The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Marek Czosnyka - One of the best experts on this subject based on the ideXlab platform.
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an update on the cogitate phase ii study feasibility and safety of targeting an optimal Cerebral Perfusion Pressure as a patient tailored therapy in severe traumatic brain injury
Acta Neurochirurgica, 2021Co-Authors: Jeanette Tas, Ari Ercole, Marek Czosnyka, Erta Beqiri, Manuel Cabeleira, Bart Depreitere, C R Van Kaam, Gert Bellen, D Bruyninckx, Joseph DonnellyAbstract:Introduction: Monitoring of Cerebral autoregulation (CA) in patients with a traumatic brain injury (TBI) can provide an individual ‘optimal’ Cerebral Perfusion Pressure (CPP) target (CPPopt) at which CA is best preserved. This potentially offers an individualized precision medicine approach. Retrospective data suggest that deviation of CPP from CPPopt is associated with poor outcomes. We are prospectively assessing the feasibility and safety of this approach in the COGiTATE [CPPopt Guided Therapy: Assessment of Target Effectiveness] study. Its primary objective is to demonstrate the feasibility of individualizing CPP at CPPopt in TBI patients. The secondary objectives are to investigate the safety and physiological effects of this strategy.
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transcranial doppler as a non invasive method to estimate Cerebral Perfusion Pressure in children with severe traumatic brain injury
Childs Nervous System, 2020Co-Authors: Francisco Abecasis, Chiara Robba, Danilo Cardim, Marek Czosnyka, Shruti AgrawalAbstract:Introduction Cerebral Perfusion Pressure (CPP) is one of the most important parameters in preventing ischemic brain insults. Guidelines have used CPP values to guide treatment of traumatic brain injury (TBI) for many years. We tested the feasibility of a novel non-invasive method for CPP estimation (nCPP) in children with severe TBI.
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midline shift in patients with closed traumatic brain injury may be driven by Cerebral Perfusion Pressure not intracranial Pressure
Journal of Neurosurgical Sciences, 2019Co-Authors: Danilo Cardim, Peter Smielewski, Chiara Robba, Joseph Donnelly, Bernhard Schmidt, Eric A Schmidt, Michal Bohdanowicz, Marek CzosnykaAbstract:BACKGROUND In traumatic brain injury (TBI), swelling may disturb the potentially uniform Pressure distribution in the brain, producing sustained intercompartmental Pressure gradients which may associate with midline shift. The presence of Pressure gradients is often neglected since bilateral invasive intracranial Pressure (ICP) monitoring is not usually considered because of risks and high costs. We evaluated the presence of interhemispheric Pressure gradients using bilateral transcranial Doppler (TCD) as means for non-invasive ICP (nICP) monitoring in TBI patients presenting midline shift. METHODS From a retrospective cohort of 97 TBI patients with arterial blood Pressure (ABP), ICP and bilateral TCD monitoring, 24 presented unilateral lesion and midline shift confirmed by computer tomography. nICP and non-invasive Cerebral Perfusion Pressure (nCPP) on the left and right brain hemispheres were retrospectively calculated using a mathematical model associating TCD-derived Cerebral blood flow velocity and ABP. RESULTS The nCPP difference was correlated with midline shift (R=-0.34, p<.01) showing a tendency to record higher CPP at the side of expansion. Accordingly, nICP at the side of expansion was significantly lower in comparison to the compressed side (18.86 [±5.71] mmHg (mean ± standard deviation) versus 20.30 [±6.78] mmHg for expansion and compressed sides, respectively). Subsequently, nCPP was greater on the side of brain expansion (79.48±7.84, 78.03±8.93 mmHg [p<.01], for expansion and compressed sides, respectively). CONCLUSIONS TCD-based interhemispheric nCPP difference showed significant correlation with midline shift. Cerebral Perfusion Pressure was greater on the side of brain expansion, acting as the driving force to shift brain structures.
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optimal Cerebral Perfusion Pressure via transcranial doppler in tbi application of robotic technology
Acta Neurochirurgica, 2018Co-Authors: Frederick A Zeiler, Marek Czosnyka, Peter SmielewskiAbstract:Individualized Cerebral Perfusion Pressure (CPP) targets may be derived via assessing the minimum of the parabolic relationship between an index of cerebrovascular reactivity and CPP. This minimum is termed the optimal CPP (CPPopt), and literature suggests that the further away CPP is from CPPopt, the worse is clinical outcome in adult traumatic brain injury (TBI). Typically, CPPopt estimation is based on intracranial Pressure (ICP)-derived cerebrovascular reactivity indices, given ICP is commonly measured and provides continuous long duration data streams. The goal of this study is to describe for the first time the application of robotic transcranial Doppler (TCD) and the feasibility of determining CPPopt based on TCD autoregulation indices.
