SMaRT Blood: Single-unit Versus Multiple-unit Packed Red Blood Cell Transfusion in Non-acute Postpartum Anemia

Postpartum hemorrhage (PPH), which accounts for 30% of all direct maternal deaths, is the single most important cause of maternal morbidity and mortality across the globe and is a focus of attention of national organizations such as the Council for Patient Safety in Women's Health in recent years. Yet, there remains a paucity of data on the appropriate management of non-acute postpartum anemia.

It is common practice in obstetrics to offer a transfusion of packed red blood cells (pRBCs) to women with a hemoglobin (Hb) value less than 7 g/dL (hematocrit less than 20%) and to symptomatic women with even higher hemoglobin levels. Although transfusions were historically initiated with 2 units of pRBCs, the most recent recommendation from the American Association of Blood Banks (AABB) for a stable patient is to begin with 1 unit and reassess. However, while surgical data has successfully demonstrated that liberal blood transfusion increases morbidity and mortality in comparison to restricted transfusion, no randomized controlled trials have been performed in obstetrics to demonstrate superiority of a single-unit transfusion protocol.

The investigators propose a randomized, controlled trial in non-acute postpartum anemia comparing single-unit versus multiple-unit transfusion by total numbers of units transfused and maternal morbidity at the University of Pennsylvania with the hypothesis that single-unit transfusions can reduce the number of units transfused without increasing maternal morbidity.

Inclusion criteria

• Women over 18
• Willing and stable to give consent
• > 6 hours postpartum from any mode of delivery
• Determined by their physician to require blood transfusion either by:

• Hb <7g/dL OR
• >7g/dL with any sign or symptom of anemia such as fatigue, dizziness, tachycardia, or hypotension
• Agreed to accept blood transfusion
• No contraindications to blood transfusion

Exclusion criteria

• hemoglobinopathies
• patients with an ejection fraction <35%
• Hb <5 g/dL
• HR > 130 bpm, BP < 80/40