Objectives: Optimal cerebral perfusion pressure (CPPopt) is a concept that uses the pressure reactivity (PRx)-CPP relationship over a given period to find a value of CPP at which PRx shows best autoregulation. It has been proposed that this relationship be modelled by a U-shaped curve, where the minimum is interpreted as being the CPP value that corresponds to the strongest autoregulation. Owing to the nature of the calculation and the signals involved in it, the occurrence of CPPopt curves generated by non-physiological variations of intracranial pressure (ICP) and arterial blood pressure (ABP), termed here "false positives", is possible. Such random occurrences would artificially increase the yield of CPPopt values and decrease the reliability of the methodology.In this work, we studied the probability of the random occurrence of false-positives and we compared the effect of the parameters used for CPPopt calculation on this probability.
Materials And Methods: To simulate the occurrence of false-positives, uncorrelated ICP and ABP time series were generated by destroying the relationship between the waves in real recordings. The CPPopt algorithm was then applied to these new series and the number of false-positives was counted for different values of the algorithm's parameters.
Results: The percentage of CPPopt curves generated from uncorrelated data was demonstrated to be 11.5%.
Conclusion: This value can be minimised by tuning some of the calculation parameters, such as increasing the calculation window and increasing the minimum PRx span accepted on the curve.
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http://dx.doi.org/10.1007/978-3-319-65798-1_30 | DOI Listing |
Neurocrit Care
December 2024
Brain Physics Laboratory, Department of Clinical Neurosciences, Division of Neurosurgery, University of Cambridge, Cambridge, UK.
Curr Opin Crit Care
April 2022
Department of Intensive Care.
Purpose Of Review: Individualizing cerebral perfusion pressure based on cerebrovascular autoregulation assessment is a promising concept for neurological injuries where autoregulation is typically impaired. The purpose of this review is to describe the status quo of autoregulation-guided protocols and discuss steps towards clinical use.
Recent Findings: Retrospective studies have indicated an association of impaired autoregulation and poor clinical outcome in traumatic brain injury (TBI), hypoxic-ischemic brain injury (HIBI) and aneurysmal subarachnoid hemorrhage (aSAH).
J Neurotrauma
October 2021
Department of Intensive Care Medicine, University Maastricht (KEMTA), Maastricht University Medical Center+, Maastricht, The Netherlands.
Managing traumatic brain injury (TBI) patients with a cerebral perfusion pressure (CPP) near to the cerebral autoregulation (CA)-guided "optimal" CPP (CPPopt) value is associated with improved outcome and might be useful to individualize care, but has never been prospectively evaluated. This study evaluated the feasibility and safety of CA-guided CPP management in TBI patients requiring intracranial pressure monitoring and therapy (TBIicp patients). The CPPopt Guided Therapy: Assessment of Target Effectiveness (COGiTATE) parallel two-arm feasibility trial took place in four tertiary centers.
View Article and Find Full Text PDFJ Neurotrauma
January 2020
Department of Neurosurgery, University Hospital Heidelberg, Heidelberg, Germany.
Identification of individual therapy targets is critical for traumatic brain injury (TBI) patients. Clinical outcomes depend on cerebrovascular autoregulation (CA) impairment. Here, we compare the effectiveness of optimal cerebral perfusion pressure (CPPopt)-targeted therapy in younger (<45 years of age) and elderly (≥45 years of age) TBI patients.
View Article and Find Full Text PDFJ Cereb Blood Flow Metab
June 2020
Department of Neurology, Columbia University College of Physicians and Surgeons, New York, NY, USA.
The association between impaired brain perfusion, cerebrovascular reactivity status and the risk of ictal events in patients with subarachnoid hemorrhage is unknown. We identified 13 subarachnoid hemorrhage (SAH) patients with seizures and 22 with ictal-interictal continuum (IIC), and compared multimodality physiological recordings to 38 similarly poor-grade SAH patients without ictal activity. We analyzed 10,179 cumulative minutes of seizure and 12,762 cumulative minutes of IIC.
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