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optimal Cerebral Perfusion Pressure in centers with different treatment protocols
Critical Care Medicine, 2018Co-Authors: Tim Howells, Per Enblad, Peter J Hutchinson, David K Menon, Peter Smielewski, Marek Czosnyka, Joseph Donnelly, Marcel J H AriesAbstract:The three centers in this study have different policies regarding Cerebral Perfusion Pressure targets and use of vasopressors in traumatic brain injury patients. The aim was to determine if the different policies affected the estimation of Cerebral Perfusion Pressure which optimizes the strength of Cerebral autoregulation, termed "optimal Cerebral Perfusion Pressure."Retrospective analysis of prospectively collected data.Three neurocritical care units at university hospitals in Cambridge, United Kingdom, Groningen, the Netherlands, and Uppsala, Sweden.A total of 104 traumatic brain injury patients were included: 35 each from Cambridge and Groningen, and 34 from Uppsala.None.In Groningen, the Cerebral Perfusion Pressure target was greater than or equal to 50 and less than 70 mm Hg, in Uppsala greater than or equal to 60, and in Cambridge greater than or equal to 60 or preferably greater than or equal to 70. Despite protocol differences, median Cerebral Perfusion Pressure for each center was above 70 mm Hg. Optimal Cerebral Perfusion Pressure was calculated as previously published and implemented in the Intensive Care Monitoring+ software by the Cambridge group, now replicated in the Odin software in Uppsala. Periods with Cerebral Perfusion Pressure above and below optimal Cerebral Perfusion Pressure were analyzed, as were absolute difference between Cerebral Perfusion Pressure and optimal Cerebral Perfusion Pressure and percentage of monitoring time with a valid optimal Cerebral Perfusion Pressure. Uppsala had the highest Cerebral Perfusion Pressure/optimal Cerebral Perfusion Pressure difference. Uppsala patients were older than the other centers, and age is positively correlated with Cerebral Perfusion Pressure/optimal Cerebral Perfusion Pressure difference. Optimal Cerebral Perfusion Pressure was significantly lower in Groningen than in Cambridge. There were no significant differences in percentage of monitoring time with valid optimal Cerebral Perfusion Pressure. Summary optimal Cerebral Perfusion Pressure curves were generated for the combined patient data for each center. These summary curves could be generated for Groningen and Cambridge, but not Uppsala. The older age of the Uppsala patient cohort may explain the absence of a summary curve.Differences in optimal Cerebral Perfusion Pressure calculation were found between centers due to demographics (age) and treatment (Cerebral Perfusion Pressure targets). These factors should be considered in the design of trials to determine the efficacy of autoregulation-guided treatment.
Peter Smielewski - One of the best experts on this subject based on the ideXlab platform.
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midline shift in patients with closed traumatic brain injury may be driven by Cerebral Perfusion Pressure not intracranial Pressure
Journal of Neurosurgical Sciences, 2019Co-Authors: Danilo Cardim, Peter Smielewski, Chiara Robba, Joseph Donnelly, Bernhard Schmidt, Eric A Schmidt, Michal Bohdanowicz, Marek CzosnykaAbstract:BACKGROUND In traumatic brain injury (TBI), swelling may disturb the potentially uniform Pressure distribution in the brain, producing sustained intercompartmental Pressure gradients which may associate with midline shift. The presence of Pressure gradients is often neglected since bilateral invasive intracranial Pressure (ICP) monitoring is not usually considered because of risks and high costs. We evaluated the presence of interhemispheric Pressure gradients using bilateral transcranial Doppler (TCD) as means for non-invasive ICP (nICP) monitoring in TBI patients presenting midline shift. METHODS From a retrospective cohort of 97 TBI patients with arterial blood Pressure (ABP), ICP and bilateral TCD monitoring, 24 presented unilateral lesion and midline shift confirmed by computer tomography. nICP and non-invasive Cerebral Perfusion Pressure (nCPP) on the left and right brain hemispheres were retrospectively calculated using a mathematical model associating TCD-derived Cerebral blood flow velocity and ABP. RESULTS The nCPP difference was correlated with midline shift (R=-0.34, p<.01) showing a tendency to record higher CPP at the side of expansion. Accordingly, nICP at the side of expansion was significantly lower in comparison to the compressed side (18.86 [±5.71] mmHg (mean ± standard deviation) versus 20.30 [±6.78] mmHg for expansion and compressed sides, respectively). Subsequently, nCPP was greater on the side of brain expansion (79.48±7.84, 78.03±8.93 mmHg [p<.01], for expansion and compressed sides, respectively). CONCLUSIONS TCD-based interhemispheric nCPP difference showed significant correlation with midline shift. Cerebral Perfusion Pressure was greater on the side of brain expansion, acting as the driving force to shift brain structures.
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optimal Cerebral Perfusion Pressure via transcranial doppler in tbi application of robotic technology
Acta Neurochirurgica, 2018Co-Authors: Frederick A Zeiler, Marek Czosnyka, Peter SmielewskiAbstract:Individualized Cerebral Perfusion Pressure (CPP) targets may be derived via assessing the minimum of the parabolic relationship between an index of cerebrovascular reactivity and CPP. This minimum is termed the optimal CPP (CPPopt), and literature suggests that the further away CPP is from CPPopt, the worse is clinical outcome in adult traumatic brain injury (TBI). Typically, CPPopt estimation is based on intracranial Pressure (ICP)-derived cerebrovascular reactivity indices, given ICP is commonly measured and provides continuous long duration data streams. The goal of this study is to describe for the first time the application of robotic transcranial Doppler (TCD) and the feasibility of determining CPPopt based on TCD autoregulation indices.
