in patients with severe hemophilia, factor VIII or Ⅸ concentrates; in patients with severe hemophilia, factor VIII or Ⅸ concentrates should be transfused; for bleeding from large burns, severe trauma, major surgery, DIC, and coagulation factor deficiency due to severe liver disease, fresh or plain frozen plasma, cold precipitation, and prothrombin complexes should be transfused.
5.Immune function deficiency Granulocyte transfusion can be considered when granulocyte is less than 0.1-0.5×109/L. In primary or secondary immunodeficiencies, the relative insufficiency of antibodies in severe infections and sepsis, transfusion of intravenous human blood immunoglobulin is possible.
6, plasma protein reduction Patients with hypoproteinemia such as massive burns, cirrhosis, chronic nephritis and intestinal fistula, as well as hemorrhage and major surgery, should be supplemented with 20-25% albumin in order to prevent and control tissue edema, so that the total plasma protein reaches more than 50g/L. Note that plasma transfusion is no longer advocated to supplement plasma protein or volume expansion, antibody supplementation or nutrition, etc.
7.Exclusion of harmful substances, i.e. blood exchange therapy. For the treatment of carbon monoxide, phenol and other chemical poisoning, concentrated red blood cells, semi-plasma blood and highly concentrated red blood cells can be used; for autoimmune hemolytic anemia or hemolytic transfusion reaction or severe neonatal hemolysis, detergent red blood cells can be used; to exclude autoantibodies, fresh or ordinary frozen plasma can be used for plasma replacement or high-dose intravenous human blood immunoglobulin can be used to counteract.
Evaluation of the efficacy of blood transfusion
The efficacy of blood transfusion should be evaluated mainly based on the improvement or otherwise of clinical symptoms, while the value of blood analysis should be used as a reference.
(A) Evaluation of the efficacy of red blood cell transfusion After transfusion of red blood cells, the improvement of the patient’s clinical symptoms is considered effective. The main purpose of red blood cell transfusion is to eliminate or reduce the clinical symptoms of anemia (panic, shortness of breath, sweating, rapid heart rate, etc.) in anemic patients with normal cardiopulmonary function.
(B) Evaluation of the efficacy of platelet transfusion
1.Although the platelet count is not significantly increased after transfusion, but the clinical bleeding symptoms are significantly improved, it should be considered as effective for transfusion.
2.The platelet count augmentation index (CCI) is greater than 7.5 at 1 hour after transfusion; greater than 4.5 at 18-24 hours, suggesting that the transfusion is effective. CCI less than 7.5 (i.e. less than 7.5-10×109/L) 1 hour after transfusion suggests that the transfusion is not effective.
3. Platelet recovery rate (PPR) is greater than 0.6 at 1 hour and 0.4 at 24 hours after infusion, indicating effective infusion; PPR less than 0.2 at 1 hour after infusion, suggesting invalid infusion.
Note: (1) 1-hour CCI reflects insufficient dose of platelets or the presence of platelet antibodies and hypersplenism; 18-24-hour CCI decrease indicates fever, infection, sepsis, DIC or improper platelet preservation. The calculation formula is.
CCI = [(platelet count after transfusion – platelet count before transfusion) × body surface area]/total number of platelets input (×1011)
(2) PPR reflects the survival of platelets in the body and is calculated by the formula
PPR = [(platelet count after transfusion – platelet count before transfusion) × blood volume] / (total number of platelets input × 0.67)
IV. Contraindications to blood transfusion
Blood transfusion should be strictly controlled, and those who can not be transfused should not be transfused as far as possible. In particular, blood transfusion is prohibited in cases of acute pulmonary edema, pulmonary embolism, congestive heart failure, malignant hypertension and true redness. Be careful with blood transfusion for those with renal insufficiency.
V. Precautions for blood transfusion
(A) Pre-transfusion examination
1.Check the blood type mainly to determine the patient’s ABO blood type. For the first transfusion, or for ethnic groups with more Rho negatives, the Rho blood type should also be determined.
2.Cross-matching: Cross-clotting test with serum and blood cells of the recipient and donor, and only transfusion if negative.
(B) Blood transfusion precautions
1. Use the same type of blood for transfusion as far as possible. In the past, it was unreasonable to call O blood type as universal blood. Only O-type whole blood or washed red blood cells with low serum antibody potency can be transfused to non-O-type patients as a last resort.
2.Two bags of blood from the same donor can be transfused consecutively before and after, while two bags of blood of the same type from different donors should be flushed with a small amount of saline after the first bag has been transfused, followed by the second bag of blood from another donor.
3.Blood is usually stored at 4℃, so its temperature is much lower than the body temperature during transfusion. If it is dripped at medium or slow speed, there is no need to warm it up in advance; however, when the condition requires rapid transfusion, it should be warmed up in a 37℃ water bath before use.
4.Emergency patients should be observed for at least one hour after transfusion before leaving, and if the patient is uncomfortable or discharges soy sauce-colored urine after leaving, he/she should return to the hospital for consultation and treatment quickly.
