Training material I
New concept of modern surgical blood transfusion
Clinical significance of blood transfusion:
- Improve hemodynamics, increase the oxygen content, and maintain the oxidation process;
- Supplement plasma protein to maintain osmotic pressure and blood volume;
- Increase nutrition to improve the body biochemical function;
- Correct the clotting mechanism, to prevent bleeding;
- As it contains a variety of antibodies, the body’s ability to resist disease can be improved.
Disadvantage of traditional blood transfusion method:
Whole blood is infused regardless of the blood component the patient needs. For example, whole blood is transfused to control hemorrhage (due to coagulation factor deficiency or thrombocytopenia) or control infection (due to granulocyte deficiency), but the whole blood contains limited coagulation factors, platelets or white blood cells, so it is difficult to achieve the expected goal by transfusion of whole blood. Unless a large amount of whole blood is used, the transfusion of large amount of whole blood can increase blood volume and heart burden, and even cause death due to heart failure, pulmonary edema, and severe cases. In addition, infusion of certain undesired components resulted in adverse reactions.
不管患者需要什么血液成分都输注全血。如: 为了控制出血 (因凝血因子缺乏或血小板减少) 或控制感染 (因粒细胞缺乏) 等而输注全血，但全血中所含凝血因子、血小板或白细胞数量有限，输注全血很难达到预期目标，除非用大量全血，而输用大量全血可增加血容量，增加心脏负担，甚至心力衰竭、肺水肿、严重者造成死亡。此外，某些不需要的成分输注后导致不良反应。
The concept of modern blood transfusion: The broad definition includes not only the transfusion of whole blood, various blood cell components and their derivatives, plasma and plasma protein products, but also the transfusion of various blood-related components produced by modern biological technology, such as various hematopoietic factors and plasma protein components produced by DNA recombination technology, and various blood substitutes. The concept of modern blood transfusion also extends from input to removal, that is, the removal of extra or pathologically changed blood cells or other blood components from a patient, such as therapeutic apheresis and plasma exchange.
I. Component blood:
transfusion Whole blood refers to blood collected into containers containing anticoagulants or preservative solutions and obtained without any processing. In the world, 450ml whole blood is generally considered as a unit, while 200ml whole blood is considered as a unit in China.
Whole blood infusion has the following disadvantages:
- The preservative solution prescription of whole blood preservation is only designed to preserve red blood cells, so as long as the blood is extracted, the function of some components begins to be lost.
- Because only albumin in red blood cells and plasma is preserved in whole blood, other components such as platelets, white blood cells, the main coagulation factors in plasma and complement have rapidly or gradually failed. Therefore, its therapeutic effect can only temporarily supplement red blood cells and blood volume to prevent hemorrhagic shock.
- Even if blood is transfused immediately after blood collection, it is impossible to exert the functions inherent to several main components in whole blood because these components do not reach an effective dose in the allowed amount of blood transfusion.
- The sterility of whole blood is guaranteed by the aseptic operation of the blood collection process (including the storage and preparation of blood sampler and blood transfusion device). Practice has proved that “sterile”, it is impossible to reach 100%; Blood products, which can be heated and treated with organic solvents or surface decontaminants by means of microporous membrane filtration techniques, are characteristically “sterile”, and component blood transfusions have been developed to overcome these shortcomings.
全血输注具有如下缺点: (1) 保存全血的保存液处方仅是为保存红细胞而设计的，因此只要血液一经采出，其中某些成分的功能即开始损失。(2) 因为全血中所保存的只是红细胞和血浆中的白蛋白，其他成分如血小板、白细胞、血浆中的主要凝血因子和补体等均已迅速或逐渐失效。故其治疗效果，只能暂时补充红细胞和血容量，防止失血性休克。(3) 即便采血后立即输血，也不可能发挥全血中几个主要成分固有的功能，因为在许可的输血量中这些成分达不到一个有效剂量。(4) 全血的无菌性是靠采血过程 (包括采血器、输血器的储备和准备) 的无菌操作来保证的。实践证明，“无菌”，不可能达到100%；而血液制品 (可借助微孔滤膜过滤技术，加热以及用有机溶剂或表面去污染剂处理) 却可保征“无菌”，因此，为克服以上缺点，出现了成分输血。
Advantages of component transfusion:
- improve curative effect: component transfusion is to carry out what components are lac and what components are added to patients, in particular, that blood component can be purified to obtain a blood product with high concentration, high efficiency and convenient storage and transportation, the same blood components of a plurality of blood donors are mixed together to form an effective therapeutic dose, and the curative effect is remarkably improved after infusion.
