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

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

Can a Single-unit Blood Transfusion Protocol in Obstetrics Reduce Total Number of Units Transfused? A Randomized, Controlled Trial

There is a paucity of data on management of non-acute postpartum anemia. Although blood transfusions were historically initiated with 2 units, the most recent recommendation from the American Association of Blood Banks is to begin with 1 unit. As no randomized controlled trials have been performed in obstetrics, the investigators propose a randomized, controlled trial in non-acute postpartum anemia comparing single- versus multiple-unit transfusion by total numbers of units transfused and maternal morbidity.

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.

In this arm, patients receive a 1 unit pRBC transfusion with the plan for post-transfusion blood count at 4-6 hours post-transfusion and clinical reassessment.

In this arm, patients receive 2 units of pRBCs, followed by 4-6 hour post-transfusion blood count and clinical reassessment.

To determine if there is a difference between single-unit and multiple-unit transfusion protocols in total number of units transfused

To determine if there is a difference between single-unit and multiple-unit transfusion protocols in length of stay in days

To determine if there is a difference between single-unit and multiple-unit transfusion protocols in exclusive breastfeeding rates at 4-9 weeks postpartum.

• To determine if there is a difference between single-unit and multiple-unit transfusion protocols in Edinburgh Postnatal Depression Scale score at 4-9 weeks postpartum. EPDS scores range from 0-30, with higher scores (particularly above 10) are indicative of depression.

• To determine if there is a difference between single-unit and multiple-unit transfusion protocols in Multidimensional Fatigue Inventory scores at 4-9 weeks postpartum. This score ranges from 0-140 with higher scores indicating worse fatigue.

• To determine if there is a difference between single-unit and multiple-unit transfusion protocols in Maternal Attachment Inventory scores at 4-9 weeks postpartum. The possible range of scores is 26-104. Higher scores indicate higher maternal attachment to the infant.

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

Carson JL, Stanworth SJ, Dennis JA, Trivella M, Roubinian N, Fergusson DA, Triulzi D, Doree C, Hebert PC. Transfusion thresholds for guiding red blood cell transfusion. Cochrane Database Syst Rev. 2021 Dec 21;12(12):CD002042. doi: 10.1002/14651858.CD002042.pub5.

Hamm RF, Perelman S, Wang EY, Levine LD, Srinivas SK. Single-unit vs multiple-unit transfusion in hemodynamically stable postpartum anemia: a pragmatic randomized controlled trial. Am J Obstet Gynecol. 2021 Jan;224(1):84.e1-84.e7. doi: 10.1016/j.ajog.2020.07.007. Epub 2020 Jul 9.