5.In addition to saline, other intravenous fluids cannot be added to the blood for sedation, so as not to cause adverse reactions.
6. If the blood is too viscous and needs to be diluted, saline or homogeneous plasma is available and any other liquid is prohibited.
VI. Adverse reactions to blood transfusion and acute complications
Most of the adverse reactions to blood transfusion are caused by pyrogen, metaplasia, bacterial contamination and various physical and chemical factors, with an incidence of about 1.2-10%. Urticaria, fever, chills, etc. are the most common. The mortality rate is 0.5-1%.
(A) fever reaction
1. Causes. Immune reaction caused by pyrogen (bacterial metabolites) or multiple blood transfusions or pregnancy resulting in antileukocyte or platelet antibodies in the body.
2. Performance. It occurs immediately after blood transfusion or within a few hours, with chills followed by fever, or even high fever, headache, convulsions and coma. The fever may last 1-2 hours and then gradually improve, and return to normal after 7-8 hours.
3. Prevention and treatment. Can give fenagan 25ml intramuscularly or orally before blood transfusion, or dexamethasone 5mg plus saline 20ml intravenously. When there is fever aura, the transfusion rate should be slowed down; if the symptoms develop, the transfusion must be suspended. For those who have had febrile reactions to blood transfusion and are considering antibody formation, wash red blood cells should be used.
(B) Allergic reaction
(1) Causes Allergic reactions can be caused by the presence of allergens in the blood of the donor and IgE antibodies in the recipient, or by the formation of IgA antibodies in the recipient after multiple transfusions.
(2) Manifestation Urticaria, or fever, sore throat, joint pain, swollen lymph nodes or eosinophilia, angioneurotic edema may appear in the late stage of blood transfusion. In severe cases, laryngeal spasm, branchial croup, respiratory distress, and even death by anaphylaxis.
(3) Prevention and control Do not use blood donors with a history of allergic diseases; fast or eat a small amount of light diet 4 hours before blood supply. In case of allergic blood recipient, use washing red blood cells, and give oral or intramuscular injection of fenugreek 25mg half an hour before transfusion; blood patients can take oral or intravenous injection of corticosteroid such as dexamethasone 5mg; in case of reaction, stop transfusion immediately, use benadryl or fenugreek 25mg, intramuscular injection, or corticosteroid such as dexamethasone 10mg intravenous drip; see asthma, respiratory distress Epinephrine 0.5-1mg should be injected subcutaneously immediately; epiglottis edema should be intubated or tracheotomized immediately and oxygen should be administered; shocked patients should use antihypertensive drugs, etc.
(C) hemolytic reaction is the earliest and serious adverse reaction to blood transfusion
1.Cause
(1) Blood group incompatibility.
(2) Patients with immune hemolytic anemia.
(3) Improper preservation of blood or mechanical damage to red blood cells.
(4) Bacterial infection.
(5) Blood incompatibility between blood donors during mass transfusion.
(6) Addition of hypertonic or hypotonic fluids to the blood to be transfused.
2. Performance
In mild cases, it is difficult to distinguish from febrile reactions, or only transient hemoglobinuria and transient mild jaundice, while in severe cases, typical acute hemolysis, acute renal failure, shock, or even coma and DIC can be seen only after 24 hours. During surgical anesthesia, only traumatic oozing of blood, hemoglobinuria, and decreased blood pressure may be seen, which should raise vigilance.
3.Diagnosis
(1) Check the name of the blood donor and the blood recipient, the bed, the blood type and cross-matching for errors, and check the blood used, the blood matching tube and the blood bag for errors.
(2) Laboratory examination
①When the reaction occurs, 5ml of venous blood can be taken immediately and centrifuged for 1 minute to check whether there is hemolysis in the serum layer.
②If the reaction occurs to the climax, the blood picture can be checked, and the phenomenon of leukocyte engulfment of red blood cells and red blood cell fragments are often seen.
③Take blood specimens before and after transfusion from the donor and the recipient for re-cross-matching, and if possible, Rh factor and Rh antibody should be checked.
④ blood group incompatibility hemolysis within 3-18 hours serum Vanden White test positive in both directions, after that the positive indirect reaction is predominant.
⑤ Positive direct smear or bacterial culture of leftover blood in the bag.
(6) Positive anti-human globulin test, except for autoimmune hemolysis.
4.Prevention
(1) Medical personnel must strengthen their responsibility, never make mistakes in blood type, and avoid other causes of hemolysis.
(2) Do not mix the blood of two or more donors in vitro when transfusing blood to the recipient.
(3) The speed of transfusion should be slow and then fast, and then speed up the drip rate when there is no reaction.
5.Treatment The consequences of hemolytic reaction are serious, and every effort should be made to rescue the patient in time.
