Reference: Jansen et al. Emergency Department Resuscitative Endovascular Balloon Occlusion of the Aorta in Trauma Patients With Exsanguinating Hemorrhage: The UK-REBOA Randomized Clinical Trial. JAMA. 2023 Date: June 10, 2024 Guest Skeptic: Dr. Rob Leeper is an intensivist, trauma surgeon, and general surgeon at Western University where he also serves as the director of the Royal College Surgical Foundations program. He is particularly enthusiastic about medical education and the use of high-fidelity simulation to identify latent threats to patient safety and improve team-based crisis resource management. Case: A 24-year-old patient is involved in a high-speed motor vehicle collision.  The patient was the intoxicated driver of a sport utility vehicle that left the road and collided head-on with a traffic light.  The driver was ejected from the vehicle.  On scene, he has a Glasgow Coma Scale (GCS) score of 14, is tachycardic at 130 beats per minute and hypotensive at 85/50 mmHg.  He complains of severe pain in his abdomen and left upper extremity.  He has an obvious angulated deformity of his left wrist. Pre-hospital personnel placed the patient in a cervical spine collar, obtained peripheral intravenous (IV) access, administered 250cc of 0.9% saline and provided rapid transport to the local trauma center which is less than 15 minutes away.  On arrival at the trauma center, the patient’s vital signs and symptoms remain essentially unchanged from those on scene. You initiate standard, simultaneous assessment and resuscitation following the Advanced Trauma Life Support (ATLS) principles.  You are debating the addition of resuscitative endovascular balloon occlusion of the aorta (REBOA) as an adjunct to your standard care.  You wonder what the evidence is for this additional approach. Background: We covered REBOA on the SGEM 5 years ago with Dr. Robert Edmonds (SGEM#258). That was a review of a retrospective observational study of 593,818 trauma patients of which 140 received REBOA compared to 240 matched controls who did not receive this treatment. The overall mortality was worse with REBOA (35.7% vs. 18.9%, p=0.01). The SGEM bottom line in 2019 was that REBOA is currently an intervention of uncertain benefit. Although it has shown promise in some studies, this investigation leaves its therapeutic potential in question and arguably demonstrates harm. There may be substantial benefits in select groups of trauma patients, but these groups are not yet known. Trauma surgeons are hemorrhage control surgeons.  Bleeding is the enemy and patient survival turns tenuously on our ability to identify and staunch hemorrhage in as expedient a fashion as possible.  Time is our currency and, for patients with massive hemorrhage, minutes matter.  Every strategy that enhances time to hemorrhage control is deserving of examination: Trauma Systems - Enhancing the training and tools for our pre-hospital teams, faster helicopters, more trauma centers, etc. Hemostatic Resuscitation - Permissive hypotension, whole blood and factor ratio resuscitation, warmed products, dynamic coagulation monitoring, etc. Enhanced Operative Strategies - Damage control surgery with truncated interventions, energy devices, hemostatic foams/gels/packs, etc. These approaches hold the possibility of enhancing our ability to save patient’s lives. One approach, which has seen a revival in its interest and utilization, is proximal balloon occlusion of the aorta.  The rationale is simple, occluding the aorta above the level of bleeding will de facto reduce blood loss at the site of injury and lead to immediately increased blood pressure and, presumably, perfusion to the zone above the occlusion, typically the upper body, the heart, and the brain.  A great variety of medical devices designed for this purpose have come to market over the last 15 years and a relatively heterogeneous collection of retrospective clinical data has been published with confl...