- Reducing reaction: The blood composition is complex, and whole blood transfusion can cause various adverse reactions in the recipient. The diseases transmitted by blood transfusion are even more terrible. Component transfusion can avoid transfusion reaction caused by inputting unnecessary blood components. Currently, blood cells separator can be used to separate blood components from one blood donor for transfusion, and other components can be recycled to the blood donor, which can obviously reduce transfusion reaction and reduce transmission diseases. In the elderly, patients with infantile weight and original cardiac insufficiency can reduce blood transfusion volume and cardiovascular load.
- Reasonable use: component transfusion refers to the transfusion of different components of blood to different patients with multiple purposes in one blood. If the various components in whole blood are infused regardless of the needs of patients, the required components are relatively insufficient, and the unnecessary components will be wasted. (4) Economy: using more than one blood can not only save blood, but also reduce the economic burden of society and individuals.
Types of red blood cell products: (I）Oligoplasmic blood， （ii）Concentrated red blood cells，（iii）Substituting plasma blood or crystal salt red blood cells， （iv） Oligoleukocyte red blood cells， （v）Scrubbing red blood cells， （vi）Frozen red blood cells: suitable for the storage of rare blood group and own blood， （vii）Young red blood cells.
Platelet products: （I）Platelet-rich plasma， （ii）Platelet concentrates， （iii）WBC-less platelets.
红细胞制品种类：1. 少浆血 2. 浓缩红细胞 3. 代浆血或晶体盐红细胞 4. 少白细胞的红细胞 5.洗涤红细胞 6. 冰冻红细胞: 适于稀有血型和自身血的贮存 7. 年轻红细胞。
血小板制品：1. 富含血小板血浆 2.浓缩血小板 3. 少白细胞的血小板。
The temperature was kept at 22 C (2 C above and below) with a PH of 6.5-7.2.
In recent years, due to the attention paid by social and medical circles to the transmission of blood transfusion diseases, especially the hepatitis and AIDS after blood transfusion, autotransfusion has risen to an important position, and it is considered to have the following advantages:
- the transmission of blood transfusion diseases such as viral hepatitis, AIDS and cytomegalovirus can be avoided;
- The alloimmune reaction caused by red blood cells, white blood cells, platelets and protein antigens can be avoided;
- hemolytic fever, allergy or graft-versus-host reaction sensitized by immune action can be avoided;
- The error accident of allogeneic blood transfusion can be avoided;
- The unused blood can be transfused to other patients who need transfusion, which increases the blood supply and source.
- patients with autotransfusion because of repeated bleeding, can stimulate red blood cell regeneration, make the patient after surgery hematopoietic speed faster than before;
- The collection and long-term preservation of self blood can provide blood storage for patients with rare blood group when they need blood transfusion;
- Autoblood collection can provide blood for surgery in remote areas without blood supply conditions;
- Some acute internal bleeding, such as rupture of spleen, liver and ectopic pregnancy, can be reinfused under strict conditions without need of anticoagulation (fibrin blood), thus leading to emergency rescue.
近几年来，由于社会和医务界对输血的疾病传播，特别是输血后肝炎和艾滋病的关注，自身输血已上升到一个重要位置，认为它具有以下优点: (1) 可以避免输血的疾病传播，如病毒性肝炎、艾滋病、巨细胞病毒等；(2) 可以避免红细胞、白细胞、血小板以及蛋白抗原产生的同种免疫反应; (3) 可以避免由于免疫作用而致敏的溶血发热，过敏或移植物抗宿主反应; (4) 可以避免发生输同种异体血的差错事故；(5) 自身血没有用完可以输给其它需要输血的患者，增加了血液供应和来源; (6) 自身输血患者由于反复放血，可以刺激红细胞再生，使患者手术后造血速度比手术前快；(7) 自身血的采集和长期保存，可为稀有血型患者需输血时提供贮血；(8) 自身血采集可为无供血条件的边远地区外科手术提供血源；(9) 某些急性内出血，如脾、肝及宫外孕破裂等，在严格条件下可回输且无需抗凝(脱纤维蛋白血)，可达到应急救命。
Frequency of blood collection:
The maximum time required for mobilizing protein to enter plasma and restoring plasma volume to normal is 72 hours. Therefore, except for special circumstances, the frequency of blood collection should be no less than 3 days at the interval between two times. It is best to collect blood one week before surgery. Blood collection should be conducted at least as of 72 hours before surgery. Four to five units of blood are generally allowed.
