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.

Handling of Missing Outcome Data in Traumatic Brain Injury Research: A Systematic Review

“…Search terms relating to traumatic brain injury were taken from a previously published living review by the CENTER-TBI group 11 and included exploded MESH terms for ''Brain Injuries'' or ''Craniocerebral Trauma'' or word variations of ''((head* or brain*) adj2 (injur* or trauma*))'' in the title, abstract, or keywords. 12 These were combined with the following search terms relating to the Glasgow Outcome Scale (GOS): the exploded MESH term for ''Glasgow Outcome Scale''; or word variations of ''(Glasgow Outcome Scale or extended Glasgow Outcome Scale or GOS or GOSE)'' or ''((functional or neur*) adj (status or outcome*))'' in the title, abstract, or key words. The search was restricted to studies on human participants.…”

Aspects on the Physiological and Biochemical Foundations of Neurocritical Care

“…It has been suggested that PRx could be used for targeting the optimal CPP (71, 72) but currently the evidence is not sufficient to make recommendations for implementing this strategy (72). Furthermore, in patients with subarachnoid hemorrhage (SAH), the interpretation of PRx was ambiguous when compared to simultaneous measures of CBF, and it was concluded that PRx was not a reliable indicator of the status of autoregulation (69).…”

Unraveling the complexities of invasive multimodality neuromonitoring

“…Persistently positive PRx is associated with poor outcome, 14,75 and maintaining CPP in a range where PRx is minimized (i.e., CPP opt ) may improve outcome. 1,42,57 The PRx fluctuations can be plotted along with other trends in multimodal data displays (Fig. 2), allowing the effects of different therapies on the autoregulatory state to be assessed.…”