From the Guidelines
The massive transfusion protocol (MTP) should be initiated in postpartum hemorrhage when blood loss exceeds 1500 mL or when there is ongoing bleeding with hemodynamic instability, as this threshold represents approximately 30% of a pregnant woman's blood volume and indicates severe hemorrhage requiring immediate intervention. This recommendation is based on the most recent and highest quality study available, which emphasizes the importance of prompt intervention in severe postpartum hemorrhage to prevent worsening coagulopathy, organ dysfunction, and increased maternal mortality 1.
Key Considerations
- The decision to activate MTP should not be delayed when a patient shows signs of hemodynamic compromise such as tachycardia, hypotension, or altered mental status, even if exact blood loss is difficult to quantify.
- Once activated, the MTP typically provides balanced transfusion of packed red blood cells, fresh frozen plasma, and platelets in a 1:1:1 ratio.
- Laboratory monitoring including complete blood count, coagulation studies, and fibrinogen levels should be performed regularly during resuscitation.
- Concurrent medical management with uterotonics (oxytocin 10-40 units IV, methylergonovine 0.2 mg IM, carboprost 250 mcg IM, or misoprostol 800-1000 mcg rectally) should be administered to address the underlying cause of bleeding.
Additional Recommendations
- Tranexamic acid should be considered in cases of severe postpartum hemorrhage, with an initial dose of 1 g administered intravenously 1.
- Fibrinogen replacement with cryoprecipitate or fibrinogen concentrate should be considered in cases of bleeding with low fibrinogen levels 1.
- Point-of-care testing is preferred for monitoring haemostatic function in obstetric haemorrhage, as laboratory testing may be too slow 1.
From the Research
Quantity of Blood Loss in Postpartum Hemorrhage
The quantity of blood loss that should initiate the massive transfusion protocol in postpartum hemorrhage is a critical consideration.
- According to 2, severe postpartum hemorrhage can be defined as a blood loss of more than 1500 mL to 2500 mL.
- 3 suggests that consideration for blood products replacement in postpartum hemorrhage should be given when blood loss exceeds 1.5 L or when an estimated 25% of blood has been lost.
Initiating Massive Transfusion Protocol
The decision to initiate the massive transfusion protocol is based on the severity of the hemorrhage and the patient's clinical condition.
- 2 recommends that a massive transfusion protocol should be initiated once a woman displays signs of hypovolemia.
- 3 states that in cases of massive hemorrhage, standardized transfusion protocols have been shown to improve maternal morbidity and mortality.
Blood Product Replacement
The replacement of blood products in postpartum hemorrhage is crucial to prevent maternal morbidity and mortality.
- 4 suggests that a higher fresh frozen plasma: red blood cell (FFP:RBC) ratio may be beneficial in massive bleeding.
- 5 recommends that packed red blood cells, fresh frozen plasma, platelets, and cryoprecipitate should be transfused in higher ratios with respect to red cell units than previously recommended.