3. Surgical blood transfusion
外科输血目的有二: 一是纠正血容量; 二是纠正某种血液成分的缺乏。
2、输用库血多。一般库血指采集 24h 后的血制品。(血小板止血功能明显下降、凝血因子的活性下降、血K变化，PH值)
Surgical blood transfusion has two purposes: one is to correct blood volume; the second is to correct the lack of a blood component.
Surgical blood transfusion features:
- large amount of blood loss. The amount of blood loss can be estimated from heart rate, arterial blood pressure, urine volume, central venous pressure, and hematocrit.
- There is much blood in the transfusion reservoir. General blood storage refers to the blood products after 24h collection. (significant decrease in platelet hemostatic function, activity of coagulation factors, blood K change, PH value)
- blood transfusion speed is fast.
3、大量输血时 (>3000ml)，库血与新鲜血 (贮存<24h) 的比例应为3:1，比例2:1则更佳。
4、严重肝功损害者，如总蛋白量 <45g/l、白蛋白 <25g/l 或白球比例倒置应适当补充血浆或白蛋白，术前应争取血红蛋白高于 100g/l，红细在 3×1012/l 以上，血清总蛋白在 60g/l，白蛋白在30 g/l 以上。
3.1. Surgical blood transfusion guidelines
3.1.1. to the abdominal cavity parenchyma organ surgery and vascular injury surgery, appropriate convention with thick needle open two venous channels, to ensure the speed of blood transfusion. The forearm, anterior elbow and cephalic vein can be selected for venipuncture, so as to facilitate the return of supplemented blood from the superior vena cava to the right heart and prevent blood transfusion of the lower limb from entering the abdominal cavity through the vascular rupture in the abdominal cavity.
3.1.2. should be within our means, lost how much how much, speed should be fast shoulds not be slow.
3.1.3. For massive blood transfusion (> 3000ml), the ratio of pooled blood to fresh blood (stored < 24h) should be 3:1, and the ratio of 2:1 is better.
3.1.4. severe liver damage, such as total protein content < 45g/l, albumin < 25g/l or white ball ratio inversion cases should be appropriate to supplement plasma or albumin, preoperative hemoglobin should be higher than 100g/l, fine red in more than 3 x 1012/l, serum total protein in 60g/l, albumin in more than 30 g/l.
3.1.5. bleeding caused by thrombocytopenia, also should input platelet concentrate.
3.1.6. In case of trauma to the parenchymal organs and blood vessels in the abdominal cavity, a large amount of blood may remain in the abdominal cavity, which may be transfused under strict conditions; Partial splenic blood can also be recovered after splenectomy.
3.2. preoperative preparation and component transfusion
Many patients are accompanied by anemia before operation. The degree of anemia varies. Of course, in severe cases, hemoglobin must be added to a certain level before the operation can be tolerated. The preoperative hemoglobin level should be reached depends on the comprehensive evaluation of the patient.
Animal experiments have shown that left ventricular function is inhibited when the blood protein concentration falls below 100g/l, but oxygen uptake, mixed venous oxygen tension, and coronary sinus oxygen tension remain unchanged until the hemoglobin falls to 70-80 g/L. This indicates that when the hemoglobin concentration is maintained above 70 to 80 g/L, most operations can still be performed as usual. The hemoglobin level of 70-80g/l requires normal heart, lung, liver and kidney functions, and any organ dysfunction requires a corresponding increase in hemoglobin level. It has been found that patients with septic shock have the highest survival rate when the hemoglobin concentration is maintained at 125 to 150 g/L, while patients with acute respiratory failure have a significant reduction in mortality when the hemoglobin concentration is maintained at 130 to 160 g/L. Therefore, for patients with organ dysfunction, the level of hemoglobin supplementation depends on clinical conditions.
