Aetiology and outcome of massive transfusion in two large London teaching hospitals over a 3-year period (2012-2014)

Definitions of massive transfusion in adults with critical bleeding: a systematic review

BACKGROUND

Definitions for massive transfusion (MT) vary widely between studies, contributing to challenges in interpretation of research findings and practice evaluation. In this first systematic review, we aimed to identify all MT definitions used in randomised controlled trials (RCTs) to date to inform the development of consensus definitions for MT.

METHODS

We systematically searched the following databases for RCTs from inception until 11 August 2022: MEDLINE, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Cumulative Index to Nursing and Allied Health Literature, and Transfusion Evidence Library. Ongoing trials were sought from CENTRAL, ClinicalTrials.gov, and World Health Organisation International Clinical Trials Registry Platform. To be eligible for inclusion, studies had to fulfil all the following three criteria: (1) be an RCT; (2) include an adult patient population with major bleeding who had received, or were anticipated to receive, an MT in any clinical setting; and (3) specify a definition for MT as an inclusion criterion or outcome measure.

RESULTS

Of the 8,458 distinct references identified, 30 trials were included for analysis (19 published, 11 ongoing). Trauma was the most common clinical setting in published trials, while for ongoing trials, it was obstetrics. A total of 15 different definitions of MT were identified across published and ongoing trials, varying greatly in cut-offs for volume transfused and time period. Almost all definitions specified the number of red blood cells (RBCs) within a set time period, with none including plasma, platelets or other haemostatic agents that are part of contemporary transfusion resuscitation. For completed trials, the most commonly used definition was transfusion of ≥ 10 RBC units in 24 h (9/19, all in trauma), while for ongoing trials it was 3-5 RBC units (n = 7), with the timing for transfusion being poorly defined, or in some trials not provided at all (n = 5).

CONCLUSIONS

Transfusion of ≥ 10 RBC units within 24 h was the most commonly used definition in published RCTs, while lower RBC volumes are being used in ongoing RCTs. Any consensus definitions should reflect the need to incorporate different blood components/products for MT and agree on whether a 'one-size-fits-all' approach should be used across different clinical settings.

Calcium Chloride Requirement and Postreperfusion Rebound During Massive Transfusion in Liver Transplantation

OBJECTIVES

The administration of citrated blood products during massive transfusion requires calcium salt administration to prevent citrate toxicity and to maintain ionized calcium values. The literature does not provide adequate guidance for the amount of calcium required during massive transfusions during liver transplantation. This study was conducted to provide guidance on calcium salt replacement during a massive transfusion in liver transplant patients, with a focus on the phase of transplantation during which citrate metabolism was minimal.

DESIGN

An observational retrospective chart review.

SETTING

An academic single-institution study of hospitalized patients.

PARTICIPANTS

One hundred thirty-two patients after liver transplantation.

INTERVENTIONS

The study authors observed documented measurements of ionized calcium and observed the ratio of calcium salts to citrated bank blood products in patients undergoing liver transplantation with complete data sets. They also observed the effect of continuous venovenous hemofiltration on the distribution of ionized calcium values.

MEASUREMENTS AND MAIN RESULTS

Prereperfusion, an average of 1.09 g CaCl₂/L of citrated blood was administered to maintain ionized calcium in the normal range. Postreperfusion, less CaCl₂ was administered, and a rebound of ionized calcium occurred. Prereperfusion, continuous venovenous hemofiltration reduced the number of ionized calcium values outside of 2 standard deviations, meaning fewer values were critically low.

CONCLUSIONS

With massive transfusions up to 67 liters (approximately 13 blood volumes), 1.09 g CaCl₂/L citrated blood maintained ionized calcium in the normal range in the absence of citrate metabolism. This ratio may have value in empiric treatment when ionized calcium measurements are unavailable, and massive transfusion rates exceed metabolic capacity.

Factors Associated With Mortality Among Patients Managed for Large Volume Hemorrhage in a Medical Intensive Care Unit

PURPOSE

Our goal was to describe resuscitation practices in critically ill medical patients with active hemorrhage requiring large volume resuscitation and identify factors associated with poor outcomes.

