Restrictive vs. Liberal Transfusion: A Meta-Analysis Based on Clinical Context

Some randomized trials have shown that so-called “restrictive” blood transfusion (i.e., allowing hemoglobin level to drop to <7 or <8 g/dL before transfusing) can lower transfusion rates safely. However, the effect of withholding blood transfusion might vary, depending on clinical context. In this meta-analysis, researchers identified 27 randomized trials in which restrictive and liberal blood transfusion thresholds were compared in the following patient populations:

• Group 1: Patients undergoing cardiac or vascular surgeries or procedures (8 trials)

• Group 2: Older patients undergoing orthopedic surgery (9 trials)

• Group 3: Acute-care patients treated in emergency departments or intensive care units (10 trials)

The nonmortality endpoint was a com…