Potentially avoidable blood transfusion during trauma resuscitation

Blood lactate after pre-hospital blood transfusion for major trauma by helicopter emergency medical services

BACKGROUND AND OBJECTIVES

The appropriate use of blood components is essential for ethical use of a precious, donated product. The aim of this study was to report in-hospital red blood cell (RBC) transfusion after pre-hospital transfusion by helicopter emergency medical service paramedics. A secondary aim was to assess the potential for venous blood lactate to predict ongoing transfusion.

MATERIALS AND METHODS

All patients who received RBC in air ambulance were transported to a single adult major trauma centre, had venous blood lactate measured on arrival and did not die before ability to transfuse RBC were included. The association of venous blood lactate with ongoing RBC transfusion was assessed using multi-variable logistic regression analysis and reported using adjusted odds ratios (aOR). The discriminative ability of venous blood lactate was assessed using area under receiver operating characteristics curve (AUROC).

RESULTS

From 1 January 2016 to 15 May 2019, there were 165 eligible patients, and 128 patients were included. In-hospital transfusion occurred in 97 (75.8%) of patients. Blood lactate was associated with ongoing RBC transfusion (aOR: 2.00; 95% confidence interval [CI]: 1.36-2.94). Blood lactate provided acceptable discriminative ability for ongoing transfusion (AUROC: 0.78; 95% CI: 0.70-0.86).

CONCLUSIONS

After excluding patients with early deaths, a quarter of those who had prehospital RBC transfusion had no further transfusion in hospital. Venous blood lactate appears to provide value in identifying such patients. Lactate levels after pre-hospital transfusion could be used as a biomarker for transfusion requirement after trauma.

Overtransfusion of packed red blood cells during massive transfusion activation: a potential quality metric for trauma resuscitation

Objectives

The goal of this study was to explore the incidence of overtransfusion in trauma patients requiring massive transfusion protocol (MTP) activation and identify modifiable risk factors. We hypothesized that overtransfusion is common after MTP activation.

Methods

Patients admitted to a level I trauma center from July 2016 to December 2019 and who required MTP activation were selected. The primary outcome was overtransfusion, defined as a hemoglobin (Hg) ≥11 g/dL at 24 hours (±2 hours). A Cox regression model was used to identify independent risk factors for overtransfusion.

Results

140 patients met inclusion criteria. The median age was 39.0 years, with the majority (74.3%) being male. The median (IQR) Injury Severity Score (ISS) was 24.0 (58.0) and 38.4% had a penetrating mechanism. The median (IQR) admission Hg was 12.6 (11.7) g/dL. Overall, 71.4% of patients were overtransfused by the conclusion of MTP, 43.6% 24 hours later, and 29.5% at discharge. Overtransfusion did not correlate with the number of units of blood transfused nor with the duration of MTP. Overtransfused patients at 24 hours after the conclusion of MTP were significantly more likely to present with a penetrating injury (52.5% vs. 27.3%, p=0.003) and have a significantly lower ISS (median (IQR) 18.5 (44.0) vs. 26.0 (58.0), p=0.035.) In a Cox regression model, penetrating mechanism (adjusted HR (AHR): 2.93; adjusted p=0.004) and admission base excess (BE) (AHR: 1.15; adjusted p=0.001) were the only variables independently associated with overtransfusion.

Conclusions

Overtransfusion of trauma patients requiring MTP activation is highly common, leading to overutilization of a limited resource. Penetrating trauma and BE may be modifiable risk factors that can help limit overtransfusion. Overtransfusion should be tracked as a data point by blood banks and trauma centers and be further studied as a potential quality metric for the resuscitation of massively transfused trauma patients.

Level of evidence

III.

