Validation of the BATT score for prehospital risk stratification of traumatic haemorrhagic death: Usefulness for tranexamic acid treatment criteria.

Abstract

Background: Tranexamic acid reduces surgical blood loss and reduces deaths from bleeding in trauma patients. Tranexamic acid must be given urgently, preferably by paramedics at the scene of the injury or in the ambulance. We developed a simple score (Bleeding Audit Triage Trauma score) to predict death from bleeding.Methods: We conducted an external validation of the BATT score using data from the UK Trauma Audit Research Network (TARN) from 1st January 2017 to 31st December 2018. We evaluated the impact of tranexamic acid treatment thresholds in trauma patients.Results: We included 104,862 trauma patients with an injury severity score of 9 or above. Tranexamic acid was administered to 9,915 (9%) patients. Of these 5,185 (52%) received prehospital tranexamic acid. The BATT score had good accuracy (Brier score=6%) and good discrimination (C-statistic 0.90; 95% CI 0.89-0.91). Calibration in the large showed no substantial difference between predicted and observed death due to bleeding (1.15% versus 1.16%; P=0.81). Pre-hospital tranexamic acid treatment of trauma patients with a BATT score of 2 or more would avoid 210 bleeding deaths by treating 61,598 patients instead of avoiding 55 deaths by treating 9,915 as currently. Conclusion: The BATT score identifies trauma patient at risk of significant haemorrhage. A score of 2 or more would be an appropriate threshold for pre-hospital tranexamic acid treatment.

Use of tranexamic acid in major trauma: a sex-disaggregated analysis of the Clinical Randomisation of an Antifibrinolytic in Significant Haemorrhage (CRASH-2 and CRASH-3) trials and UK trauma registry (Trauma and Audit Research Network) data

“…14 The BATT score was externally validated in the TARN registry. 15 The score includes variables used for initial assessment (vital signs, level of consciousness, mechanism of injury, and age) that are available at the scene of injury. Although the predominant injury mechanisms are different in women and men, we did not control for mechanism of injury as it is already included in the BATT score and this could lead to over-adjustment bias (Supplementary Appendix 1).…”

“…The strengths and weaknesses of the BATT score are discussed in the external validation study. 15 The TARN registry had missing values for prehospital physiological variables, for time of injury, and for receipt of TXA. For this reason, we imputed missing values, assuming that they were missing at random.…”

“…29 Standardising clinical practice through decision support tools (such as the BATT score) without reliance on the clinical gestalt may improve care. 15 In UK prehospital care, ensuring that PGD reflect the scope of delivery supported by the evidence base and enabling use of tranexamic acid outside of patient group directions through Schedule 16 and 17 classification may result in more equitable delivery. 21 Future research should examine why women less frequently received treatment and study the effectiveness of interventions to improve equity in trauma care.…”

Recommendations from the ICM-VTE: Trauma

“…Presenting vitals/labsShock index - (HR/SBP > 0.8) an independent predictor of transfusion and mortality 94 .HISS score uses presenting labs of glucose, lactate, pH, potassium, pO2 to predict mortality and ICU stay 97 .Overall injury burden/injury severity scoreDisplaced pelvic fracture, positive FAST, increased ISS → increased risk of needing massive transfusion 102 .BATT score to predict hemorrhagic death: age, GCS, mechanism of injury, vital signs 98 . The prediction of acute coagulopathy of trauma (PACT) score used similar variables 93 .Mechanism of injuryBlunt trauma with shock associated with increased risk of bleeding.…”

“…However, Schroll et al, found ABC score to have lower sensitivity but greater specificity than shock index for predicting massive transfusion 101 . Further systems include the bleeding audit for trauma & triage (BATT) score, developed to predict hemorrhagic death in trauma, which uses SBP < 100, BP > 100, as well as respiratory rate, the Glasgow coma scale (GCS) score, age, penetrating mechanism, and high velocity trauma 98 . The head injury severity score (HISS) uses presenting labs of glucose, lactate, pH, potassium, and pO 2 to predict mortality and intensive care unit (ICU) stay 97 .…”