Massive Transfusion in Major Obstetric Haemorrhage

Key points

Major obstetric haemorrhage (MOH) is a significant cause of maternal morbidity however there is no consensus on optimal transfusion support for patients with massive haemorrhage.

• Currently there is a drive to adapt the management of massive haemorrhage patients based on the findings of studies carried out on trauma patients although there is no evidence to support this change.
• This study will describe the incidence, management and clinical outcomes of obstetric massive transfusion in the UK and investigate whether any management factors are associated with improved outcomes.

Surveillance Period 1st July 2012 - 30th June 2013

Background

Major obstetric haemorrhage (MOH), resulting in massive transfusion (MT), accounts for 80% of all maternal morbidity^[1]. As there is no universally accepted definition for MOH, its incidence varies depending on how it is defined. The most critical feature of MOH is the development of disseminated intravascular coagulopathy (DIC) which, unlike DIC that follows major haemorrhage in trauma or surgery, occurs quite early on in the course of the haemorrhage. The situation is further complicated by the fact that during massive haemorrhage volume resuscitation with fluid and blood can lead to dilutional coagulopathy^[2].

In recent years, availability of rapid new diagnostic testing and the introduction of new haemostatic resuscitation strategies have challenged our thinking on optimal transfusion support for patients with massive haemorrhage. Much of the drive for new approaches to management of bleeding has come from studies of patients with trauma. In trauma-induced haemorrhage it is now believed that standard MT protocols are less effective in treating major bleeding^[3]. Although studies from bleeding trauma patients have some limitations, they have raised some important questions on the optimum management of patients with massive bleeding. Increasingly, the ‘high-ratio’ protocols are being adapted and applied to patients with other major bleeding (including MOH) with no supporting evidence.

Clinical studies of massive bleeding in trauma have also raised concerns about the role and value of standard coagulation tests (PT, APTT). These are in vitro tests, largely developed and validated for patients with inherited bleeding disorders. Moreover, the time required to obtain their results (~50 min) limits their usefulness in the management of MT and increases its complexity resulting in suboptimal transfusion therapy and maybe contributing to poor outcome.

Further investigation is required to enable the generation of evidence-based clinical guidance, as well as the identification of new avenues for research including, among others, interventional clinical trials.

Objectives

To use the UK Obstetric Surveillance System to investigate what proportion of women who receive MT receive plasma transfusions and whether there is any correlation between the use of additional blood components and clinical outcomes.

Research questions

• What proportion of women who receive MT receive plasma transfusions?
• Is there any correlation between the use of additional blood components and clinical outcomes?
• What are the coagulation abnormalities at the time of the MT?
• Is there any correlation between clinical outcomes and (a) coagulation abnormalities and (b) other products administered.

Case Definition

All pregnant women of 20 weeks gestation or more identified as having >/= 8 units of RBC transfusion (excluding cell salvage) within a 24hr period.

Funding

NHS Blood and Transplant

Ethics committee approval

NRES Committee London – City & East REC Reference: 12/LO/0689

Investigators

Laura Green, NHS Blood and Transplant & Barts and the London Hospital

Simon Stanworth, NHS Blood and Transplant, Oxford

Peter Collins, Cardiff University

Marian Knight, NPEU