Abstract

Background: Hemorrhage is a leading cause of preventable mortality from trauma, necessitating resuscitation through blood product transfusions. Early and accurate identification of patients requiring transfusions in the prehospital setting may reduce delays in time to transfusion upon arrival to hospital, reducing mortality. The purpose of this study is to characterize existing literature on predictors of transfusion and analyze their utility in the prehospital context.Objectives: The objectives of this study are to characterize the existing quantity and quality of literature regarding predictor scores for transfusion in injured patients, and to analyse the utility of predictor scores for massive transfusions in the prehospital setting and identify prehospital predictor scores for future research.Methods: A search strategy was developed in consultation with information specialists. A literature search of OVID MEDLINE from 1946 to present was conducted for primary studies evaluating the predictive ability of scoring systems or single variables in predicting transfusion in all trauma settings.Results: Of the 5824 studies were identified, 5784 studies underwent title and abstract screening, 94 studies underwent full text review, and 72 studies were included in the final review. We identified 16 single variables and 52 scoring systems for predicting transfusion. Amongst single predictor variables, fluids administered and systolic blood pressure had the highest reported sensitivity (100%) and specificity (89%) for massive transfusion protocol (MTP) activation respectively. Amongst scoring systems for transfusion, the Shock Index and Modified Shock Index had the highest reported sensitivity (96%), while the Pre-arrival Model had the highest reported specificity (95%) for MTP activation. Overall, 20 scores were identified as being applicable to the prehospital setting, 25 scores were identified as being potentially applicable, and seven scores were identified as being not applicable.Conclusions: We identified an extensive list of predictive single variables, validated scoring systems, and derived models for massive transfusion, presented their properties, and identified those with potential utility in the prehospital setting. By further validating applicable scoring tools in the prehospital setting, we may begin to administer more timely transfusions in the trauma population.

Abstract

BACKGROUND In traumatic bleeding, transfusion practice has shifted toward higher doses of platelets and plasma transfusion. The aim of this systematic review was to investigate whether a higher platelet-to-red blood cell (RBC) transfusion ratio improves mortality without worsening organ failure when compared with a lower ratio of platelet-to-RBC. METHODS Pubmed, Medline, and Embase were screened for randomized controlled trials (RCTs) in bleeding trauma patients (age ≥16 years) receiving platelet transfusion between 1946 until October 2020. High platelet:RBC ratio was defined as being the highest ratio within an included study. Primary outcome was 24 hour mortality. Secondary outcomes were 30-day mortality, thromboembolic events, organ failure, and correction of coagulopathy. RESULTS In total five RCTs (n = 1757 patients) were included. A high platelet:RBC compared with a low platelet:RBC ratio significantly improved 24 hour mortality (odds ratio [OR] 0.69 [0.53-0.89]) and 30- day mortality (OR 0.78 [0.63-0.98]). There was no difference between platelet:RBC ratio groups in thromboembolic events and organ failure. Correction of coagulopathy was reported in five studies, in which platelet dose had no impact on trauma-induced coagulopathy. CONCLUSIONS In traumatic bleeding, a high platelet:RBC improves mortality as compared to low platelet:RBC ratio. The high platelet:RBC ratio does not influence thromboembolic or organ failure event rates.

Abstract

BACKGROUND Trial outcomes should be relevant to all stakeholders, and allow assessment of interventions' efficacy and safety at appropriate timeframes. There is no consensus regarding outcome measures in the growing field of pre-hospital trauma transfusion research. Harmonization of future clinical outcome reporting is key to facilitate inter-study comparisons and generate cohesive, robust evidence to guide practice. OBJECTIVES To evaluate outcome measures reported in pre-hospital trauma transfusion trials. METHODS Data Sources, Eligibility Criteria, Participants and InterventionsWe conducted a scoping systematic review to identify the type, number and definitions of outcomes reported in randomised controlled trials, prospective and retrospective observational cohort studies investigating pre-hospital blood component transfusion in adult and paediatric patients with traumatic haemorrhage. Electronic database searching of PubMed, Embase, Web of Science, Cochrane, OVID, clinical trials.gov, and the Transfusion Evidence Library was completed in accordance with PRISMA guidelines.Study Appraisal and Synthesis MethodsTwo review authors independently extracted outcome data. Unique lists of salutogenic (patient-reported health and wellbeing outcomes) and non-salutogenic focused outcomes were established. RESULTS 3,471 records were identified. 34 studies fulfilled inclusion criteria: four military (n = 1,566 patients) and 30 civilian (n = 14,398 patients), all between 2000 and 2020. 212 individual non-patient-reported outcomes were identified, which collapsed into 20 outcome domains with varied definitions and timings. All primary outcomes measured effectiveness, rather than safety or complications. 69% reported mortality, with 11 different definitions. No salutogenic outcomes were reported. LIMITATIONS The review is limited by a lack of high-grade prospective comparative trials with clear predefined primary outcomes. CONCLUSION AND IMPLICATIONS OF KEY FINDINGS There is heterogeneity in outcome reporting and definitions, an absence of patient-reported outcome, and an emphasis on clinical effectiveness rather than safety or adverse events in pre-hospital trauma transfusion trials. We recommend stakeholder consultation and a Delphi process to develop a clearly defined minimum core outcome set for pre-hospital trauma transfusion trials. SYSTEMATIC REVIEW REGISTRATION NUMBER This review was prospectively registered with PROSPERO (CRD42019131406). LEVEL OF EVIDENCE II. STUDY TYPE Scoping Systematic Review.

Abstract

Early diagnosis of haemorrhagic shock (HS) might be difficult because of compensatory mechanisms. Clinical scoring systems aimed at predicting transfusion needs might assist in early identification of patients with HS. The Shock Index (SI) - defined as heart rate divided by systolic BP - has been proposed as a simple tool to identify patients with HS. This systematic review discusses the SI's utility post-trauma in predicting critical bleeding (CB). We searched the databases MEDLINE, Embase, CINAHL, Cochrane Library, Scopus and PubMed from their commencement to 1 September 2013. Studies that described an association with SI and CB, defined as at least 4 units of packed red blood cells (pRBC) or whole blood within 24h, were included. Of the 351 located articles identified by the initial search strategy, five met inclusion criteria. One study pertained to the pre-hospital setting, one to the military, two to the in-hospital setting, and one included analysis of both pre-hospital and in-hospital values. The majority of papers assessed predictive properties of the SI in >10 units pRBC in the first 24h. The most frequently suggested optimal SI cut-off was >0.9. An association between higher SI and bleeding was demonstrated in all studies. The SI is a readily available tool and may be useful in predicting CB on arrival to hospital. The evaluation of improved utility of the SI by performing and recording at earlier time-points, including the pre-hospital phase, is indicated. 2014 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine.