Early viscoelastometric guided fibrinogen replacement combined with escalation of clinical care reduces progression in postpartum haemorrhage: a comparison of outcomes from two prospective observational studies.

BACKGROUND: Viscoelastometric haemostatic assays (VHA) give rapid information on coagulation status, allowing individualised resuscitation. METHODS: This paper compares outcomes from two observational studies of postpartum haemorrhage (PPH) in the same institution, before and after practice changed from fixed ratio empirical transfusion of coagulation products with laboratory coagulation testing to VHA-guided fibrinogen replacement incorporated into an enhanced PPH care bundle. In both studies, all blood samples were taken near 1000 mL qualitative blood loss (QBL). In Study One, QBL started once PPH was identified, and resuscitation with coagulation blood products was empirical or based on laboratory tests of coagulation. In Study Two, QBL started at delivery and VHA was used to guide fibrinogen replacement if FIBTEM A5 was <12 mm (Claus fibrinogen ≤2 g/L) or to withhold coagulation products if FIBTEM A5 was >12 mm. RESULTS: Improved PPH outcomes were observed in Study Two, with rates of measured blood loss ≥2500 mL, ≥4 units red blood cell (RBC) transfusion, fresh frozen plasma transfusion and ≥8 units of any blood product transfusion all reduced (P < 0.01). Clinically significant improvements occurred in women with fibrinogen ≤2 g/L at study entry, where the proportion of women who received ≥4 units RBC transfusion fell from 67% in Study One to 0% in Study Two (P = 0.0007). CONCLUSIONS: These results suggest that use of VHA as part of an early bundle of PPH care targeting fibrinogen ≤2 g/L with fibrinogen concentrate reduces PPH progression. The greatest benefit was seen when fibrinogen levels were ≤2 g/L at first testing.

The incidence, aetiology, and coagulation management of massive postpartum haemorrhage: a two-year national prospective cohort study.

INTRODUCTION: Between 2017 and 2018 a national quality improvement initiative was introduced incorporating point-of-care viscoelastic haemostatic assays (VHA) to guide blood product transfusion. Laboratory coagulation profiles, use and results of VHA, and administration of blood products were investigated. METHODS: A two-year prospective cohort study of maternal outcomes of women experiencing massive postpartum haemorrhage (PPH) >1000 mL in Wales. In this study, cases of massive PPH (≥2500 mL and/or ≥5 units red blood cell (RBC) transfusion) were identified. RESULTS: Massive PPH occurred in 349 of 60 914 maternities (rate 5.7 per 1000). There were no deaths from PPH. Intensive care unit admission and/or hysterectomy occurred in 34/311 (10.9%) and 16/347 (4.6%), respectively. The leading cause of massive PPH was genital tract trauma (107/349, 30.6%). Two hundred and seventy-nine (80.6%) required RBC transfusion and 79/345 (22.9%) received at least one blood coagulation product. Results of VHA were recorded in 245/349 (70.2%), with 44/98 (44.9%) women tested in the first six months vs 63/77 (81.8%) in the final six months. Hypofibrinogenaemia (Clauss fibrinogen <2 g/L or FIBTEM A5 <12 mm) was observed in 56/328 (17.1%) of women, thrombocytopaenia (count <75 × 109/L) in 17/334 (5.1%) and either PT or aPTT >1.5×reference range in 10/293 (3.4%). CONCLUSION: In Wales, the use of VHA in cases of massive PPH increased over time, enabling clinicians to adopt a targeted, patient-specific approach to blood product administration, with only 22.9% of women receiving blood coagulation products and 17.1% having a documented clotting abnormality.

Rotational thromboelastometry (ROTEM®)-guided diagnosis and management of amniotic fluid embolism.

Amniotic fluid embolism is a rare but often catastrophic emergency. The non-specific clinical features and lack of diagnostic tests make it a diagnosis of exclusion. Point-of-care visco-elastometric testing is being increasingly used during obstetric haemorrhage. We present a case of amniotic fluid embolism, diagnosed and managed using rotational thromboelastography. During a precipitous labour, a 21-year-old multiparous woman became pale, distressed and disorientated. The fetus was delivered using forceps. Simultaneously maternal cardiac arrest occurred and advanced life support was commenced. As there was no obvious bleeding, pulmonary embolism was considered the most likely diagnosis and preparation was made to thrombolyse. During resuscitation, rotational thromboelastometry demonstrated haemostatic failure, supporting a diagnosis of amniotic fluid embolism. This reversed the decision to thrombolyse and focused the team on resuscitation and management of coagulopathy. Targeted blood products were given using a local protocol specific to obstetric bleeding. Return of cardiac output was achieved. The total measured blood loss was more than 3.6 L and transfusion was guided by point-of-care tests. Transfused blood products were six units of packed red blood cells, one pool of platelets, 12 units of fresh frozen plasma and 14 g of fibrinogen concentrate. This case demonstrates amniotic fluid embolism with haemostatic failure, without initial revealed blood loss. The high mortality of amniotic fluid embolism necessitates rapid diagnosis and aggressive management. Laboratory tests in this context are impractical in informing clinical decisions, showing the value of point-of-care testing in facilitating team work and timely administration of targeted blood products.