title: Entropy as an indicator of cerebral perfusion in patients with increased intracranial pressure.
abstract: Changes in electroencephalogram (EEG) patterns correlate well with changes in cerebral perfusion pressure (CPP) and hence entropy and bispectral index values may also correlate with CPP. To highlight the potential application of entropy, an EEG-based anesthetic depth monitor, on indicating cerebral perfusion in patients with increased intracranial pressure (ICP), we report two cases of emergency neurosurgical procedure in patients with raised ICP where anesthesia was titrated to entropy values and the entropy values suddenly increased after cranial decompression, reflecting the increase in CPP. Maintaining systemic blood pressure in order to maintain the CPP is the anesthetic goal while managing patients with raised ICP. EEG-based anesthetic depth monitors may hold valuable information on guiding anesthetic management in patients with decreased CPP for better neurological outcome.
authors.affiliation: Department of Anesthesia and Pain, Toronto Western Hospital, University Health Network, University of Toronto, Toronto ON, Canada.
authors.forename: James
authors.initials: J
authors.lastname: Khan
authors.affiliation: Department of Anesthesia and Pain, Toronto Western Hospital, University Health Network, University of Toronto, Toronto ON, Canada.
authors.forename: Ramamani
authors.initials: R
authors.lastname: Mariappan
authors.affiliation: Department of Anesthesia and Pain, Toronto Western Hospital, University Health Network, University of Toronto, Toronto ON, Canada.
authors.forename: Lashmi
authors.initials: L
authors.lastname: Venkatraghavan
keywords: Cerebral perfusion pressure; electroencephaogram; increased intracranial pressure; response entropy; state entropy