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optimal Cerebral Perfusion Pressure in centers with different treatment protocols
Critical Care Medicine, 2018Co-Authors: Tim Howells, Per Enblad, Peter J Hutchinson, David K Menon, Peter Smielewski, Marek Czosnyka, Joseph Donnelly, Marcel J H AriesAbstract:The three centers in this study have different policies regarding Cerebral Perfusion Pressure targets and use of vasopressors in traumatic brain injury patients. The aim was to determine if the different policies affected the estimation of Cerebral Perfusion Pressure which optimizes the strength of Cerebral autoregulation, termed "optimal Cerebral Perfusion Pressure."Retrospective analysis of prospectively collected data.Three neurocritical care units at university hospitals in Cambridge, United Kingdom, Groningen, the Netherlands, and Uppsala, Sweden.A total of 104 traumatic brain injury patients were included: 35 each from Cambridge and Groningen, and 34 from Uppsala.None.In Groningen, the Cerebral Perfusion Pressure target was greater than or equal to 50 and less than 70 mm Hg, in Uppsala greater than or equal to 60, and in Cambridge greater than or equal to 60 or preferably greater than or equal to 70. Despite protocol differences, median Cerebral Perfusion Pressure for each center was above 70 mm Hg. Optimal Cerebral Perfusion Pressure was calculated as previously published and implemented in the Intensive Care Monitoring+ software by the Cambridge group, now replicated in the Odin software in Uppsala. Periods with Cerebral Perfusion Pressure above and below optimal Cerebral Perfusion Pressure were analyzed, as were absolute difference between Cerebral Perfusion Pressure and optimal Cerebral Perfusion Pressure and percentage of monitoring time with a valid optimal Cerebral Perfusion Pressure. Uppsala had the highest Cerebral Perfusion Pressure/optimal Cerebral Perfusion Pressure difference. Uppsala patients were older than the other centers, and age is positively correlated with Cerebral Perfusion Pressure/optimal Cerebral Perfusion Pressure difference. Optimal Cerebral Perfusion Pressure was significantly lower in Groningen than in Cambridge. There were no significant differences in percentage of monitoring time with valid optimal Cerebral Perfusion Pressure. Summary optimal Cerebral Perfusion Pressure curves were generated for the combined patient data for each center. These summary curves could be generated for Groningen and Cambridge, but not Uppsala. The older age of the Uppsala patient cohort may explain the absence of a summary curve.Differences in optimal Cerebral Perfusion Pressure calculation were found between centers due to demographics (age) and treatment (Cerebral Perfusion Pressure targets). These factors should be considered in the design of trials to determine the efficacy of autoregulation-guided treatment.
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Optimal Cerebral Perfusion Pressure in Centers With Different Treatment Protocols.
Critical care medicine, 2018Co-Authors: Tim Howells, Per Enblad, Peter J Hutchinson, David K Menon, Peter Smielewski, Marek Czosnyka, Joseph Donnelly, Marcel J H AriesAbstract:Objectives The three centers in this study have different policies regarding Cerebral Perfusion Pressure targets and use of vasopressors in traumatic brain injury patients. The aim was to determine if the different policies affected the estimation of Cerebral Perfusion Pressure which optimizes the strength of Cerebral autoregulation, termed "optimal Cerebral Perfusion Pressure." Design Retrospective analysis of prospectively collected data. Setting Three neurocritical care units at university hospitals in Cambridge, United Kingdom, Groningen, the Netherlands, and Uppsala, Sweden. Patients A total of 104 traumatic brain injury patients were included: 35 each from Cambridge and Groningen, and 34 from Uppsala. Interventions None. Measurements and main results In Groningen, the Cerebral Perfusion Pressure target was greater than or equal to 50 and less than 70 mm Hg, in Uppsala greater than or equal to 60, and in Cambridge greater than or equal to 60 or preferably greater than or equal to 70. Despite protocol differences, median Cerebral Perfusion Pressure for each center was above 70 mm Hg. Optimal Cerebral Perfusion Pressure was calculated as previously published and implemented in the Intensive Care Monitoring+ software by the Cambridge group, now replicated in the Odin software in Uppsala. Periods with Cerebral Perfusion Pressure above and below optimal Cerebral Perfusion Pressure were analyzed, as were absolute difference between Cerebral Perfusion Pressure and optimal Cerebral Perfusion Pressure and percentage of monitoring time with a valid optimal Cerebral Perfusion Pressure. Uppsala had the highest Cerebral Perfusion Pressure/optimal Cerebral Perfusion Pressure difference. Uppsala patients were older than the other centers, and age is positively correlated with Cerebral Perfusion Pressure/optimal Cerebral Perfusion Pressure difference. Optimal Cerebral Perfusion Pressure was significantly lower in Groningen than in Cambridge. There were no significant differences in percentage of monitoring time with valid optimal Cerebral Perfusion Pressure. Summary optimal Cerebral Perfusion Pressure curves were generated for the combined patient data for each center. These summary curves could be generated for Groningen and Cambridge, but not Uppsala. The older age of the Uppsala patient cohort may explain the absence of a summary curve. Conclusions Differences in optimal Cerebral Perfusion Pressure calculation were found between centers due to demographics (age) and treatment (Cerebral Perfusion Pressure targets). These factors should be considered in the design of trials to determine the efficacy of autoregulation-guided treatment.
