Transfusion practice in major obstetric haemorrhage: lessons from trauma

Abstract

The management of massive haemorrhage with blood products is changing as evidence arrives from civilian and military trauma. Rapid early replacement of coagulation factors and platelets is now becoming central to improving outcome, usually given in higher ratios with respect to red cell units than previously recommended and using empiric transfusion based on clinical rather than laboratory parameters. The management of three cases of major obstetric haemorrhage based on these principles is presented. Packed red blood cells, fresh frozen plasma, platelets and cryoprecipitate were transfused in the ratios 5:2:2:1, 4.5:1:1:1 and 4.5:2:1:1. Each patient had acceptable full blood count and coagulation results after surgery and all made an uneventful recovery. These outcomes support the opinion that major obstetric haemorrhage can be managed in a similar fashion to blood loss in trauma. Recommendations from the Association of Anaesthetists of Great Britain and Ireland, and the UK National Patient Safety Agency should be considered during major obstetric haemorrhage.

Introduction

Major obstetric haemorrhage is defined as a blood loss of 2500 mL or more, transfusion of five units of red blood cells or treatment of a coagulopathy.1, 2 Obstetric resuscitation often starts with administration of clear intravenous fluids and packed red blood cells (pRBC), following which the use of clotting products and platelets is considered, often guided by coagulation studies that delay treatment.³ The UK National Patient Safety Agency (NPSA) recommends monitoring laboratory blood tests during massive transfusion, but also that administration of blood and blood products should not be delayed while awaiting results.1, 3, 4, 5

Resuscitation of bleeding patients with crystalloid, colloid and plasma-poor pRBC at the same time that clotting factors are being consumed results in the concentration of plasma coagulation factors falling to <40%, and typically occurs before 10 units of pRBC have been given.⁶ Disseminated intravascular coagulopathy in obstetric haemorrhage can also occur early, especially if haemorrhage is not treated rapidly. Early treatment of massive haemorrhage after trauma using fresh frozen plasma (FFP) and pRBC in a 1:1 ratio, current practice in US and British military, is thought to improve survival.6, 7, 8, 9, 10, 11 Military guidelines for haemorrhagic shock also recommend administration of platelets in a 1:1 ratio with pRBC.7, 8, 9, 11

Prevention of coagulopathy should be better than its treatment and requires anticipation.⁶ Some authors advise that replacement of clotting factors should be made on clinical grounds, rather than based on laboratory results.4, 7, 11, 12 The Association of Anaesthetists of Great Britain and Ireland (AAGBI) guideline recommends early infusion of FFP (15 mL/kg) to prevent haemostatic failure and may need to be started if a senior clinician anticipates massive haemorrhage.¹³ This guideline emphasises the importance of preventing haemostatic failure because, once established, standard regimens of FFP infusion are likely to be inadequate and larger volumes will be required with greater risk to the patient and cost implications for the hospital.¹³

For massive obstetric haemorrhage, a ratio of 6:4:1 for pRBC:FFP:platelets has been suggested. If bleeding continues after initial treatment, consideration should be given to increasing the amount of FFP to give a ratio of 4:4:1.⁵ Point-of-care tests can measure haemoglobin concentration and the coagulation profile, and may guide blood product replacement following initial resuscitation. Three cases of major obstetric haemorrhage treated using these principles are described. In each case the patients’ blood results (Table 1, Table 2, Table 3) and fluid replacement (Table 4) are listed.