title: Cerebral Perfusion Pressure Targets Individualized to Pressure-Reactivity Index in Moderate to Severe Traumatic Brain Injury: A Systematic Review.
abstract: Traumatic brain injury (TBI) frequently triggers a disruption of cerebral autoregulation. The cerebral perfusion pressure (CPP) at which autoregulation is optimal ("CPPopt") varies between individuals, and can be calculated based on fluctuations between arterial blood pressure and intracranial pressure. This review assesses the effect of individualizing CPP targets to pressure reactivity index (a measure of autoregulation) in patients with TBI. Cochrane Central Register of Controlled Trials, MEDLINE®, Embase, and Cumulative Index of Nursing and Allied Health Literature were searched in March 2015 for studies assessing the effect of targeting CPPopt in TBI. We included all studies that assessed the impact of targeting CPPopt on outcomes including mortality, neurological outcome, and physiological changes. Risk of bias was assessed using the RTI Item Bank and evidence quality was considered using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) criteria. Eight cohort studies (based on six distinct data sets) assessing the association between CPPopt and mortality, Glasgow Outcome Scale and physiological measures in TBI were included. The quality of evidence was deemed very low based on the GRADE criteria. Although the data suggest an association between variation from CPPopt and poor clinical outcome at 6 months, the quality of evidence prevents firm conclusions, particularly regarding causality, from being drawn. Available data suggest that targeting CPPopt might represent a technique to improve outcomes following TBI, but currently there is insufficient high-quality data to support a recommendation for use in clinical practice. Further prospective, randomized controlled studies should be undertaken to clarify its role in the acute management of TBI.
authors.affiliation: 1 Department of Neurology, Addenbrookes Hospital, University of Cambridge , Cambridge, United Kingdom .
authors.forename: Edward
authors.initials: E
authors.lastname: Needham
authors.affiliation: 2 Division of Anaesthesia, Addenbrookes Hospital, University of Cambridge , Cambridge, United Kingdom .
authors.forename: Charles
authors.initials: C
authors.lastname: McFadyen
authors.affiliation: 2 Division of Anaesthesia, Addenbrookes Hospital, University of Cambridge , Cambridge, United Kingdom .
authors.forename: Virginia
authors.initials: V
authors.lastname: Newcombe
authors.affiliation: 3 Australian & New Zealand Intensive Care Research Centre (ANZIC-RC) , School of Public Health and Preventive Medicine, Monash University, Melbourne Victoria, Australia; Cochrane Consumers and Communication Review Group, Centre for Health Communication and Participation, School of Psychology and Public Health, La Trobe University, Melbourne, Australia; National Trauma Research Institute, Melborne, Australia .
authors.forename: Anneliese J
authors.initials: AJ
authors.lastname: Synnot
authors.affiliation: 4 Brain Physics Lab, Division of Neurosurgery, Addenbrookes Hospital, University of Cambridge , Cambridge, United Kingdom .
authors.forename: Marek
authors.initials: M
authors.lastname: Czosnyka
authors.affiliation: 2 Division of Anaesthesia, Addenbrookes Hospital, University of Cambridge , Cambridge, United Kingdom .
authors.forename: David
authors.initials: D
authors.lastname: Menon
mesh_terms: D000070642:Brain Injuries, Traumatic / Q000401:mortality / Q000503:physiopathology* / Q000628:therapy*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D006706:Homeostasis / Q000502:physiology*; D006801:Humans; D017063:Outcome Assessment, Health Care
keywords: TBI; cerebral blood flow autoregulation; therapeutic approaches for the treatment of central nervous system injury; vascular reactivity