If the patient becomes hemodynamically unstable at any point and/or blood loss exceeds 1500 mL:
- Begin transfusion of pRBCs
- Activate institutional massive transfusion protocol if no response to initial blood challenge (2-4 units pRBCs in first hour)
- Obtain obstetric consult for surgical management
Transfusion therapy in the setting of postpartum hemorrhage should be guided by assessment of blood loss and the clinical examination. Considerable changes in vital signs may not be evident until significant blood loss has already occurred. Reliance on laboratory values (specifically hemoglobin or hematocrit levels) to assess blood loss is not recommended, as these values will not reflect acute blood loss in postpartum hemorrhage. Early initiation of blood product transfusion is recommended in patients with postpartum hemorrhage, and immediate transfusion is recommended if there is blood loss ≥1500 mL in a patient with tachycardia or hypotension.
A massive transfusion protocol includes administration of packed red blood cells, plasma, and platelets in a set ratio (eg, 1:1:1, 4:4:1, or 6:4:1). However, there is insufficient evidence to recommend a specific ratio. While the ACOG practice guideline for management of postpartum hemorrhage recommends a 1:1:1 ratio, the guideline also emphasizes the importance of developing an institutional, multispecialty protocol to define a ratio and identify triggers for its use.