Non-Invasive Triage for Intracranial Hypertension in Prehospital Care

Overview

This study tests whether two non-invasive tools can help paramedics detect dangerously high pressure inside the skull in patients with a sudden brain injury, such as stroke or head trauma, before they reach the hospital. The tools are a wearable sensor called Brain4care, placed on the head, and an ultrasound measurement of the eye's optic nerve. Neither tool requires needles, incisions, or any invasive procedure. The study has two parts. In the first part, researchers will use both tools on patients treated by the Mobile Emergency Care Service (SAMU) in Salvador, Brazil, to check how accurately the tools can detect high pressure inside the skull. The results from these tools will not be used to guide the patient's care during this part of the study. In the second part, some patients will be assessed using these tools as part of their emergency care, while other patients will receive standard emergency care. Researchers will compare how often each group of patients is correctly sent to a hospital with the specialized brain surgery services they may need. The goal of this research is to help emergency teams identify patients with dangerous brain pressure earlier and get them to the right hospital faster, which may improve their chances of recovery.

Acute brain injuries, including hemorrhagic and ischemic stroke and traumatic brain injury, are leading causes of death and disability worldwide and in Brazil. A common and dangerous complication of these injuries is intracranial hypertension (elevated pressure inside the skull), which can cause irreversible brain damage if not identified and treated promptly. Currently, there is no reliable, non-invasive method to assess intracranial pressure in the prehospital setting, which can delay referral to hospitals with neurosurgical capability. This study evaluates two non-invasive technologies for prehospital triage: the Brain4care (B4C) device, a wearable extensometer that detects micrometric skull deformations associated with intracranial pressure fluctuations, and ultrasound measurement of the optic nerve sheath diameter (ONSD), which correlates with intracranial pressure. The study is conducted in two sequential phases by the Mobile Emergency Care Service (SAMU) in the metropolitan area of Salvador, Brazil. Phase 1 is a prospective, blinded, observational proof-of-concept study in adult patients with suspected acute brain injury (stroke or moderate/severe traumatic brain injury). Both B4C and ONSD will be applied to all eligible patients, but results will not be used for clinical decision-making. Investigators interpreting reference-standard neuroimaging or invasive intracranial pressure monitoring will be blinded to the B4C and ONSD results. This phase will assess the diagnostic accuracy and operational feasibility of both methods in the prehospital environment. Phase 2 is an open-label, randomized, controlled, parallel-group clinical trial. Eligible patients will be randomized to standard prehospital care (control group) or prehospital triage assisted by B4C and ONSD (intervention group). The primary outcome is the proportion of patients correctly referred to hospitals with neurosurgical capability. Secondary outcomes include time to neurosurgical intervention, 30-day mortality, 90-day functional outcome, length of hospital stay, adverse events, and cost-effectiveness. This project was approved by the Research Ethics Committee of the Gonçalo Moniz Research Center - Fiocruz Bahia (CEP Opinion No. 8,050,683).