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survey in expert clinicians on the validity of automated calculation of optimal Cerebral Perfusion Pressure
Minerva Anestesiologica, 2018Co-Authors: Romy Steij, Ari Ercole, Peter Smielewski, Marek Czosnyka, Joseph Donnelly, Jan Willem J Elting, Roy E Stewa, Antony Absalom, Christina Haubrich, Marcel J H AriesAbstract:BACKGROUND: Optimal Cerebral Perfusion Pressure (CPPopt) targeting in traumatic brain injury (TBI) patients constitutes an active and controversial area of research. It has been suggested that an autoregulation guided CPP therapy may improve TBI outcome. Prerequisites of a CPPopt intervention study would be objective criteria for the CPPopt detection. This study compared the agreement between automated and visual CPPopt detection. METHODS: Twenty-five clinicians from 18 centers worldwide, familiar with brain monitoring and using dedicated software, reviewed ten 4-hour CPPopt screenshots at 48 hours after ictus in selected TBI patients. Each screenshot displayed the trends of Cerebral Perfusion Pressure (CPP), intracranial Pressure (ICP), cerebrovascular Pressure reactivity (PRx) as well as the "CPP-optimal" curve and its associated value (automated CPPopt). The main objective was to evaluate the agreement between expert clinicians as well as the agreement between the clinicians and automated CPPopt. RESULTS : Twenty-two clinicians responded to our call (88%). Three screenshots were judged as "CPPopt not determinable" by > 45% of the clinicians. For the whole group, the consensus between automated CPPopt and clinicians' visual CPPopt was high. Three clinicians were identified as outliers. All clinicians recommended to modify CPP when patients differed >+/- 5 mmHg from their CPPopt. The inter-observer consensus was highest in cases with current CPP below the optimal value. CONCLUSIONS: The overall agreement between automated CPPopt and visual CPPopt identified by autoregulation experts was high, except for those cases when the curve was deemed by the clinicians not reliable enough to yield a trustworthy CPPopt.
Marcel J H Aries - One of the best experts on this subject based on the ideXlab platform.
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optimal Cerebral Perfusion Pressure assessed with a multi window weighted approach adapted for prospective use a validation study
Acta Neurochirurgica, 2021Co-Authors: Erta Beqiri, Ari Ercole, Marcel J H Aries, Joseph Donnelly, Manuel Cabeleira, Andras Czigler, Annalisa Liberti, Jeanette Tas, Xiuyun LiuAbstract:BACKGROUND Pressure reactivity index (PRx)-Cerebral Perfusion Pressure (CPP) relationships over a given time period can be used to detect a value of CPP at which PRx shows the best autoregulation (optimal CPP, or CPPopt). Algorithms for continuous assessment of CPPopt in traumatic brain injury (TBI) patients reached the desired high yield with a multi-window approach (CPPopt_MA). However, the calculations were tested on retrospective manually cleaned datasets. Moreover, CPPopt false-positive values can be generated from non-physiological variations of intracranial Pressure (ICP) and arterial blood Pressure (ABP). Therefore, the algorithm robustness was improved, making it suitable for prospective bedside application (COGiTATE trial). OBJECTIVE To validate the CPPopt revised algorithm in a large single-centre retrospective cohort of TBI patients. METHODS 840 TBI patients were included. CPPopt yield, stability and ability to discriminate outcome groups were compared to CPPopt_MA and the Brain Trauma Foundation (BTF) guideline reference. RESULTS CPPopt yield was lower than CPPopt_MA yield (85% and 90%, p < 0.001), but, importantly, with increased stability (p < 0.0001). The ∆(CPP-CPPopt) could distinguish the mortality and survival outcome (t = -6.7, p < 0.0001) with a statistical significance higher than the ∆CPP calculated with the guideline reference (CPP-60) (t = -4.5, p < 0.0001). CONCLUSION This study validates, on a large cohort of patients, the new algorithm proposed for prospective use of CPPopt as a CPP target at bedside.