PATIENTS AND METHODS

This was a single center retrospective observational cohort study. Patients admitted to the medical intensive care unit from 2011 to 2017 who received ≥5 units of packed red blood cells (pRBCs) within 24 h were included. Data including volume of blood products and crystalloid administered, baseline sequential organ failure assessment (SOFA) scores, and outcomes were abstracted. Univariate and multivariate analyses were performed to determine clinical factors associated with hospital mortality.

RESULTS

Two hundred forty-six patients were identified. Mean volumes of 2,448 mL of pRBCs and 3.9L of crystalloid were transfused over 24 h. Inpatient mortality for the entire cohort was 48%. Multivariable analysis identified factors associated with hospital mortality; higher BMI (OR 1.047, 95% CI 1.013-1.083), higher ratio of fresh frozen plasma (FFP) to pRBCs (OR 2.744, 95% CI 1.1-6.844), and higher baseline SOFA scores (OR 1.3, 95% CI 1.175-1.437).

CONCLUSION

In a cohort of critically ill medical patients undergoing resuscitation for hemorrhage, higher BMI, increased ratio of FFP to pRBCs, and higher SOFA scores were associated with increased mortality. Further studies are needed to clarify resuscitation practices associated with outcomes in this population.

Epidemiology of Massive Transfusion - A Common Intervention in Need of a Definition

While massive transfusion (MT) recipients account for a small proportion of all transfused patients, they account for approximately 10% of blood products issued. Furthermore, MT events pose organizational and logistical challenges for health care providers, laboratory and transfusion services. Overall, the majority of MT events are to support major bleeding in surgical patients, trauma and gastrointestinal hemorrhage. The clinical context in which the bleeding event occurred, the number of blood products required, patient age and comorbidities are the most important predictors of outcomes for short- and long-term survival. These data are important to inform blood services, clinicians and health care providers in order to improve care and outcomes for patients with major bleeding. There is no standard accepted definition of MT, with most definitions based on number of blood components administered within a certain time-period or activation of MT protocol. The type of definition used has implications for the clinical characteristics of MT recipients included in epidemiological and interventional studies. In order to understand trends in incidence of MT, variation in blood utilization and patient outcomes, and to harmonize research outcomes, a standard and universally accepted definition of MT is urgently required.

Transfusion Requirements and Blood Bank Support in Heart and Lung Transplantation

OBJECTIVE

Transplantations may require massive transfusion of blood products. Therefore, blood banks need to predict, prepare, and supply the required amount of blood products.

METHODS

We measured the volume of transfused blood components as red blood cells, fresh frozen plasma, platelets, and cryoprecipitate in 54 and 89 patients who received heart and lung transplantation, respectively, in our hospital between January 2012 and December 2019.

RESULTS

Platelets were the most frequently transfused blood component. Transfusion volumes during heart and lung transplantation surgeries differed: red blood cells, 7.83 units vs 14.84 units; fresh frozen plasma, 2.67 units vs 12.29 units; platelets, 13.13 units vs 23.63 units; and cryoprecipitate, 1.74 units vs 2.57 units; respectively. The average transfusion volume of transplants was different each year.

CONCLUSION

Periodic evaluation of transfusion requirements will facilitate the efficient management of blood products at the time of transplantation and help blood banks predict changes in blood requirements.

MATRA-A: A study on massive transfusion

BACKGROUND

We use massive transfusion in various clinical conditions and it is associated with high mortality. Although some massive transfusion protocols improve patient outcomes, the clinical circumstances requiring it are not well defined.

METHODS

MATRA-A is a multicenter retrospective study. Six University and Training Research Hospitals in Ankara participated in the study. We collected clinical data on patients (>18 years) who received massive transfusions (≥10 units/24 h) from 2017 through 2019.

