Point-of-Care Transcranial Doppler Sonography at the Intensive Care Unit—A Practical Review of the Fundamentals

Point-of-care ultrasonography (POCUS) has become an integral part of intensive and emergency care. Despite the widespread use and availability of multipurpose ultrasound devices, the regular assessment of intracranial circulatory conditions has not become a part of daily routine in multidisciplinary intensive care units. This brief narrative review aims to summarize the fundamental knowledge about the transcranial Doppler technique and the most significant clinical areas in which the method can provide valuable assistance in daily diagnostic and therapeutic decision-making. The authors searched the PubMed database for reviews, systematic reviews, and meta-analyses using the keywords "transcranial Doppler sonography; critical care; cerebral vasospasm; brain death diagnosis; non-invasive intracranial pressure monitoring". We conclude that TCD is a simple, yet skilled, bedside method for assessing intracranial circulation. In everyday practice, it can be used to support clinical decision-making primarily in the areas of intracranial pressure monitoring, diagnosis and follow-up of cerebral vasospasm, and diagnosis of cerebral circulatory arrest. The study of cerebral hemodynamics should be an integral part of the increasingly widespread bedside ultrasound diagnostics in intensive care.