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optimal Cerebral Perfusion Pressure in centers with different treatment protocols
Critical Care Medicine, 2018Co-Authors: Tim Howells, Per Enblad, Peter J Hutchinson, David K Menon, Peter Smielewski, Marek Czosnyka, Joseph Donnelly, Marcel J H AriesAbstract:The three centers in this study have different policies regarding Cerebral Perfusion Pressure targets and use of vasopressors in traumatic brain injury patients. The aim was to determine if the different policies affected the estimation of Cerebral Perfusion Pressure which optimizes the strength of Cerebral autoregulation, termed "optimal Cerebral Perfusion Pressure."Retrospective analysis of prospectively collected data.Three neurocritical care units at university hospitals in Cambridge, United Kingdom, Groningen, the Netherlands, and Uppsala, Sweden.A total of 104 traumatic brain injury patients were included: 35 each from Cambridge and Groningen, and 34 from Uppsala.None.In Groningen, the Cerebral Perfusion Pressure target was greater than or equal to 50 and less than 70 mm Hg, in Uppsala greater than or equal to 60, and in Cambridge greater than or equal to 60 or preferably greater than or equal to 70. Despite protocol differences, median Cerebral Perfusion Pressure for each center was above 70 mm Hg. Optimal Cerebral Perfusion Pressure was calculated as previously published and implemented in the Intensive Care Monitoring+ software by the Cambridge group, now replicated in the Odin software in Uppsala. Periods with Cerebral Perfusion Pressure above and below optimal Cerebral Perfusion Pressure were analyzed, as were absolute difference between Cerebral Perfusion Pressure and optimal Cerebral Perfusion Pressure and percentage of monitoring time with a valid optimal Cerebral Perfusion Pressure. Uppsala had the highest Cerebral Perfusion Pressure/optimal Cerebral Perfusion Pressure difference. Uppsala patients were older than the other centers, and age is positively correlated with Cerebral Perfusion Pressure/optimal Cerebral Perfusion Pressure difference. Optimal Cerebral Perfusion Pressure was significantly lower in Groningen than in Cambridge. There were no significant differences in percentage of monitoring time with valid optimal Cerebral Perfusion Pressure. Summary optimal Cerebral Perfusion Pressure curves were generated for the combined patient data for each center. These summary curves could be generated for Groningen and Cambridge, but not Uppsala. The older age of the Uppsala patient cohort may explain the absence of a summary curve.Differences in optimal Cerebral Perfusion Pressure calculation were found between centers due to demographics (age) and treatment (Cerebral Perfusion Pressure targets). These factors should be considered in the design of trials to determine the efficacy of autoregulation-guided treatment.
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Optimal Cerebral Perfusion Pressure in Centers With Different Treatment Protocols.
Critical care medicine, 2018Co-Authors: Tim Howells, Per Enblad, Peter J Hutchinson, David K Menon, Peter Smielewski, Marek Czosnyka, Joseph Donnelly, Marcel J H AriesAbstract:Objectives The three centers in this study have different policies regarding Cerebral Perfusion Pressure targets and use of vasopressors in traumatic brain injury patients. The aim was to determine if the different policies affected the estimation of Cerebral Perfusion Pressure which optimizes the strength of Cerebral autoregulation, termed "optimal Cerebral Perfusion Pressure." Design Retrospective analysis of prospectively collected data. Setting Three neurocritical care units at university hospitals in Cambridge, United Kingdom, Groningen, the Netherlands, and Uppsala, Sweden. Patients A total of 104 traumatic brain injury patients were included: 35 each from Cambridge and Groningen, and 34 from Uppsala. Interventions None. Measurements and main results In Groningen, the Cerebral Perfusion Pressure target was greater than or equal to 50 and less than 70 mm Hg, in Uppsala greater than or equal to 60, and in Cambridge greater than or equal to 60 or preferably greater than or equal to 70. Despite protocol differences, median Cerebral Perfusion Pressure for each center was above 70 mm Hg. Optimal Cerebral Perfusion Pressure was calculated as previously published and implemented in the Intensive Care Monitoring+ software by the Cambridge group, now replicated in the Odin software in Uppsala. Periods with Cerebral Perfusion Pressure above and below optimal Cerebral Perfusion Pressure were analyzed, as were absolute difference between Cerebral Perfusion Pressure and optimal Cerebral Perfusion Pressure and percentage of monitoring time with a valid optimal Cerebral Perfusion Pressure. Uppsala had the highest Cerebral Perfusion Pressure/optimal Cerebral Perfusion Pressure difference. Uppsala patients were older than the other centers, and age is positively correlated with Cerebral Perfusion Pressure/optimal Cerebral Perfusion Pressure difference. Optimal Cerebral Perfusion Pressure was significantly lower in Groningen than in Cambridge. There were no significant differences in percentage of monitoring time with valid optimal Cerebral Perfusion Pressure. Summary optimal Cerebral Perfusion Pressure curves were generated for the combined patient data for each center. These summary curves could be generated for Groningen and Cambridge, but not Uppsala. The older age of the Uppsala patient cohort may explain the absence of a summary curve. Conclusions Differences in optimal Cerebral Perfusion Pressure calculation were found between centers due to demographics (age) and treatment (Cerebral Perfusion Pressure targets). These factors should be considered in the design of trials to determine the efficacy of autoregulation-guided treatment.
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survey in expert clinicians on the validity of automated calculation of optimal Cerebral Perfusion Pressure
Minerva Anestesiologica, 2018Co-Authors: Romy Steij, Ari Ercole, Peter Smielewski, Marek Czosnyka, Joseph Donnelly, Jan Willem J Elting, Roy E Stewa, Antony Absalom, Christina Haubrich, Marcel J H AriesAbstract:BACKGROUND: Optimal Cerebral Perfusion Pressure (CPPopt) targeting in traumatic brain injury (TBI) patients constitutes an active and controversial area of research. It has been suggested that an autoregulation guided CPP therapy may improve TBI outcome. Prerequisites of a CPPopt intervention study would be objective criteria for the CPPopt detection. This study compared the agreement between automated and visual CPPopt detection. METHODS: Twenty-five clinicians from 18 centers worldwide, familiar with brain monitoring and using dedicated software, reviewed ten 4-hour CPPopt screenshots at 48 hours after ictus in selected TBI patients. Each screenshot displayed the trends of Cerebral Perfusion Pressure (CPP), intracranial Pressure (ICP), cerebrovascular Pressure reactivity (PRx) as well as the "CPP-optimal" curve and its associated value (automated CPPopt). The main objective was to evaluate the agreement between expert clinicians as well as the agreement between the clinicians and automated CPPopt. RESULTS : Twenty-two clinicians responded to our call (88%). Three screenshots were judged as "CPPopt not determinable" by > 45% of the clinicians. For the whole group, the consensus between automated CPPopt and clinicians' visual CPPopt was high. Three clinicians were identified as outliers. All clinicians recommended to modify CPP when patients differed >+/- 5 mmHg from their CPPopt. The inter-observer consensus was highest in cases with current CPP below the optimal value. CONCLUSIONS: The overall agreement between automated CPPopt and visual CPPopt identified by autoregulation experts was high, except for those cases when the curve was deemed by the clinicians not reliable enough to yield a trustworthy CPPopt.
