Section of Pulmonary Diseases, Critical Care and Environmental Medicine, Tulane University School of Medicine, New Orleans, LA, USA.
Multidisciplinary Intensive Care Research Organization (MICRO), St James's University Hospital, Department of Clinical Medicine, Trinity College, Dublin, Ireland.
Transfus Med Rev. 2017 Oct;31(4):205-222. doi: 10.1016/j.tmrv.2017.07.003. Epub 2017 Jul 21.
The transfusion of red blood cells (RBCs) is a common intervention in intensive care unit (ICU) patients, yet the benefits are far from clear in patients with moderate anemia (eg, hemoglobin (Hb) levels of 7-10 g/dL). Determining which of these patients benefit, and how to even define benefit, from transfusion is challenging. As the intended physiological benefit underpinning RBC transfusion is to improve tissue oxygenation, several studies utilizing a wide range of assessment techniques have attempted to study the effects of transfusion on tissue oxygenation and microcirculatory function. The objective of this systematic review was to determine whether RBC transfusion improves tissue oxygenation/microcirculatory indices in the ICU population, and to provide an introduction to the techniques used in these studies. Eligible studies published between January 1996 and February 2017 were identified from searches of PubMed, Embase, Cinahl, ScienceDirect, Web of Science, and The Cochrane Library. Seventeen studies met inclusion criteria, though there was significant heterogeneity in study design, patient population, assessment techniques and outcomes reported. Overall, the majority of studies (11 of 17) concluded that transfusion did not generally improve tissue oxygenation or microcirculation. Inter-individual effects were highly variable, however, and closer review of sub-groups available in 9 studies revealed that patients with abnormal tissue oxygenation or microcirculatory indices prior to transfusion had improvement in these indices with transfusion, irrespective of assessment method. This finding suggests a new strategy for future trials in the ICU: utilizing tissue oxygenation/microcirculatory parameters to determine the need for transfusion rather than largely arbitrary hemoglobin concentrations.
输注红细胞（RBC）是重症监护病房（ICU）患者的常见干预措施，但在中度贫血患者（例如血红蛋白（Hb）水平为 7-10 g/dL）中，输血的益处远不清楚。确定这些患者中的哪些患者受益，以及如何定义输血的益处，这是具有挑战性的。由于输血的预期生理益处是改善组织氧合，因此，许多研究利用广泛的评估技术，试图研究输血对组织氧合和微循环功能的影响。本系统评价的目的是确定 RBC 输血是否改善 ICU 人群的组织氧合/微循环指数，并介绍这些研究中使用的技术。从 PubMed、Embase、Cinahl、ScienceDirect、Web of Science 和 The Cochrane Library 中搜索，确定了 1996 年 1 月至 2017 年 2 月期间发表的符合条件的研究。尽管研究设计、患者人群、评估技术和报告的结果存在显著异质性，但有 17 项研究符合纳入标准。总体而言，大多数研究（17 项研究中的 11 项）得出的结论是输血通常不会改善组织氧合或微循环。然而，个体间的影响差异很大，对 9 项研究中可用的亚组进行更仔细的审查表明，在输血前组织氧合或微循环指数异常的患者，无论采用何种评估方法，这些指数都有所改善。这一发现为 ICU 未来的试验提供了一个新策略：利用组织氧合/微循环参数来确定输血的需求，而不是主要依赖于任意的血红蛋白浓度。
