Continuous time-domain monitoring of cerebral autoregulation in neurocritical care.
Integration of various brain signals can be used to determine cerebral autoregulation in neurocritical care patients to guide clinical management and to predict outcome. In this review, we will discuss current methodology of multimodal brain monitoring focusing on secondary 'reactivity indices' derived from various brain signals which are based on a 'moving correlation coefficient'. This algorithm was developed in order to analyze in a time dependent manner the degree of correlation between two factors within a time series where the number of paired observations is large. Of the various primary neuromonitoring sources which can be used to calculate reactivity indices, we will focus in this review on indices based on transcranial Doppler (TCD), intracranial pressure (ICP), brain tissue oxygenation (PbtO2) and near infrared spectroscopy (NIRS). Furthermore, we will demonstrate how reactivity indices can show transient changes of cerebral autoregulation and can be used to optimize management of arterial blood pressure (ABP) and cerebral perfusion pressure (CPP).
Academic Neurosurgical Unit, University of Cambridge Department of Clinical Neurosciences, Cambridge, United Kingdom; Department of Neurosurgery, University Hospital of Basel, Basel, Switzerland. Electronic address: zweifelch@gmx.ch.
Christian
C
Zweifel
Academic Neurosurgical Unit, University of Cambridge Department of Clinical Neurosciences, Cambridge, United Kingdom; Department of Critical Care, Neurocritical Care Unit, Hospital S. João, University of Porto, Portugal.
Celeste
C
Dias
Academic Neurosurgical Unit, University of Cambridge Department of Clinical Neurosciences, Cambridge, United Kingdom.
Peter
P
Smielewski
Academic Neurosurgical Unit, University of Cambridge Department of Clinical Neurosciences, Cambridge, United Kingdom.
Marek
M
Czosnyka
D001921:Brain / Q000098:blood supply / Q000378:metabolism / Q000503:physiopathology*; D002560:Cerebrovascular Circulation; D003422:Critical Care / Q000379:methods*; D006706:Homeostasis; D006801:Humans; D008991:Monitoring, Physiologic / Q000379:methods*; D009422:Nervous System Diseases / Q000503:physiopathology* / Q000628:therapy*
Cerebral autoregulation; Cerebrovascular pressure reactivity; Neurocritical care