title: Plateau Waves of Intracranial Pressure and Partial Pressure of Cerebral Oxygen.
abstract: This study investigates 55 intracranial pressure (ICP) plateau waves recorded in 20 patients after severe traumatic brain injury (TBI) with a focus on a moving correlation coefficient between mean arterial pressure (ABP) and ICP, called PRx, which serves as a marker of cerebrovascular reactivity, and a moving correlation coefficient between ABP and cerebral partial pressure of oxygen (pbtO2), called ORx, which serves as a marker for cerebral oxygen reactivity. ICP and ICPamplitude increased significantly during the plateau waves, whereas CPP and pbtO2 decreased significantly. ABP, ABP amplitude, and heart rate remained unchanged. In 73 % of plateau waves PRx increased during the wave. ORx showed an increase during and a decrease after the plateau waves, which was not statistically significant. Our data show profound cerebral vasoparalysis on top of the wave and, to a lesser extent, impairment of cerebral oxygen reactivity. The different behavior of the indices may be due to the different latencies of the cerebral blood flow and oxygen level control mechanisms. While cerebrovascular reactivity is a rapidly reacting mechanism, cerebral oxygen reactivity is slower.
authors.affiliation: Neurosurgical Associates, Red Cross Hospital, Bergmannstrasse 30, Kassel, D-34121, Germany. keeflang@online.de.
authors.forename: Erhard W
authors.initials: EW
authors.lastname: Lang
authors.affiliation: Institute of Biomedical Engineering and Instrumentation, Wroclaw University of Technology, Wroclaw, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Kasprowicz
authors.affiliation: Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK.
authors.forename: Peter
authors.initials: P
authors.lastname: Smielewski
authors.affiliation: Department of Neurosurgery, Addenbrookes's Hospital, University of Cambridge, Cambridge, UK.
authors.forename: John
authors.initials: J
authors.lastname: Pickard
authors.affiliation: Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK.
authors.forename: Marek
authors.initials: M
authors.lastname: Czosnyka
mesh_terms: D062186:Arterial Pressure; D000070642:Brain Injuries, Traumatic / Q000150:complications / Q000503:physiopathology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D054022:Cerebrum / Q000378:metabolism*; D006339:Heart Rate; D006801:Humans; D019586:Intracranial Hypertension / Q000209:etiology / Q000378:metabolism* / Q000503:physiopathology; D007427:Intracranial Pressure; D010100:Oxygen / Q000378:metabolism*; D010313:Partial Pressure
chemical_list: D010100:Oxygen
keywords: Cerebral autoregulation; Cerebral hemodynamics; Cerebral oxygenation; Cerebral partial pressure of oxygen; Cerebrovascular circulation; Intracranial pressure; Traumatic brain injury