RESULTS

Overall, 167 (0·27% of transfused patients) received a massive transfusion of 2586 units of red blood cells (1·5% of total RBCs transfused). The median interquartile range values for RBCs, fresh frozen plasma (FFP) and platelets were 13 (11-176), 16 (9-33) and 4 (0-11), respectively. Surgical patients received 90% of massive transfusions. The most common clinical indications for massive transfusion were cardiovascular diseases (42·6%), trauma (20·3%) and malignancies (11%). FFP: RBC: Platelets ratio was 1·9:1:0·5. The overall and trauma-related mortality rates were 57·4% and 61·8%, respectively. The hospital mortality rates of trauma patients that received high vs. low ratio (FFP: RBCs > 1:1·5 vs. ≤1:1·5) transfusions were 47·6% and 86·6% and the difference was statistically significant (P = 0·03).

CONCLUSION

Cardiovascular diseases and trauma occasion are the most common causes of massive transfusion. It is infrequent in clinical settings and is associated with high mortality rates. Additionally, in massively transfused trauma patients, a high FFP:RBCs ratio seems to be associated with increased survival. Focused prospective studies are required to define the areas that need improvement on a national scale.

Outcome of Major Hemorrhage at a Major Cardiothoracic Center in Patients with Activated Major Hemorrhage Protocol versus Nonactivated Protocol

This study aimed to determine the impact of major hemorrhage (MH) protocol (MHP) activation on blood administration and patient outcome at a UK major cardiothoracic center. MH was defined in patients (> 16 years) as those who received > 5 units of red blood cells (RBCs) in < 4 hours, or > 10 units in 24 hours. Data were collected retrospectively from patient electronic records and hospital transfusion databases recording issue of blood products from January 2016 to December 2018. Of 134 patients with MH, 24 had activated MHP and 110 did not have activated MHP. Groups were similar for age, sex, baseline hemoglobin, platelet count, coagulation screen, and renal function with no difference in the baseline clinical characteristics. The total number of red cell units (median and [IQR]) transfused was no different in the patients with activated (7.5 [5-11.75]) versus nonactivated (9 [6-12]) MHP (p = 0.35). Patients in the nonactivated MHP group received significantly higher number of platelet units (median: 3 vs. 2, p = 0.014), plasma (median: 4.5 vs. 1.5, p = 0.0007), and cryoprecipitate (median: 2 vs. 1, p = 0.008). However, activation of MHP was associated with higher mortality at 24 hours compared with patients with nonactivation of MHP (33.3 vs. 10.9%, p = 0.005) and 30 days (58.3 vs. 30.9%, p = 0.01). The total RBC and platelet (but not fresh frozen plasma [FFP]) units received were higher in deceased patients than in survivors. Increased mortality was associated with a higher RBC:FFP ratio. Only 26% of patients received tranexamic acid and these patients had higher mortality at 30 days but not at 24 hours. Deceased patients at 30 days had higher levels of fibrinogen than those who survived (median: 2.4 vs. 1.8, p = 0.01). Patients with activated MHP had significantly higher mortality at both 24 hours and 30 days despite lack of difference in the baseline characteristics of the patients with activated MHP versus nonactivated MHP groups. The increased mortality associated with a higher RBC:FFP ratio suggests dilutional coagulopathy may contribute to mortality, but higher fibrinogen at baseline was not protective.

Triage tool for the rationing of blood for massively bleeding patients during a severe national blood shortage: guidance from the National Blood Transfusion Committee

The emerging COVID-19 pandemic has overwhelmed healthcare resources worldwide, and for transfusion services this could potentially result in rapid imbalance between supply and demand due to a severe shortage of blood donors. This may result in insufficient blood components to meet every patient's needs resulting in difficult decisions about which patients with major bleeding do and do not receive active transfusion support. This document, which was prepared on behalf of the National Blood Transfusion Committee in England, provides a framework and triage tool to guide the allocation of blood for patients with massive haemorrhage during severe blood shortage. Its goal is to provide blood transfusions in an ethical, fair, and transparent way to ensure that the greatest number of life years are saved. It is based on an evidence- and ethics-based Canadian framework, and would become operational where demand for blood greatly exceeds supply, and where all measures to manage supply and demand have been exhausted. The guidance complements existing national shortage plans for red cells and platelets.