Use of Blood Components in Major Obstetric Hemorrhage: Preliminary Findings from the Australian and New Zealand Massive Transfusion Registry (ANZ-MTR)
Authors: Aoki Naomi J , Venardos Kylie , Andrianopoulos Nick , Mcquilten Zoe K , Zatta Amanda J , McLintock Claire , Savoia Helen , Wood Erica M 
Published: October 2019

Abstract

Introduction:
Major obstetric hemorrhage (MOH) can develop rapidly and, due to the unique characteristics of maternity patients, early recognition and management can be challenging. Use of blood components in MOH can be life-saving however there is uncertainty about optimal use of these products and the role of adjunctive therapies.
The ANZ-MTR generates observational data on current transfusion management and outcomes in critically bleeding patients receiving massive transfusion (MT) across all clinical settings. This study aimed to describe the transfusion strategies used in the MOH population and report their outcomes.
Methods:
Patients who had a MOH and received a MT (≥5 units of red blood cells [RBC] in 4h) between April 2011 and December 2013 at 15 Australian & NZ hospitals were identified. Data on the type and volume of blood products transfused as well as selected laboratory results and clinical outcomes were reviewed.
Results:
A total of 154 cases were identified and reviewed, representing 6% of the total ANZ-MTR cohort. Median age was 34 [IQR29-37] years and 99% of women had a Charlson Comorbidity Index score ≤ 1. Table 1 presents the blood products transfused. The median [IQR] fresh frozen plasma (FFP) to RBC ratio and platelets to RBC ratio was 0.6 [0.3-0.8] and 0.1 [0-0.2], respectively. FFP, platelets and cryoprecipitate were transfused in 87%, 66% and 49% of patients. Prothrombinex-HT was administered to 1 patient and 3 patients received rFVIIa. Table 2 presents the laboratory results taken prior to MT onset as well as the lowest and highest result reported within 24hours after the MT onset. Fibrinogen levels following MT onset was available for 121 (79%) patients. Of these, 46% women had a fibrinogen level <2 g/L of which 34% did not receive cryoprecipitate. Mean [SD] hemoglobin level 24h post-MT onset was 108g/L [19]. Regarding patient outcomes, median [IQR] hospital length of stay was 8 [4-43] days, 59 (38%) women were admitted to ICU, 40 (26%) underwent a subtotal or total hysterectomy and 3 (1.9%) died in-hospital.
Table 1. Number of patients and median number of units transfused 24h post-MT onset (n = 154). Blood product n (%) Median units (IQR) Red blood cells 154 (100) 7 [6-10] Fresh frozen plasma 134 (87) 4 [2-6] Platelets 102 (66.2) 1 [0-1] Cryoprecipitate 76 (49.4) 0 [0-5]
Table 2. Laboratory values* reported Value prior to MT onset Lowest value 0-24h post-MT onset Highest value 0-24h post-MT onset Hemoglobin (g/L) 102 [81-120], 84 77 [67-90]; 92 108 [95-119]; 92 INR 1.1 [0.9-1.2]; 33 1.1 [.9-1.2]; 72 1.3 [1.1-1.4]; 72 aPPT(s) 31 [28-35]; 39 31 [29-34]; 88 37 [33-46]; 88 Fibrinogen level (g/L) 3.2 [1.6-3.9]; 25 1.9 [1.4-2.6]; 79 2.9 [2.5-3.5]; 79 Platelet Count (109/L) 210 [158-249];84 102 [74-135]; 92 146 [110-190]; 92 pH 7.3 [7.3-7.4]; 22 7.3 [7.2-7.3]; 70 7.4 [7.4-7.5]; 70
*Data are Median [IQR]; % patients with laboratory test available
Conclusion:
Women with MOH requiring massive transfusion were generally healthier and younger than patients of other clinical contexts in the ANZ-MTR. Although there were few in-hospital deaths reported (1.9%), a large proportion of the cohort required a hysterectomy during their hospital admission. Further information on transfusion practice, including understanding optimal blood component ratios, is required to inform clinical practice and minimize risk in the obstetric setting.

Disclosures
McLintock: Novo Nordisk Australasia: Honoraria.