Errors and Consequences of Inaccurate Estimation of Mean Blood Flow Velocity in Cerebral Arteries.

Autor: Czigler A; Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK. czigler.andras@gmail.com.; Department of Neurosurgery and Szentagothai Research Center, University of Pécs, Medical School, Pécs, Hungary. czigler.andras@gmail.com.; Institute for Translational Medicine, University of Pécs, Medical School, Pécs, Hungary. czigler.andras@gmail.com., Fedriga M; Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK.; Department of Anesthesia, Critical Care and Emergency, Spedali Civili University Hospital, Brescia, Italy., Beqiri E; Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK.; Department of Physiology and Transplantation, Milan University, Milan, Italy., Lalou AD; Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK., Calviello LA; Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK., Cabeleira M; Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK., Toth P; Department of Neurosurgery and Szentagothai Research Center, University of Pécs, Medical School, Pécs, Hungary.; Institute for Translational Medicine, University of Pécs, Medical School, Pécs, Hungary.; Reynolds Oklahoma Center on Aging, Donald W. Reynolds Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA., Smielewski P; Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK., Czosnyka M; Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK.
Jazyk: angličtina
Zdroj: Acta neurochirurgica. Supplement [Acta Neurochir Suppl] 2021; Vol. 131, pp. 23-25.
DOI: 10.1007/978-3-030-59436-7_5
Abstrakt: Many transcranial Doppler ultrasonography devices estimate the mean flow velocity (FVm) by using the traditional formula (FVsystolic + 2 × FVdiastolic)/3 instead of a more accurate formula calculating it as the time integral of the current flow velocities divided by the integration period. We retrospectively analyzed flow velocity and intracranial pressure signals containing plateau waves (transient intracranial hypertension), which were collected from 14 patients with a traumatic brain injury. The differences in FVm and its derivative pulsatility index (PI) calculated with the two different methods were determined. We found that during plateau waves, when the intracranial pressure (ICP) rose, the error in FVm and PI increased significantly from the baseline to the plateau (from 4.6 ± 2.4 to 9.8 ± 4.9 cm/s, P < 0.05). Similarly, the error in PI also increased during plateau waves (from 0.11 ± 0.07 to 0.44 ± 0.24, P < 0.005). These effects were most likely due to changes in the pulse waveform during increased ICP, which alter the relationship between systolic, diastolic, and mean flow velocities. If a change in the mean ICP is expected, then calculation of FVm with the traditional formula is not recommended.
Databáze: MEDLINE