背景:少数进行心脏手术的患者(15%至20%)消耗了手术中输注的80%以上的血液制品。血液必须被视为具有风险和利益的稀缺资源。仔细审查现有证据可以提供指南来分配这一宝贵资源并改善患者预后。
方法:我们回顾了所有已发表的与心脏手术期间血液保护相关的证据,包括随机对照试验,发表的观测信息,和病例报告。常规方法确定了每种血液保护干预措施的可用证据水平。在考虑了证据水平之后,我们使用美国心脏协会/美国心脏病学会分类方案对每项干预措施提出了建议.
结果:对已发表报告的回顾发现了与术后输血增加相关的高风险特征。六个变量是重要的风险指标:(1)高龄,(2)术前红细胞体积低(术前贫血或体型小),(3)术前抗血小板或抗血栓药物,(4)重新手术或复杂的程序,(5)应急操作,(6)非心脏患者合并症。仔细审查显示,术前和围手术期干预措施可能会减少出血和术后输血。可能减少输血的术前干预措施包括识别高危患者,这些患者应接受所有可用的术前和围手术期血液保护干预措施以及限制抗血栓药物。围手术期血液保护干预措施包括使用抗纤维蛋白溶解药物,选择性使用非体外循环冠状动脉搭桥术,细胞保存设备的常规使用,并实施适当的输血指征。一个重要的干预措施是应用基于机构的多模态血液保护计划,被所有医疗保健提供者接受,这涉及到经过深思熟虑的输血算法来指导输血决策。
结论:根据现有证据,特定机构的协议应该筛查高风险患者,因为血液保护干预措施可能对这一高风险子集最有成效。现有的基于证据的血液保护技术包括(1)增加术前血容量的药物(例如,促红细胞生成素)或减少术后出血(例如,抗纤维蛋白溶解剂),(2)保存血液的装置(例如,术中血液回收和血液节约干预),(3)保护患者自身血液免受手术压力的干预措施(例如,自体捐献和等容血液稀释),(4)共识,特定机构的输血算法辅以即时测试,最重要的是,(5)结合以上所有的多模态血液保护方法。
BACKGROUND: A minority of patients having cardiac procedures (15% to 20%) consume more than 80% of the blood products transfused at operation. Blood must be viewed as a scarce resource that carries risks and benefits. A careful review of available evidence can provide
guidelines to allocate this valuable resource and improve patient outcomes.
METHODS: We reviewed all available published evidence related to blood conservation during cardiac operations, including randomized controlled trials, published observational information, and case reports. Conventional methods identified the level of evidence available for each of the blood conservation interventions. After considering the level of evidence, recommendations were made regarding each intervention using the American Heart Association/American College of Cardiology classification scheme.
RESULTS: Review of published reports identified a high-risk profile associated with increased postoperative blood transfusion. Six variables stand out as important indicators of risk: (1) advanced age, (2) low preoperative red blood cell volume (preoperative anemia or small body size), (3) preoperative antiplatelet or antithrombotic drugs, (4) reoperative or complex procedures, (5) emergency operations, and (6) noncardiac patient comorbidities. Careful review revealed preoperative and perioperative interventions that are likely to reduce bleeding and postoperative blood transfusion. Preoperative interventions that are likely to reduce blood transfusion include identification of high-risk patients who should receive all available preoperative and perioperative blood conservation interventions and limitation of antithrombotic drugs. Perioperative blood conservation interventions include use of antifibrinolytic drugs, selective use of off-pump coronary artery bypass graft surgery, routine use of a cell-saving device, and implementation of appropriate transfusion indications. An important intervention is application of a multimodality blood conservation program that is institution based, accepted by all health care providers, and that involves well thought out transfusion algorithms to guide transfusion decisions.
CONCLUSIONS: Based on available evidence, institution-specific protocols should screen for high-risk patients, as blood conservation interventions are likely to be most productive for this high-risk subset. Available evidence-based blood conservation techniques include (1) drugs that increase preoperative blood volume (eg, erythropoietin) or decrease postoperative bleeding (eg, antifibrinolytics), (2) devices that conserve blood (eg, intraoperative blood salvage and blood sparing interventions), (3) interventions that protect the patient\'s own blood from the stress of operation (eg, autologous predonation and normovolemic hemodilution), (4)
consensus, institution-specific blood transfusion algorithms supplemented with point-of-care testing, and most importantly, (5) a multimodality approach to blood conservation combining all of the above.