Objective: An 'optimal' cerebral perfusion pressure (CPPopt) can be defined as the point on the CPP scale corresponding to the greatest autoregulatory capacity. This can be established by examining the pressure reactivity index PRx-CPP relationship, which is approximately U-shaped but suffers from noise and missing data. In this paper, we present a method for plotting the whole PRx-CPP relationship curve against time in the form of a colour-coded map depicting the 'landscape' of that relationship extending back for several hours and to display this robustly at the bedside.This is a short version of a full paper recently published in Critical Care Medicine (2016) containing some new insights and details of a novel bedside implementation based on a presentation during Intracranial Pressure 2016 Symposium in Boston.
Methods: Recordings from routine monitoring of traumatic brain injury patients were processed using ICM+. Time-averaged means for arterial blood pressure, intracranial pressure, cerebral perfusion pressure (CPP) and pressure reactivity index (PRx) were calculated and stored with time resolution of 1 min. ICM+ functions have been extended to include not just an algorithm of automatic calculation of CPPopt but also the 'CPPopt landscape' chart.
Results: Examining the 'CPPopt landscape' allows the clinician to differentiate periods where the autoregulatory range is narrow and needs to be targeted from periods when the patient is generally haemodynamically stable, allowing for more relaxed CPP management. This information would not have been conveyed using the original visualisation approaches.
Conclusions: We describe here a natural extension to the concept of autoregulatory assessment, providing the retrospective 'landscape' of the PRx-CPP relationship extending over the past several hours. We have incorporated such visualisation techniques online in ICM+. The proposed visualisation may facilitate clinical evaluation and use of autoregulation-guided therapy.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1007/978-3-319-65798-1_12 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Does Targeting CPP at CPPopt Actually Improve Cerebrovascular Reactivity? A Secondary Analysis of the COGiTATE Randomized Controlled Trial.
Neurocrit Care
December 2024
Brain Physics Laboratory, Department of Clinical Neurosciences, Division of Neurosurgery, University of Cambridge, Cambridge, UK.
Article Synopsis
- * A secondary analysis found that patients in the CPPopt-targeted group had better autoregulation, indicated by a significantly lower median ΔPRx during preserved autoregulation periods compared to the control group.
- * The study concludes that while there was no noticeable difference in overall PRx averages, targeting CPPopt appears to enhance cerebrovascular reactivity in TBI patients.
Lower Limit of Reactivity Assessed with PRx in an Experimental Setting.
Acta Neurochir Suppl
June 2021
Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK.
In traumatic brain injury, longer time spent with a cerebral perfusion pressure (CPP) below the pressure reactivity index (PRx)-derived lower limit of reactivity (LLR) has been shown to be statistically associated with higher mortality. We set out to scrutinise the behaviour of LLR and the methods of its estimation in individual cases by performing retrospective analysis of intracranial pressure (ICP), arterial blood pressure (ABP) and laser Doppler flow (LDF) signals recorded in nine piglets undergoing controlled, terminal hypotension. We focused on the sections of the recordings with stable experimental conditions where a clear breakpoint of LDF/CPP characteristic (LLA) could be identified.
View Article and Find Full Text PDFStatistical Signal Properties of the Pressure-Reactivity Index (PRx).
Acta Neurochir Suppl
July 2018
Division of Anaesthesia, University of Cambridge, Cambridge, UK.
Objectives: The pressure-reactivity index (PRx) is defined in terms of the moving correlation coefficient between intracranial pressure (ICP) and mean arterial pressure (MAP) and is a measure of cerebral autoregulation ability. Plots of PRx against cerebral perfusion pressure (CPP) show a U-shaped behaviour: the minimum reflecting optimal cerebral autoregulation (CPPopt). However U-shaped behaviour may also occur by chance.
View Article and Find Full Text PDFOccurrence of CPPopt Values in Uncorrelated ICP and ABP Time Series.
Acta Neurochir Suppl
July 2018
Division of Neurosurgery, Department of Clinical Neurosciences, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK.
Objectives: Optimal cerebral perfusion pressure (CPPopt) is a concept that uses the pressure reactivity (PRx)-CPP relationship over a given period to find a value of CPP at which PRx shows best autoregulation. It has been proposed that this relationship be modelled by a U-shaped curve, where the minimum is interpreted as being the CPP value that corresponds to the strongest autoregulation. Owing to the nature of the calculation and the signals involved in it, the occurrence of CPPopt curves generated by non-physiological variations of intracranial pressure (ICP) and arterial blood pressure (ABP), termed here "false positives", is possible.
View Article and Find Full Text PDFVisualisation of the 'Optimal Cerebral Perfusion' Landscape in Severe Traumatic Brain Injury Patients.
Acta Neurochir Suppl
July 2018
Department of Neurology, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands.
Objective: An 'optimal' cerebral perfusion pressure (CPPopt) can be defined as the point on the CPP scale corresponding to the greatest autoregulatory capacity. This can be established by examining the pressure reactivity index PRx-CPP relationship, which is approximately U-shaped but suffers from noise and missing data. In this paper, we present a method for plotting the whole PRx-CPP relationship curve against time in the form of a colour-coded map depicting the 'landscape' of that relationship extending back for several hours and to display this robustly at the bedside.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!