However, due to the improvement of anesthesia methods and the improvement of anesthesia level, the requirements for hemoglobin can be specific and flexible to master according to the patient’s situation, anesthesia methods and surgical characteristics. For patients who urgently need surgery for acute hemorrhage, immediate surgery should be performed to stop bleeding and blood transfusion should be performed simultaneously with the surgery.
动物实验表明，当血蛋白浓度降至 100g/l 以下时，左心室功能受到抑制，但直至血红蛋白降至70-80g/l 前，氧摄取率、混和静脉血氧张力及冠状窦氧张力仍保持不变。这表明，当血红蛋白浓度保持在 70-80g/l 以上时，绝大部分手术仍可照常进行。70-80g/l 的血红蛋白水平，要求有正常的心、肺、肝、贤功能，任何脏器功能的不全，均要求相应提高血红蛋白水平。有人发现，脓毒性休克患者，当其血红蛋白浓度保持在 125-150g/l 时存活率最高，急性呼吸衰竭患者当其血红蛋白浓度保持在 130-160g/l 时死亡率可明显下降，因此伴脏器功能不全者，补充血红蛋白到什么水平依临床而定。
在外科领域，由于手术范围的扩大，术中失血量大，而需要补充血容量机会增多。血量丢失，当然是失血性休克的主要原因，因此“失血补血”的概念曾长期为术者所遵循，以致大量输入血液而忽视细胞外液的补充，致使休克后肾功能衰竭的发生机会增多。近年来大量实验和临床观察表明，严重创伤或复杂的手术，不但丢失全血，而且也使大量功能性细胞外液转移到第三间隙，并使血液浓缩。即使有低血容量休克的病人，输入全血也不如先输入类似细胞外液的晶体溶液见效迅速。所以一般成人手术，失血量在500ml以内，仅补充3倍量晶体液 (如乳酸钠林格液、林格液或生理盐水) 即可满足要求。失血量在500-1000ml，还应追加一半胶体溶液 (如羟乙基淀粉、右旋糖酐等)。失血量超过1000ml，才需要同时输全血或浓缩血细胞。现在已一致认识到失血时不必过早大量输血，应先以代血浆及晶体液扩充血容量使血液稀释，这样还可增加心输出量，降低周围血管阻力，血流速度加快，增加组织灌注，同时还可防止微循环血流障碍。因此临床上改变了“失血补血”概念。
3.3. New concept of surgical blood transfusion
Blood transfusion, anesthesia and sterility were once considered as the three main factors to promote the development of surgery. With the guarantee of blood transfusion, greatly expand the scope of surgery, correctly grasp the intraoperative blood transfusion can quickly correct blood loss, ensure the success of the operation and the safety of the patient, blood transfusion to the development of surgery plays an increasingly important role. However, because surgical blood transfusion has the characteristics of large blood transfusion volume, large amount of transfused blood and rapid blood transfusion, and the incidence of complications of blood transfusion is relatively high, it has attracted more and more attention from surgeons. In particular, through the in-depth research on blood transfusion over the past decade, the concept of surgical blood transfusion has changed greatly, and great progress has been made in component blood transfusion and autologous blood transfusion.