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monitoring of optimal Cerebral Perfusion Pressure in traumatic brain injured patients using a multi window weighting algorithm
Journal of Neurotrauma, 2017Co-Authors: Xiuyun Liu, Ari Ercole, Danilo Cardim, Marek Czosnyka, Marcel J H Aries, Joseph Donnelly, Natasha M Maurits, Dongjoo Kim, Celeste DiasAbstract:Abstract Methods to identify an autoregulation guided “optimal” Cerebral Perfusion Pressure (CPPopt) for traumatic brain injury patients (TBI) have been reported through several studies. An important drawback of existing methodology is that CPPopt can be calculated only in ∼50–60% of the monitoring time. In this study, we hypothesized that the CPPopt yield and the continuity can be improved significantly through application of a multi-window and weighting calculation algorithm, without adversely affecting preservation of its prognostic value. Data of 526 severe TBI patients admitted between 2003 and 2015 were studied. The multi-window CPPopt calculation was based on automated curve fitting in Pressure reactivity index (PRx)-CPP plots using data from 36 increasing length time windows (2–8 h). The resulting matrix of CPPopts was then averaged in a weighted manner. The yield, continuity, and stability of CPPopt were studied. The difference between patients' actual CPP and CPPopt (ΔCPP) was calculated and the...
Peter J Hutchinson - One of the best experts on this subject based on the ideXlab platform.
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optimal Cerebral Perfusion Pressure in centers with different treatment protocols
Critical Care Medicine, 2018Co-Authors: Tim Howells, Per Enblad, Peter J Hutchinson, David K Menon, Peter Smielewski, Marek Czosnyka, Joseph Donnelly, Marcel J H AriesAbstract:The three centers in this study have different policies regarding Cerebral Perfusion Pressure targets and use of vasopressors in traumatic brain injury patients. The aim was to determine if the different policies affected the estimation of Cerebral Perfusion Pressure which optimizes the strength of Cerebral autoregulation, termed "optimal Cerebral Perfusion Pressure."Retrospective analysis of prospectively collected data.Three neurocritical care units at university hospitals in Cambridge, United Kingdom, Groningen, the Netherlands, and Uppsala, Sweden.A total of 104 traumatic brain injury patients were included: 35 each from Cambridge and Groningen, and 34 from Uppsala.None.In Groningen, the Cerebral Perfusion Pressure target was greater than or equal to 50 and less than 70 mm Hg, in Uppsala greater than or equal to 60, and in Cambridge greater than or equal to 60 or preferably greater than or equal to 70. Despite protocol differences, median Cerebral Perfusion Pressure for each center was above 70 mm Hg. Optimal Cerebral Perfusion Pressure was calculated as previously published and implemented in the Intensive Care Monitoring+ software by the Cambridge group, now replicated in the Odin software in Uppsala. Periods with Cerebral Perfusion Pressure above and below optimal Cerebral Perfusion Pressure were analyzed, as were absolute difference between Cerebral Perfusion Pressure and optimal Cerebral Perfusion Pressure and percentage of monitoring time with a valid optimal Cerebral Perfusion Pressure. Uppsala had the highest Cerebral Perfusion Pressure/optimal Cerebral Perfusion Pressure difference. Uppsala patients were older than the other centers, and age is positively correlated with Cerebral Perfusion Pressure/optimal Cerebral Perfusion Pressure difference. Optimal Cerebral Perfusion Pressure was significantly lower in Groningen than in Cambridge. There were no significant differences in percentage of monitoring time with valid optimal Cerebral Perfusion Pressure. Summary optimal Cerebral Perfusion Pressure curves were generated for the combined patient data for each center. These summary curves could be generated for Groningen and Cambridge, but not Uppsala. The older age of the Uppsala patient cohort may explain the absence of a summary curve.Differences in optimal Cerebral Perfusion Pressure calculation were found between centers due to demographics (age) and treatment (Cerebral Perfusion Pressure targets). These factors should be considered in the design of trials to determine the efficacy of autoregulation-guided treatment.
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Optimal Cerebral Perfusion Pressure in Centers With Different Treatment Protocols.