Prehospital Lactate is Associated with the Need for Blood in Trauma

Background: Traumatic hemorrhage is the leading cause of preventable death, and its effects are often evident within the first 24 hours of hospital admission. We investigated the relationship between prehospital lactate measurement and administration of hospital blood products and life-saving interventions (LSIs) within 24 hours of hospital admission.Methods: We included trauma patients with recorded prehospital venous lactate transported by a single critical care transport service to a Level I trauma center between 2012 and 2019. We abstracted vital signs, mission type, anatomic location of injury, prehospital administration of crystalloid and blood products, and hospital LSIs started within 24 hours of admission. We used logistic regression to determine the association of prehospital lactate and in-hospital administration of blood products in groups with or without hypotensive patients. We investigated the effect of prehospital lactate concentration on secondary outcomes such as LSIs and mortality.Results: We included 2,170 patients transported from the scene or emergency department (ED), of whom 1,821 (84%) were normotensive. The median concentration of prehospital lactate was 2.10 mmol/L for the main population (IQR = 1.40-3.30) and 2.00 mmol/L for the normotensive subgroup (IQR = 1.30-2.90). A higher prehospital lactate concentration was associated with higher odds of needing early hospital blood products in the whole study population (OR = 1.12, (95% CI 1.06-1.20), p < 0.01) and in the normotensive subgroup (OR = 1.13, (95% CI 1.03-1.22), p = 0.01). These positive associations were also observed with the secondary outcome of hospital LSIs, and higher prehospital lactate was also associated with higher odds of mortality (OR = 1.32, (95% CI 1.20-1.45), p < 0.01).Conclusions: Higher concentrations of prehospital lactate were associated with the need for in-hospital blood transfusion within 24 hours of admission. The relationship between lactate and blood transfusion persisted among normotensive patients. Further work is needed to incorporate prehospital lactate into decision support tools for prehospital blood administration.

The epidemiology of overtransfusion of red cells in trauma resuscitation patients in the context of a mature massive transfusion protocol

Purpose

Packed red blood cell (PRBC) transfusion remains an integral part of trauma resuscitation and an independent predictor of unfavourable outcomes. It is often administered urgently based on clinical judgement. These facts put trauma patients at high risk of potentially dangerous overtransfusion. We hypothesised that trauma patients are frequently overtransfused and overtransfusion is associated with worse outcomes.

Methods

Trauma patients who received PRBCs within 24 h of admission were identified from the trauma registry during the period January 1 2011–December 31 2018. Overtransfusion was defined as haemoglobin concentration of greater than or equal to 110 g/L at 24 h post ED arrival (± 12 h). Demographics, injury severity, injury pattern, shock severity, blood gas values and outcomes were compared between overtransfused and non-overtransfused patients.

Results

From the 211 patients (mean age 45 years, 71% male, ISS 27, mortality 12%) who met inclusion criteria 27% (56/211) were overtransfused. Patients with a higher pre-hospital systolic blood pressure (112 vs 99 mmHg p < 0.01) and a higher initial haemoglobin concentration (132 vs 124 p = 0.02) were more likely to be overtransfused. Overtransfused patients received smaller volumes of packed red blood cells (5 vs 7 units p = 0.049), fresh frozen plasma (4 vs 6 units p < 0.01) and cryoprecipitate (6 vs 9 units p = 0.01) than non-overtransfused patients.

Conclusion

More than a quarter of patients in our cohort were potentially given more blood products than required without obvious clinical consequences. There were no clinically relevant associations with overtransfusion.

Fractures of the femur and blood transfusions

BACKGROUND

Blood loss estimation after trauma (i.e. physical injury) and early identification of potential sources of bleeding are important for planning of investigation and management of trauma. Long bone fractures have been reported to be associated with substantial volumes of blood loss requiring blood transfusion. The aim of this study was to assess rates and amounts of blood transfusion in the setting of isolated extra capsular femur fractures and to determine variables associated with the need for transfusion within the first 48 h of admission.

METHODS

A retrospective cohort study was conducted of patients in The Alfred Trauma Registry with isolated extra capsular femur fractures over a 7-year period. We compared patients with a femoral shaft fracture (FSF) to patients with either distal femur or proximal femur fractures (i.e. extremity fracture). We collected data potentially associated with blood transfusion within 48 h as well as operation details and patient outcomes.