3.3.1. Change of the concept of “blood loss and enrichment”
In the field of surgery, due to the expansion of the scope of the operation, the amount of blood loss during the operation is large, and the chance of needing to supplement blood volume is increased. Loss of blood volume is, of course, the main cause of hemorrhagic shock. Therefore, the concept of “blood loss and blood enrichment” has been followed by surgeons for a long time, so that a large amount of blood was input while extracellular fluid supplement was ignored, resulting in an increased incidence of renal failure after shock. In recent years, a large number of experiments and clinical observations have shown that severe trauma or complicated surgery not only loses whole blood, but also causes a large amount of functional extracellular fluid to be transferred to the third space and causes blood concentration. Even in patients with hypovolemic shock, the introduction of whole blood is not as effective as the introduction of a crystalloid solution resembling extracellular fluid. Therefore, for general adult surgery, the blood loss should be within 500ml, and only three times of crystal solution (such as sodium lactate Ringer’s solution, Ringer’s solution, or normal saline) can be replenished to meet the requirements. The blood loss ranged from 500 to 1000 mL, and half of the colloidal solution (such as hydroxyethyl starch and dextran) should be added. The amount of blood loss exceeded 1000ml, and the simultaneous transfusion of whole blood or concentrated blood cells was required. It has now been unanimously recognized that it is not necessary to conduct a large amount of blood transfusion prematurely during blood loss; instead, plasma and crystalloids should be replaced to expand the blood volume to dilute the blood, which will also increase cardiac output, reduce peripheral vascular resistance, accelerate blood flow, increase tissue perfusion, and prevent microcirculatory blood flow disturbance. Therefore, that concept of “blood los and blood enrichment” was changed clinically.
自体输血有近百年历史，但近十余年来的临床和实验研究进展较快，技术设备有较大改进，适应范围不断扩大。今已公认为有临床实用价值的治疗方法，自体输血可解决急需输血而血源短缺的困难，无输血反应，并发症少，无传播的危险。更重要的是不产生对红细胞，白细胞、蛋白抗原等血液成分的免疫反应。人们公认自体输血不需化验血型及交叉试验，能及时有效地将丧失血液重新利用，自身的红细胞活力较库血好、运氧能力高。输后红细胞能立即发挥良好的携氧能力。自体输血主要适应于 (1) 胸腔心血管外伤性手术; (2)肝、脾破裂，异位妊娠破裂，肠系膜血管破裂等腹腔出血; (3)体外循坏心内直视手术，主动脉瘤手术等某些择期手术。近年来已发展到术前数天，或麻醉前采集病人血液，用电解质或血浆增量剂补充血容量的“血液稀释法”。血液稀释疗法主要是通过静脉输液，降低患者红细胞压积和血液粘度，加速血流，改善微循环和组织供氧，以达到治疗目的。在外科手术中应用血液稀释技术，还可以大大节约手术中输血量和减少输血并发症的发生。
3.3.2. autologous blood transfusion
Autologous blood transfusion has a history of nearly one hundred years. However, clinical and experimental research has made rapid progress in the past ten years, with great improvements in technical equipment and an ever-expanding scope of application. It has been recognized as a treatment with clinical practical value. Autologous blood transfusion can solve the difficulty of blood shortage due to urgent need of blood transfusion. There is no transfusion reaction, few complications and no risk of transmission. It is more important not to produce immune response to red blood cells, white blood cells, protein antigens and other blood components. It is generally recognized that autotransfusion does not need blood type tests and cross tests, can timely and effectively reuse the lost blood, and has better red blood cell viability and oxygen transport capacity than reservoir blood. After transfusion, red blood cells can immediately exert good oxygen carrying capacity.
Autotransfusion is mainly suitable for (i) thoracic cardiovascular traumatic surgery; (ii) Liver and spleen rupture, ectopic pregnancy rupture, mesenteric vascular rupture and other abdominal hemorrhage; (iii) Some elective operations such as extracorporeal circulation followed by open heart surgery and aortic aneurysm surgery. In recent years, “hemodilution” has been developed in which a patient’s blood is collected several days before surgery or before anesthesia, and blood volume is supplemented with electrolytes or plasma extenders. Hemodilution therapy is mainly through intravenous infusion, reduce the patient’s hematocrit and blood viscosity, accelerate blood flow, improve microcirculation and tissue oxygen, in order to achieve the purpose of treatment. Application of hemodilution technique in surgery can also greatly save blood transfusions during surgery and reduce the occurrence of transfusion complications.