Critical care medicine, 2018Co-Authors: Tim Howells, Per Enblad, Peter J Hutchinson, David K Menon, Peter Smielewski, Marek Czosnyka, Joseph Donnelly, Marcel J H AriesAbstract:Objectives The three centers in this study have different policies regarding Cerebral Perfusion Pressure targets and use of vasopressors in traumatic brain injury patients. The aim was to determine if the different policies affected the estimation of Cerebral Perfusion Pressure which optimizes the strength of Cerebral autoregulation, termed "optimal Cerebral Perfusion Pressure." Design Retrospective analysis of prospectively collected data. Setting Three neurocritical care units at university hospitals in Cambridge, United Kingdom, Groningen, the Netherlands, and Uppsala, Sweden. Patients A total of 104 traumatic brain injury patients were included: 35 each from Cambridge and Groningen, and 34 from Uppsala. Interventions None. Measurements and main results In Groningen, the Cerebral Perfusion Pressure target was greater than or equal to 50 and less than 70 mm Hg, in Uppsala greater than or equal to 60, and in Cambridge greater than or equal to 60 or preferably greater than or equal to 70. Despite protocol differences, median Cerebral Perfusion Pressure for each center was above 70 mm Hg. Optimal Cerebral Perfusion Pressure was calculated as previously published and implemented in the Intensive Care Monitoring+ software by the Cambridge group, now replicated in the Odin software in Uppsala. Periods with Cerebral Perfusion Pressure above and below optimal Cerebral Perfusion Pressure were analyzed, as were absolute difference between Cerebral Perfusion Pressure and optimal Cerebral Perfusion Pressure and percentage of monitoring time with a valid optimal Cerebral Perfusion Pressure. Uppsala had the highest Cerebral Perfusion Pressure/optimal Cerebral Perfusion Pressure difference. Uppsala patients were older than the other centers, and age is positively correlated with Cerebral Perfusion Pressure/optimal Cerebral Perfusion Pressure difference. Optimal Cerebral Perfusion Pressure was significantly lower in Groningen than in Cambridge. There were no significant differences in percentage of monitoring time with valid optimal Cerebral Perfusion Pressure. Summary optimal Cerebral Perfusion Pressure curves were generated for the combined patient data for each center. These summary curves could be generated for Groningen and Cambridge, but not Uppsala. The older age of the Uppsala patient cohort may explain the absence of a summary curve. Conclusions Differences in optimal Cerebral Perfusion Pressure calculation were found between centers due to demographics (age) and treatment (Cerebral Perfusion Pressure targets). These factors should be considered in the design of trials to determine the efficacy of autoregulation-guided treatment.
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Pressure reactivity based optimal Cerebral Perfusion Pressure in a traumatic brain injury cohort
Acta Neurochirurgica, 2018Co-Authors: Joseph Donnelly, Luzius A Steiner, Ari Ercole, Hadie Adams, Chiara Robba, Danilo Cardim, Brenno Caetano Troca Cabella, Marek Czosnyka, Peter J HutchinsonAbstract:Objectives: Retrospective data from patients with severe traumatic brain injury (TBI) indicate that deviation from the continuously calculated Pressure reactivity-based “optimal” Cerebral Perfusion Pressure (CPPopt) is associated with worse patient outcome. The objective of this study was to assess the relationship between prospectively collected CPPopt data and patient outcome after TBI.
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individualizing thresholds of Cerebral Perfusion Pressure using estimated limits of autoregulation
Critical Care Medicine, 2017Co-Authors: Joseph Donnelly, Luzius A Steiner, Ari Ercole, Peter J Hutchinson, Hadie Adams, Chiara Robba, Danilo Cardim, Brenno Caetano Troca Cabella, Marek Czosnyka, David K MenonAbstract:Objectives:In severe traumatic brain injury, Cerebral Perfusion Pressure management based on cerebrovascular Pressure reactivity index has the potential to provide a personalized treatment target to improve patient outcomes. So far, the methods have focused on identifying “one” autoregulation-guided
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a noninvasive estimation of Cerebral Perfusion Pressure using critical closing Pressure
Journal of Neurosurgery, 2015Co-Authors: Georgios V Varsos, Peter J Hutchinson, Peter Smielewski, John D. Pickard, Marek Czosnyka, Angelos G Kolias, Ken M Brady, Vassilis G VarsosAbstract:OBJECT Cerebral blood flow is associated with Cerebral Perfusion Pressure (CPP), which is clinically monitored through arterial blood Pressure (ABP) and invasive measurements of intracranial Pressure (ICP). Based on critical closing Pressure (CrCP), the authors introduce a novel method for a noninvasive estimator of CPP (eCPP). METHODS Data from 280 head-injured patients with ABP, ICP, and transcranial Doppler ultrasonography measurements were retrospectively examined. CrCP was calculated with a noninvasive version of the cerebrovascular impedance method. The eCPP was refined with a predictive regression model of CrCP-based estimation of ICP from known ICP using data from 232 patients, and validated with data from the remaining 48 patients. RESULTS Cohort analysis showed eCPP to be correlated with measured CPP (R = 0.851, p < 0.001), with a mean ± SD difference of 4.02 ± 6.01 mm Hg, and 83.3% of the cases with an estimation error below 10 mm Hg. eCPP accurately predicted low CPP (< 70 mm Hg) with an area ...
