Hébert P C, Wells G, Marshall J, Martin C, Tweeddale M, Pagliarello G, Blajchman M
Critical Care Program, University of Ottawa (Ontario), Canada.
JAMA. 1995 May 10;273(18):1439-44. doi: 10.1001/jama.1995.03520420055038.
To evaluate the effects of a restrictive and a liberal red blood cell (RBC) transfusion strategy on mortality and morbidity in critically ill patients.
Multicenter, prospective, randomized clinical trial.
Sixty-nine normovolemic critically ill patients admitted to one of five tertiary level intensive care units with hemoglobin values less than 90 g/L within 72 hours of admission.
Patients were randomly allocated to one of two RBC transfusion strategies. Hemoglobin values were maintained between 100 and 120 g/L in the liberal transfusion group and between 70 and 90 g/L in the restrictive group.
Primary diagnosis and mean +/- SD age (58.6 +/- 15 vs 59.0 +/- 21 years and Acute Physiology and Chronic Health Evaluation II score (20 +/- 6.2 vs 21 +/- 7.2) were similar in the restrictive and liberal groups, respectively. Daily hemoglobin values averaged 90 g/L in the restrictive group vs 109 g/L in the liberal group (P < .001). The restrictive group received 2.5 U per patient compared with 4.8 U per patient in the liberal group. This represents a 48% relative decrease (P < .001) in RBC units transfused per patient. The 30-day mortality rate was 24% in the restrictive group compared with 25% in the liberal group; the 95% confidence interval around the absolute difference was -19% to 21%. Similar observations were noted for intensive care unit mortality (P = .76) and 120-day mortality (P > .99). In addition, survival analysis comparing time until death in both groups did not reveal any significant difference (P = .93) between groups. Organ dysfunction scores were also similar (P = .44).
In this small randomized trial, neither mortality nor the development of organ dysfunction was affected by the transfusion strategy, which suggests that a more restrictive approach to the transfusion of RBCs may be safe in critically ill patients. However, the study lacked power to detect small but clinically significant differences. Therefore, further investigations of RBC transfusion strategies are warranted.
评估限制性和宽松性红细胞（RBC）输血策略对危重症患者死亡率和发病率的影响。
多中心、前瞻性、随机临床试验。
69例血容量正常的危重症患者，入住五家三级重症监护病房之一，入院72小时内血红蛋白值低于90g/L。
患者被随机分配至两种RBC输血策略之一。宽松输血组的血红蛋白值维持在100至120g/L之间，限制性输血组维持在70至90g/L之间。
限制性输血组和宽松输血组的主要诊断及平均±标准差年龄（分别为58.6±15岁和59.0±21岁）以及急性生理与慢性健康状况评分II（分别为20±6.2和21±7.2）相似。限制性输血组每日血红蛋白值平均为90g/L，而宽松输血组为109g/L（P<0.001）。限制性输血组每位患者接受2.5单位红细胞，而宽松输血组为每位患者4.8单位。这意味着每位患者输注的红细胞单位相对减少了48%（P<0.001）。限制性输血组30天死亡率为24%，宽松输血组为25%；绝对差异的95%置信区间为-19%至21%。重症监护病房死亡率（P=0.76）和120天死亡率（P>0.99）也有类似观察结果。此外，比较两组直至死亡时间的生存分析未发现两组之间有任何显著差异（P=0.93）。器官功能障碍评分也相似（P=0.44）。
在这项小型随机试验中，输血策略既未影响死亡率，也未影响器官功能障碍的发生，这表明对危重症患者采用更严格的红细胞输血方法可能是安全的。然而，该研究缺乏检测微小但具有临床意义差异的能力。因此，有必要对红细胞输血策略进行进一步研究。
