Things We Do For No Reason: Two-Unit Red Cell Transfusions in Stable Anemic Patients

Perhaps the most common indication for ordering multiunit RBC transfusions is active bleeding, as it is clear that whatever Hb threshold is chosen, transfusion should be given in sufficient amounts to stay ahead of the bleeding.²⁰ It is important to remember that we treat patients and their symptoms, not just their laboratory values. Good medical care adapts and/or modifies treatment protocols and guidelines according to the clinical situation. Intravascular volume is also important to consider because what really matters for oxygen content and delivery is the total red cell mass (ie, the Hb concentration times the blood volume). If a patient is hypovolemic and/or actively bleeding, the Hb transfusion trigger, as well as the dose of blood, may need to be adjusted upward, creating clinical scenarios in which 2-unit RBC transfusions may be appropriate. Other clinical settings for which multiunit RBC transfusions may be indicated include patients with severe anemia, for whom both the pretransfusion Hb (the trigger) and the posttransfusion Hb (the target) should be considered. Patients with hemoglobinopathies (eg, sickle cell or thalassemia) sometimes require multiunit transfusions or even exchange transfusions to improve oxygen delivery. Other patients who may benefit from higher Hb levels achieved by multiunit transfusions include those with acute coronary syndromes; however, the ideal Hb transfusion threshold in this setting has yet to be determined.²¹

For hemodynamically stable patients and in the absence of active bleeding, single-unit RBC transfusions, followed by reassessment, should be the standard for most patients. The reassessment should include measuring the posttransfusion Hb level and checking for improvement in vital sign abnormalities and signs or symptoms of anemia or end-organ ischemia. A recent publication on our hospital-wide campaign called “Why give 2 when 1 will do?” showed a significant (35%) reduction in 2-unit transfusion orders along with an 18% overall decrease in RBC utilization and substantial cost savings (≈$600,000 per year).¹⁰ These findings demonstrate that there is a large opportunity to reduce transfusion overuse by encouraging single-unit transfusions.

• For nonbleeding, hemodynamically stable patients who require a transfusion, transfuse a single RBC unit and then reassess the Hb level before transfusing a second unit.
• The decision to transfuse RBCs should take into account the patient’s overall condition, including their symptoms, intravascular volume, and the occurrence and rate of active bleeding, not just the Hb value alone.

In stable patients, a single unit of RBCs often is adequate to raise the Hb to an acceptable level and relieve the signs and symptoms of anemia. Additional units should be prescribed only after reassessment of the patient and the Hb level. For our patient with symptomatic anemia, it is reasonable to transfuse 1 RBC unit, and then measure the Hb level, and reassess his symptoms before giving additional RBC units.

Do you think this is a low-value practice? Is this truly a “Thing We Do for No Reason?” Share what you do in your practice and join in the conversation online by retweeting it on Twitter (#TWDFNR) and liking it on Facebook. We invite you to propose ideas for other “Things We Do for No Reason” topics by emailing TWDFNR@hospitalmedicine.org.

This publication is dedicated to our beloved colleague, Dr. Rajiv N. Thakkar, who recently and unexpectedly suffered a fatal cardiac event. We will miss him dearly.

Disclosure

S.M.F. has been on advisory boards for the Haemonetics Corporation (Braintree, MA), Medtronic Inc. (Minneapolis, MN), and Zimmer Biomet (Warsaw, IN). All other authors declare no competing interests.