title: Autoregulation monitoring and outcome prediction in neurocritical care patients: Does one index fit all?
abstract: Indexes PRx and Mx have been formerly introduced to assess cerebral autoregulation and have been shown to be associated with 3-month clinical outcome. In a mixed cohort of neurocritical care patients, we retrospectively investigated the impact of selected clinical characteristics on this association. Forty-one patients (18-77 years) with severe traumatic (TBI, N = 20) and non-traumatic (N = 21) brain injuries were studied. Cerebral blood flow velocity, arterial blood pressure and intracranial pressure were repeatedly recorded during 1-h periods. Calculated PRx and Mx were correlated with 3-month clinical outcome score of modified Rankin Scale (mRS) in different subgroups with specific clinical characteristics. Both PRx and Mx correlated significantly with outcome (PRx: r = 0.38, p < 0.05; AUC = 0.64, n.s./Mx: r = 0.48, p < 0.005; AUC = 0.80, p < 0.005) in the overall group, and in patients with hemicraniectomy (N = 17; PRx: r = 0.73, p < 0.001; AUC = 0.89, p < 0.01/Mx: r = 0.69, p < 0.005; AUC = 0.87, p < 0.05). Mx, not PRx, correlated significantly with mRS in patients with heart failure (N = 17; r = 0.69, p < 0.005; AUC = 0.92, p < 0.005), and in non-traumatic patients (r = 0.49, p < 0.05; AUC = 0.79, p < 0.05). PRx, not Mx, correlated significantly with mRS in TBI patients (r = 0.63, p < 0.01; AUC = 0.89, p < 0.01). Both indexes did not correlate with mRS in diabetes patients (N = 15), PRx failed in hypocapnic patients (N = 26). Both PRx and Mx were significantly associated with 3-month clinical outcome, even in patients with hemicraniectomy. PRx was more appropriate for TBI patients, while Mx was better suited for non-traumatic patients and patients with heart failure. Prognostic values of indexes were affected by diabetes (both Mx and PRx) and hypocapnia (PRx only).
authors.affiliation: Department of Neurology, Chemnitz Medical Centre, Dresdner Str. 178, 09131, Chemnitz, Germany. B.Schmidt@skc.de.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Schmidt
authors.affiliation: Department of Neurology, University of Freiburg, Breisacher Str. 64, 79106, Freiburg, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Reinhard
authors.affiliation: Department of Neurology, Chemnitz Medical Centre, Dresdner Str. 178, 09131, Chemnitz, Germany.
authors.forename: Vesna
authors.initials: V
authors.lastname: Lezaic
authors.affiliation: School of Biomedical Sciences and Pharmacy, The University of Newcastle, Callaghan, NSW, 2308, Australia.
authors.forename: Damian D
authors.initials: DD
authors.lastname: McLeod
authors.affiliation: Department of Neurology, Chemnitz Medical Centre, Dresdner Str. 178, 09131, Chemnitz, Germany.
authors.forename: Marco
authors.initials: M
authors.lastname: Weinhold
authors.affiliation: Department of Electrical, Electronic and Communication Engineering, Friedrich-Alexander Universität Erlangen-Nürnberg, 91052, Erlangen, Germany.
authors.forename: Heinz
authors.initials: H
authors.lastname: Mattes
authors.affiliation: Department of Neurology, Chemnitz Medical Centre, Dresdner Str. 178, 09131, Chemnitz, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Klingelhöfer
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D062186:Arterial Pressure; D001783:Blood Flow Velocity; D001930:Brain Injuries / Q000503:physiopathology*; D000070642:Brain Injuries, Traumatic / Q000503:physiopathology; D002560:Cerebrovascular Circulation / Q000502:physiology*; D015331:Cohort Studies; D003422:Critical Care; D005260:Female; D006706:Homeostasis; D006801:Humans; D007427:Intracranial Pressure / Q000502:physiology; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods* / Q000706:statistics & numerical data; D064926:Neurophysiological Monitoring / Q000379:methods / Q000706:statistics & numerical data; D011379:Prognosis; D012189:Retrospective Studies; D017585:Ultrasonography, Doppler, Transcranial; D055815:Young Adult
keywords: Cerebral autoregulation; Cerebral blood flow; Cerebrovascular pressure reactivity; Modified Rankin Scale; Stroke; Traumatic brain injury