Hematological Management of Postpartum Hemorrhage

Issue 36 | Volume 1

Postpartum hemorrhage (PPH) remains a leading cause of maternal mortality, responsible for 8% of maternal deaths in the developed world and 20% in developing regions (1). Despite efforts, the rate of PPH requiring blood transfusion has increased in the United States from 8 out of 10,000 deliveries in 1993 to 40 out of 10,000 deliveries in 2014 (2). While the causes for this increase are multifactorial, it is clear that new approaches are needed. One study showed that a comprehensive quality tool kit for hemorrhage could be successfully scaled up to reduce mortality in PPH patients (3). In a similar vein, the American College of Obstetrics and Gynecologists (ACOG) stressed the importance of organized processes to help coordinate PPH management (4). Since a non-insignificant number of PPH patients require intensive care, critical care providers should be cognizant of targets for systematic improvement. Specifically, there are several recent advances in transfusion strategies that this article will focus on.

Tranexamic acid has been finding growing acceptance in the management of hemorrhagic shock and is an easy target for implementation. The WOMAN trial found that TXA administration within three hours of delivery had a mortality benefit in PPH patients without a corresponding increase in thrombosis risk (5). For dosage, the World Health Organization recommends an initial 1 g dose, which can be repeated within 30 to 60 minutes (6). Fibrinogen is the first coagulation factor to decrease in massive obstetrical bleeding, and plasma levels are a good predictor of PPH severity. Several obstetric causes of PPH such as placental abruption, genital tract trauma, amniotic fluid embolism and uterine atony can also lead to rapid fibrinolysis (7). Therefore, early administration of cryoprecipitate should be considered as part of an obstetric-specific transfusion algorithm. Of note, plasma administration alone is inefficient, as 30 mL/ kg is needed to increase the fibrinogen concentration by 1 g/L (7). Newer therapeutics such as fibrinogen concentrates, recombinant factor VII and prothrombin complex concentrates show promise but have yet to show mortality benefit. The benefit of a high plasma to red blood cells transfusion ratio is unclear in recent studies.

However, in the setting of massive transfusion, a 1:1 ratio of plasma to red blood cells is still recommended. The PROPPR trial found that a 1:1:1 (plasma, platelets, red blood cells) transfusion ratio led to better “anatomic” hemostasis compared to 1:1:2 in the setting of massive blood loss (7). Cold-stored, low-titer, type-O whole blood transfusion is an emerging alternative to component- based strategies that is feasible in the obstetric population (8); this may be standardized in non-tertiary centers in the future. Lastly, due to all these considerations, viscoelastic testing can play an important role. It reliably assesses fibrinogen levels in the obstetric population and could be part of a protocol for detection of hyperfibrinolysis or relative factor depletion (9). Obstetric- specific efficacy data is lacking, but decreased blood product utilization can reduce costs as well as the risk of volume overland and transfusion- related acute lung injury.

REFERENCES:

1. Say, L., Chou, D., Gemmill, A., et al. (2014). Global causes of maternal death: A WHO systematic analysis. Lancet Global Health, 2(6), e323ee333.
2. Main EK, Cape V, Abreo A, Vasher J, Woods A, Carpenter A, Gould JB. Reduction of severe maternal morbidity from hemorrhage using a state perinatal quality collaborative. Am J Obstet Gynecol. 2017 Mar;216(3):298.e1-298.e11.
3. Committee on Practice Bulletins-Obstetrics. Practice Bulletin No. 183: Postpartum Hemorrhage. Obstet Gynecol. 2017 Oct;130(4):e168-e186.
4. Ring L, Landau R. Postpartum hemorrhage: Anesthesia management. Semin Perinatol. 2019 Feb;43(1):35-43.
5. Brenner A, Shakur-Still H, Chaudhri R, Muganyizi P, Olayemi O, Arribas M, Kayani A, Javid K, Bello A, Roberts I; I’M WOMAN Trial Collaborative Group. Tranexamic acid by the intramuscular or intravenous route for the prevention of postpartum haemorrhage in women at increased risk: a randomised placebo-controlled trial (I’M WOMAN). Trials. 2023 Dec 3;24(1):782.
6. WHO Recommendations for the Prevention and Treatment of Postpartum Haemorrhage. Geneva: World Health Organization; 2012.
7. Bonnet MP, Benhamou D. Management of postpartum haemorrhage. F1000Res. 2016 Jun 27;5:F1000 Faculty Rev-1514.
8. Morris DS, Braverman MA, Corean J, Myers JC, Xenakis E, Ireland K, Greebon L, Ilstrup S, Jenkins DH. Whole blood for postpartum hemorrhage: early experience at two institutions. Transfusion. 2020 Jun;60 Suppl 3:S31-S35.
9. Huissoud C, Carrabin N, Audibert F, Levrat A, Massignon D, Berland M, Rudigoz RC. Bedside assessment of fibrinogen level in postpartum haemorrhage by thrombelastometry. BJOG. 2009 Jul;116(8):1097-102.

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