SGEM#305: Somebody Get Me A Doctor – But Do I Need TXA by EMS for a TBI?

Date: October 14th, 2020 Guest Skeptic: Dr.Salim Rezaie is a community emergency physician at Greater San Antonio Emergency Physicians (GSEP), where he is the director of clinical education.  Salim is probably better known as the creator and founder of the wonderful knowledge translation project called REBEL EM. It is a free, critical appraisal blog and podcast that try to cut down knowledge translation gaps of research to bedside clinical practice. Reference: Rowell et al. Effect of Out-of-Hospital Tranexamic Acid vs Placebo on 6-Month Functional Neurologic Outcomes in Patients With Moderate or Severe Traumatic Brain Injury. JAMA 2020.  Case: A 42-year-old helmeted bicycle rider is involved in an accident where he hits his head on the ground.  At the time of emergency medical services (EMS) arrival, the patient is alert but seems a bit confused.  The accident was within one hour of injury and his Glasgow Coma Scale (GSC) score was 12. Vital signs show a slight tachycardia but otherwise normal. Pupils were both equal and reactive and he doesn’t appear to have any other traumatic injuries, or focal neurologic deficits. Other injuries appear minimal with some abrasions from the fall. Background: The CRASH-2 trial, published in 2010, showed a 1.5% mortality benefit (NNT 67) for patients with traumatic hemorrhage who received tranexamic acid (TXA) compared to placebo. Dr. Anand Swaminathan and I covered that classic paper on SGEM#80. TXA has become standard practice in many settings as a result of this data.  However, patients with significant head injury were excluded in this study and it was unclear of the effect of TXA in this group. CRASH-3 Fast forward to October 2019, when CRASH-3 was published. This large, very well-done randomized placebo-controlled trial examined the use of TXA in patients with traumatic brain injuries (TBIs) with GCS score of 12 or lower or any intracranial bleed on CT scan and no extracranial bleeding treated within 3 hours of injury. The authors reported no statistical superiority of TXA compared to placebo for the primary outcome of head injury-related deaths within 28 days. We reviewed that article published in the Lancet in SGEM#270. Subgroup analysis did demonstrate that certain patients (GCS 9 to 15 and ICH on baseline CT) showed a mortality benefit with TXA. While very interesting and potentially clinically significant, we need to be careful not to over-interpret this subgroup analysis. We did express concern over the possibility that this subgroup would be highlighted and “spun”. Unfortunately, that did happen with a subsequent media blitz and a misleading infographic. Further data is clearly needed to elucidate the role of TXA in patients with TBI. Clinical Question: Does pre-hospital administration of TXA to patients with moderate or severe traumatic brain injury improve neurologic outcomes at 6 months? Reference: Rowell et al. Effect of Out-of-Hospital Tranexamic Acid vs Placebo on 6-Month Functional Neurologic Outcomes in Patients With Moderate or Severe Traumatic Brain Injury. JAMA 2020. Population: Patients 15 years of age or older with moderate or severe blunt or penetrating TBI. Moderate to severe TBI was defined as a GCS 3 to 12, at least one reactive pupil, systolic blood pressure ≥90mmHg prior to randomization, able to receive intervention or placebo within two hours from injury, and destination to a participating trauma center. Exclusions: Prehospital GCS=3 with no reactive pupil, start of study drug bolus dose greater than two hours from injury, unknown time of injury, clinical suspicion by EMS of seizure activity, acute MI or stroke, or known history, of seizures, thromboembolic disorders or renal dialysis, CPR by EMS prior to randomization, burns > 20% total body surface area, suspected or known prisoners, suspected or known pregnancy), prehospital TXA or other pro-coagulant drug given prior to randomization or subjects who hav...