RESULTS

There were 293 patients included, of which 121 had FSF and 172 extremity fracture. 105 (36%) patients received a blood transfusion during their admission. Admission haemoglobin (AOR 0.92; 95%CI 0.89-0.94, p < 0.01) was the only independently associated variable with blood transfusion within the first 48 h of hospital admission.

CONCLUSION

Volume of blood transfused to patients with extra-capsular femoral fractures was low and usually in the post-operative period. FSF, compared to femoral extremity fractures, were not more likely to receive blood transfusion within the first 48 h of admission, and did not receive a higher volume of blood overall. In the setting of major trauma with haemorrhagic shock, alternate sources of bleeding should be sought.

A Derivation and Validation Study of an Early Blood Transfusion Needs Score for Severe Trauma Patients

Background

There is no existing adequate blood transfusion needs determination tool that Emergency Medical Services (EMS) personnel can use for prehospital blood transfusion initiation. In this study, a simple and pragmatic prehospital blood transfusion needs scoring system was derived and validated.

Methods

Local trauma registry data were reviewed retrospectively from 2004 through 2013. Patients were randomly assigned to derivation and validation cohorts. Multivariate logistic regression was used to identify the independent approachable risks associated with early blood transfusion needs in the derivation cohort in which a scoring system was derived. Sensitivity, specificity, and area under the receiver operational characteristic (AUC) were calculated and compared using both the derivation and validation data.

Results

A total of 24,303 patients were included with 12,151 patients in the derivation and 12,152 patients in the validation cohorts. Age, penetrating injury, heart rate, systolic blood pressure, and Glasgow coma scale (GCS) were risks predictive of early blood transfusion needs. An early blood transfusion needs score was derived. A score > 5 indicated risk of early blood transfusion need with a sensitivity of 83% and a specificity of 80%. A sensitivity of 82% and a specificity of 80% were also found in the validation study and their AUC showed no statistically significant difference (AUC of the derivation = 0.87 versus AUC of the validation = 0.86, P > 0.05).

Conclusions

An early blood transfusion scoring system was derived and internally validated to predict severe trauma patients requiring blood transfusion during prehospital or initial emergency department resuscitation.

Paediatric trauma resuscitation: an update

Purpose

Paediatric trauma is the leading cause of mortality in children. Paediatric trauma resuscitation is the first and foremost step towards a successful treatment and subsequent recovery. Significant advances have taken place in the last years in relation to this field of trauma care.

Methods

In this narrative review, we attempt to summarise the recent development in the concepts of fluid resuscitation, massive transfusion, permissive resuscitation, management of coagulopathy and use of tranexamic acid, literature pertaining to implementation of transfusion protocols in the paediatric population and education related to the paediatric trauma resuscitation.

Results/Conclusions

The current evidence although emerging is still sparse and high-quality studies are needed to shed more light on most of the above domains of resuscitation.

Indications for blood transfusion following trauma - a pilot study

Background: Indications for blood transfusion during trauma resuscitation remain poorly understood. This study aimed to objectively determine the range of factors that lead to initiation of blood transfusion during trauma resuscitation. Design and method: This was a prospective, observational pilot study. A questionnaire was distributed to all clinicians following any transfusion of packed red blood cells during trauma resuscitation. The questionnaire focused on the clinicians’ opinion regarding the indication for red cell transfusion. Results: Complete data on 37 individual episodes of transfusion initiation in the Emergency Department were collected. The most commonly used pre-hospital factors that influenced initiation of transfusion was a pre-hospital systolic blood pressure (SBP) of < 100 mm Hg (65%), pre-hospital tachycardia (38%) or estimated blood loss of >1 L (30%) by paramedics. On arrival to hospital, the activation of a massive transfusion protocol was the commonest indication for transfusion, followed by a positive FAST examination (43%), low systolic blood pressure (35%), tachycardia (32%) or pallor (35%). Blood tests to guide initiation of transfusion were less commonly used with 9 (24%) patients transfused for a low haemoglobin level and 6 (16%) patients transfused for coagulopathy. Conclusions: A combination of objective pre- and in-hospital vital signs, together with subjective indicators such as pallor and estimation of blood loss guided initiation of transfusion following injury.