Marik P E, Sibbald W J
AC Burton Vascular Biology Laboratory, Victoria Hospital Research Institute, London, Ontario, Canada.
JAMA. 1993 Jun 16;269(23):3024-9.
Red blood cell transfusion is commonly used to augment systemic oxygen delivery to supranormal levels in patients with sepsis. However, clinical studies have not consistently demonstrated that this therapeutic maneuver is accompanied by an increase in oxygen utilization at either the whole-body level or within individual organs.
To determine the effect of red blood cell transfusion on gastrointestinal and whole-body oxygen uptake.
Prospective, controlled, interventional study.
Multidisciplinary intensive care unit of a tertiary care teaching hospital.
Twenty-three critically ill patients with sepsis undergoing mechanical ventilation.
Systemic oxygen uptake was measured by indirect calorimetry and calculated by the Fick method. Gastric intramucosal pH as measured by tonometry was used to assess changes in splanchnic oxygen availability. Measurements were made prior to transfusion of 3 U of packed red blood cells. These were then repeated immediately following transfusion, as well as 3 and 6 hours later. There was no increase in systemic oxygen uptake measured by indirect calorimetry in any of the patients studied for up to 6 hours posttransfusion (including those patients with an elevated arterial lactate concentration). However, the calculated systemic oxygen uptake increased in parallel with the oxygen delivery in all the patients. More importantly, we found an inverse association between the change in gastric intramucosal pH and the age of the transfused blood (r = -.71; P < .001). In those patients receiving blood that had been stored for more than 15 days, the gastric intramucosal pH consistently decreased following the red blood cell transfusion.
We failed to demonstrate a beneficial effect of red blood cell transfusion on measured systemic oxygen uptake in patients with sepsis. Patients receiving old transfused red blood cells developed evidence of splanchnic ischemia. We postulate that the poorly deformable transfused red blood cells cause micro-circulatory occlusion in some organs, which may lead to tissue ischemia in some organs.
在脓毒症患者中，红细胞输血常用于将全身氧输送量提高到超常水平。然而，临床研究并未始终表明，这种治疗手段会伴随全身水平或单个器官内氧利用率的增加。
确定红细胞输血对胃肠道和全身氧摄取的影响。
前瞻性、对照、干预性研究。
一所三级护理教学医院的多学科重症监护病房。
23例接受机械通气的脓毒症重症患者。
通过间接测热法测量全身氧摄取，并根据菲克法计算。通过张力测定法测量的胃黏膜内pH值用于评估内脏氧供应的变化。在输注3单位浓缩红细胞之前进行测量。然后在输血后立即以及3小时和6小时后重复测量。在输血后长达6小时的所有研究患者中（包括动脉乳酸浓度升高的患者），通过间接测热法测量的全身氧摄取均未增加。然而，所有患者计算出的全身氧摄取与氧输送量平行增加。更重要的是，我们发现胃黏膜内pH值的变化与输注血液的储存时间呈负相关（r = -0.71；P < 0.001）。在那些接受储存超过15天血液的患者中，红细胞输血后胃黏膜内pH值持续下降。
我们未能证明红细胞输血对脓毒症患者测量的全身氧摄取有有益影响。接受陈旧输注红细胞的患者出现内脏缺血的证据。我们推测，可变形性差的输注红细胞会导致某些器官的微循环阻塞，这可能导致某些器官的组织缺血。
