Pressure-targeted neurocritical care at the bedside: the emerging role of transcranial doppler

Management of acute brain injury (ABI) focuses on maintaining cerebral perfusion pressure through systemic blood pressure optimization. However, traditional approaches relying on fixed pressure thresholds may not fully capture the complex interaction between systemic hemodynamics, cerebrovascular resistance, and cerebral autoregulation. Transcranial Doppler (TCD) ultrasonography offers a noninvasive bedside method to assess cerebral blood flow velocity patterns and their response to hemodynamic interventions. Doppler-derived parameters such as diastolic flow velocity (FVd) and pulsatility index (PI) provide physiological information that may help interpret the relationship between systemic arterial pressure and cerebral circulation. Observing how these signals change during controlled adjustments of mean arterial pressure may allow clinicians to identify pressure ranges in which cerebral perfusion appears more favorable for an individual patient. Importantly, TCD findings should not be interpreted in isolation but integrated with systemic hemodynamic assessment, including cardiac output, fluid responsiveness, and the underlying mechanism of hypotension. When used within a multimodal monitoring strategy, TCD may serve as a practical physiological tool to complement traditional neurocritical care monitoring. This viewpoint discusses the physiological rationale, potential clinical applications, and current limitations of Doppler-guided blood pressure targeting in patients with ABI.