(1) When hemolytic reaction is suspected, blood transfusion should be stopped immediately, rehydration should be continued, and blood pressure, respiration, pulse rate and urine volume should be closely monitored.
(2) Immediate subcutaneous or intravenous injection of epinephrine 0.5-1mg.
(3) Dexamethasone 10-20mg, plus saline 20ml intravenously.
(4) Active anti-shock, such as the choice of dopamine, 654-II and other intravenous drip.
(5) alkalinization of urine, with 5% sodium bicarbonate 125ml intravenously.
(6) Administer tachyphylaxis intramuscularly or intravenously to promote bilirubin excretion.
(7) Give dextran to replenish blood volume.
(8) Active prevention and treatment of DIC.
(9) In acute renal failure and uremia, dialysis treatment.
(4) Blood transfusion reaction due to bacterial contamination
1.Cause Blood collection or storage process is contaminated in a certain part of the process.
2, performance Gram-negative bacilli contamination is the most dangerous. Often manifested as toxemia and sepsis. After a few minutes of blood transfusion, chills, high fever, headache, limb pain, irritability, sweating, dyspnea, cyanosis, vomiting, abdominal pain, diarrhea, etc., and even shock, acute renal failure, quite similar to hemolytic reaction.
3.Diagnosis
(1) Small amount of blood transfusion with critical reaction and severe shock.
(2) The blood picture is high in leukocytes and neutrophils, and toxic particles can be seen, but the phenomenon of phagocytosis of red blood cells and red blood cell fragments are not seen.
(3) The blood of the donor and recipient was positive for bacterial culture at 4°C, room temperature and 37°C, respectively.
(4) Urine culture may be positive.
4.Prevention
(1) Pay attention to the strict aseptic operation during blood collection.
(2) The blood plasma is cloudy, flocculent, gray or rose-colored, and bubbles are prohibited.
(3) Once it occurs, symptomatic treatment and supportive therapy should be provided.
(4) Use of adequate, broad-spectrum, effective antibiotics that are sensitive to gram-negative rods.
(5) Intravenous corticosteroid administration.
(6) Anti-shock and acute renal failure.
(E) Complications of massive blood transfusion
(1) Overload of blood circulation. It is common in people with heart disease or severe anemia and in the elderly.
(1) Diagnosis
Sudden respiratory distress, cyanosis, chest tightness, head swelling, pink foamy sputum, pulmonary edema signs such as wet rales in both lungs, and increased heart rate and jugular vein anger are seen during transfusion.
(2) Prevention and treatment
(1) Strictly grasp the indications and contraindications for blood transfusion, control the amount and speed of blood transfusion; concentrated red blood cells should be transfused in congestive heart failure when there are indications for blood transfusion.
②Reducing the transfusion rate to the slowest rate or stopping transfusion for those with symptoms.
③Oxygen absorption.
④Life-threatening patients should be bled as appropriate.
⑤ Anti-heart failure and pulmonary edema refer to the relevant sections.
2.Hemorrhagic tendency Due to the reduction of platelets and coagulation factors by large amount of blood transfusion, fibrinogen and fibrin degradation, etc.
(1) Diagnosis
Intraoperative bleeding, skin purpura, nasal button, blood in urine, etc. can exclude hemolysis and bacterial contamination.
(2) Prevention and treatment
(1) Fresh whole blood or plasma should be transfused for those with pre-existing bleeding tendency and liver disease.
② transfusion of fibrinogen and platelet concentrate if necessary to treat the cause.
(3) Injection of fisetin if caused by heparin.
(3) Others such as citrullosis and hyperkalemia. The former can lead to hypocalcemia and hand and foot clamps, cardiac arrhythmia, etc., and can be prevented by injecting 10% calcium gluconate during massive anticoagulation transfusion; the latter can lead to bradycardia, arrhythmia, and even cardiac arrest, and it is advisable to slow down the transfusion rate when renal insufficiency is present, and to use fresher blood for massive transfusion.
(F) Graft-versus-host disease
It is a rare but serious complication of blood transfusion. It can also be seen after tissue or organ transplantation. Due to immune deficiency, such as after chemotherapy for malignant tumors, transfusion of blood from donors with different histocompatibility antigens of large white blood cells, which contain a large number of immune normal lymphocytes, leads to an immune reaction in the recipient. The prognosis is poor.
1.Diagnosis
(1) manifestations such as high fever, rash, diarrhea, erythema, hepatomegaly, abnormal liver function, and complete blood cytopenia.
(2) Lymphocytic infiltration is seen on skin, rectal and liver biopsy.
2.Prevention and treatment
(1) For simple anemia, transfuse red blood cell products and use less whole blood to reduce the occurrence of the disease.
②Patients can use corticosteroids, anti-lymphocyte globulin or immunosuppressants.
(vii) Blood-borne infectious diseases
Such as acute viral hepatitis, malaria, AIDS, etc. Prevention methods are to implement blood donation according to the law, strict control of blood sources, and strict control of blood transfusion indications.