Trends in Traumatic Brain Injury Among U.S. Service Members Deployed in Iraq and Afghanistan, 2002-2016.

INTRODUCTION: Traumatic brain injury (TBI) is a major health issue for service members deployed and is more common in recent conflicts; however, a thorough understanding of risk factors and trends is not well described. This study aims to characterize the epidemiology of TBI in U.S. service members and the potential impacts of changes in policy, care, equipment, and tactics over the 15 years studied. METHODS: Retrospective analysis of U.S. Department of Defense Trauma Registry data (2002-2016) was performed on service members treated for TBI at Role 3 medical treatment facilities in Iraq and Afghanistan. Risk factors and trends in TBI were examined in 2021 using Joinpoint regression and logistic regression. RESULTS: Nearly one third of 29,735 injured service members (32.4%) reaching Role 3 medical treatment facilities had TBI. The majority sustained mild (75.8%), followed by moderate (11.6%) and severe (10.6%) TBI. TBI proportion was higher in males than in females (32.6% vs 25.3%; p<0.001), in Afghanistan than in Iraq (43.8% vs 25.5%; p<0.001), and in battle than in nonbattle (38.6% vs 21.9%; p<0.001). Patients with moderate or severe TBI were more likely to have polytrauma (p<0.001). TBI proportion increased over time, primarily in mild TBI (p=0.02), slightly in moderate TBI (p=0.04), and most rapidly between 2005 and 2011, with a 2.48% annual increase. CONCLUSIONS: One third of injured service members at Role 3 medical treatment facilities experienced TBI. Findings suggest that additional preventive measures may decrease TBI frequency and severity. Clinical guidelines for field management of mild TBI may reduce the burden on evacuation and hospital systems. Additional capabilities may be needed for military field hospitals.

Saving the brain after mild-to-moderate traumatic injury: A report on new insights of the physiology underlying adequate maintenance of cerebral perfusion.

ABSTRACT: Traumatic brain injury (TBI) is associated with increased morbidity and mortality in civilian trauma and battlefield settings. It has been classified across a continuum of dysfunctions, with as much as 80% to 90% of cases diagnosed as mild to moderate in combat casualties. In this report, a framework is presented that focuses on the potential benefits for acute noninvasive treatment of reduced cerebral perfusion associated with mild TBI by harnessing the natural transfer of negative intrathoracic pressure during inspiration. This process is known as intrathoracic pressure regulation (IPR) therapy, which can be applied by having a patient breath against a small inspiratory resistance created by an impedance threshold device. Intrathoracic pressure regulation therapy leverages two fundamental principles for improving blood flow to the brain: (1) greater negative intrathoracic pressure enhances venous return, cardiac output, and arterial blood pressure; and (2) lowering of intracranial pressure provides less resistance to cerebral blood flow. These two effects work together to produce a greater pressure gradient that results in an improvement in cerebral perfusion pressure. In this way, IPR therapy has the potential to counter hypotension and hypoxia, potentially significant contributing factors to secondary brain injury, particularly in conditions of multiple injuries that include severe hemorrhage. By implementing IPR therapy in patients with mild-to-moderate TBI, a potential exists to provide early neuroprotection at the point of injury and a bridge to more definitive care, particularly in settings of prolonged delays in evacuation such as those anticipated in future multidomain operations. LEVEL OF EVIDENCE: Report.