近年来，输血疗法已进入成分输血。成分输血是把全血或血浆用物理的和/或化学方法分离并制成较纯和较浓的各种制品以供临床应用。传统的输血方法是不问病人确实需要什么而千篇一律输血，这样不仅浪费血液，而且还使病人冒不必要的风险。成分输血优点是 (1) 提高输血效果，减轻心脏负担；(2) 减少对不需要的血液成分的反应; (3) 可以达到一血多用，节约用血的目的。成分输血是现代医药和输血发展的必然进程。外科成分输血主要是输用浓缩红细胞。目前对于体循环血容量的恢复和维持，有较好的血浆代用品 (羟乙基淀粉、左旋糖酐等) 或晶体溶液，但都不具有携氧功能，常需要补充红细胞。因此，浓缩红细胞是外科成分输血最常用的，在输血先进的国家，全血的使用已减少到总输血量的20%以下，而浓缩红细胞用量 >80%。
输红细胞为主的输血疗法具有科学性，可行性和一定的先进性，是外科输血的必然趋势。对于接受大手术或严重创伤治疗者，如果血小板低于 50×109/l，为预防术中异常渗血，术前宜预防性浓缩血小板输血，使血小板数升至100×109/l以上。因骨髓功能衰竭引起的血小板减少症，如癌肿化疗或放疗、急性白血病发作期、再生障碍性贫血等，血小板数可低达30×109/l，一般尚不致自发性出血。但如果决定手术，则宜预防性浓缩血小板输血。大量 (15-20单位) 输注冷藏库血，血小板功能几乎完全丧失，更可出现稀释性血小板减少，亦宜输注较大量浓缩立小板预防出血。
3.3.3. component blood transfusion
In recent years, transfusion therapy has entered component transfusion. Component transfusion refers to the physical and/or chemical separation of whole blood or plasma and preparation of various purer and thicker products for clinical application. The traditional method of blood transfusion is to transfuse the blood without asking the patients what they really need. This not only wastes blood, but also makes patients take unnecessary risks. Component blood transfusion has that advantage of (1) improving blood transfusion effect and reduce heart burden; (2) reducing reaction to unwanted blood components; And (3) the purposes of multipurpose with one blood and saving blood can be achieved. Component blood transfusion is an inevitable process of modern medicine and blood transfusion development. Surgical component transfusions are primarily transfusions of packed red blood cells. At present, there are good plasma substitutes (hydroxyethyl starch, dextran, etc.) or crystal solutions for the recovery and maintenance of systemic circulating blood volume, but none of them has oxygen-carrying function, and erythrocyte supplementation is often required. Therefore, packed red blood cells are the most commonly used for surgical component transfusion, and in countries with advanced transfusion, the use of whole blood has been reduced to less than 20% of the total transfusion volume, while the use of packed red blood cells is greater than 80%. The transfusion therapy based on red blood cell transfusion is scientific, feasible and advanced to a certain extent, which is the inevitable trend of surgical blood transfusion. For patients undergoing major surgery or severe trauma treatment, if the platelets are less than 50×109/l, in order to prevent abnormal bleeding during the operation, preoperative prophylactic platelet concentrate transfusion is recommended to increase the platelet count to more than 100 × 109/L. Thrombocytopenia caused by bone marrow failure, such as cancer chemotherapy or radiotherapy, acute leukemia onset, aplastic anemia, platelet count can be as low as 30×109/l, generally does not cause spontaneous bleeding. However, if surgery is decided, prophylactic platelet concentrate transfusion is advisable. If a large amount (15–20 units) of blood is infused into the refrigerator, the platelet function will be almost completely lost, and dilutive thrombocytopenia may occur. It is also advisable to infuse a relatively large amount of concentrated riser to prevent bleeding. Since the end of the seventy, plasma has been widely used in the treatment of a variety of poisoning disorders, plasma used to remove toxic shock during the operation, and to supplement some may be missing components, such as the operation with fresh frozen plasma, containing a variety of plasma coagulation factors. Plasma derivatives include plasma protein solutions, albumin, factors VIII, IX, and gamma globulin. It should be noted that the application of lyophilized plasma in China was excessive, and the most unreasonable one was for blood volume expansion and nutritional supplement. The greatest danger of plasma is the spread of hepatitis, aids and other infectious diseases. There were many adverse reactions in plasma, especially urticaria and allergic reaction. The composition of the plasma is complex, some eggs can produce antibody sensitization patients, in addition is also a great waste. Therefore, whether fresh frozen plasma or lyophilized plasma cannot be easily used.