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outcome Pressure reactivity and optimal Cerebral Perfusion Pressure calculation in traumatic brain injury a comparison of two variants
Acta Neurochirurgica, 2016Co-Authors: Erhard W Lang, Peter Smielewski, John D. Pickard, Magdalena Kasprowicz, Edgar Santos, Marek CzosnykaAbstract:This study investigates the outcome prediction and calculation of optimal Cerebral Perfusion Pressure (CPPopt) in 307 patients after severe traumatic brain injury (TBI) based on cerebrovascular reactivity calculation of a moving correlation correlation coefficient, named PRx, between mean arterial Pressure (ABP) and intracranial Pressure (ICP). The correlation coefficient was calculated from simultaneously recorded data using different frequencies. PRx was calculated from oscillations between 0.008 and 0.05Hz and the longPRx (L-PRx) was calculated from oscillations between 0.0008 and 0.016 Hz. PRx was a significant mortality predictor, whereas L-PRx was not. CPPopt for pooled data was higher for L-PRx than for PRx, with no statistical difference. Mortality was associated with mean CPP below CPPopt. Severe disability was associated with CPP above CPPopt (PRx). These relationships were not statistically significant for CPPopt (L-PRx). We conclude that PRx and L-PRx cannot be used interchangeably.
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a noninvasive estimation of Cerebral Perfusion Pressure using critical closing Pressure
Journal of Neurosurgery, 2015Co-Authors: Georgios V Varsos, Peter J Hutchinson, Peter Smielewski, John D. Pickard, Marek Czosnyka, Angelos G Kolias, Ken M Brady, Vassilis G VarsosAbstract:OBJECT Cerebral blood flow is associated with Cerebral Perfusion Pressure (CPP), which is clinically monitored through arterial blood Pressure (ABP) and invasive measurements of intracranial Pressure (ICP). Based on critical closing Pressure (CrCP), the authors introduce a novel method for a noninvasive estimator of CPP (eCPP). METHODS Data from 280 head-injured patients with ABP, ICP, and transcranial Doppler ultrasonography measurements were retrospectively examined. CrCP was calculated with a noninvasive version of the cerebrovascular impedance method. The eCPP was refined with a predictive regression model of CrCP-based estimation of ICP from known ICP using data from 232 patients, and validated with data from the remaining 48 patients. RESULTS Cohort analysis showed eCPP to be correlated with measured CPP (R = 0.851, p < 0.001), with a mean ± SD difference of 4.02 ± 6.01 mm Hg, and 83.3% of the cases with an estimation error below 10 mm Hg. eCPP accurately predicted low CPP (< 70 mm Hg) with an area ...
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optimal Cerebral Perfusion Pressure are we ready for it
Neurological Research, 2013Co-Authors: Christos Lazaridis, Luzius A Steiner, Peter J Hutchinson, Peter Smielewski, John D. Pickard, Kenneth Martin Brady, Marek CzosnykaAbstract:AbstractObjectives: Cerebral Perfusion Pressure (CPP)-oriented therapy and the Lund concept lie on opposite ends of the CPP scale, in the management of head injury. Optimization of CPP by monitoring Cerebral vascular Pressure reactivity is an alternative approach that may reconcile these two divergent approaches, preventing both injurious hypotension and hypertension with an individualized CPP target.Methods: Indices describing Cerebral vascular reactivity or Cerebral blood flow autoregulation, derived from intracranial Pressure, near-infrared spectroscopy, or transcranial Doppler are reviewed in this manuscript.Results: Indices of cerebrovascular reactivity and autoregulation typically converge to a U-shape curve when viewed as a function of CPP, with the best reactivity metrics indicating optimal CPP. In a retrospective study of prospectively collected data from head-injured patients, Steiner et al. demonstrated that a greater distance between averaged over total monitoring time-CPP and optimal CPP, cor...
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continuous determination of optimal Cerebral Perfusion Pressure in traumatic brain injury
Critical Care Medicine, 2012Co-Authors: Marcel J H Aries, Luzius A Steiner, Peter J Hutchinson, David K Menon, Karol P Budohoski, Marek Czosnyka, Angelos G Kolias, Andrea Lavinio, Kenneth Martin Brady, John D. PickardAbstract:Objectives: We have sought to develop an automated methodology for the continuous updating of optimal Cerebral Perfusion Pressure (CPPopt) for patients after severe traumatic head injury, using continuous monitoring of cerebrovascular Pressure reactivity. We then validated the CPPopt algorithm by determining the association between outcome and the deviation of actual CPP from CPPopt. Design: Retrospective analysis of prospectively collected data. Setting: Neurosciences critical care unit of a university hospital. Patients: A total of 327 traumatic head-injury patients admitted between 2003 and 2009 with continuous monitoring of arterial blood Pressure and intracranial Pressure. Measurements and Main Results: Arterial blood Pressure, intracranial Pressure, and CPP were continuously recorded, and Pressure reactivity index was calculated online. Outcome was assessed at 6 months. An automated curve fitting method was applied to determine CPP at the minimum value for Pressure reactivity index (CPPopt). A time trend of CPPopt was created using a moving 4-hr window, updated every minute. Identification of CPPopt was, on average, feasible during 55% of the whole recording period. Patient outcome correlated with the continuously updated difference between median CPP and CPPopt (chi-square = 45, p CPPopt), and favorable outcome was associated with smaller deviations of CPP from the individualized CPPopt. While deviations from global target CPP values of 60 mm Hg and 70 mm Hg were also related to outcome, these relationships were less robust. Conclusions: Real-time CPPopt could be identified during the recording time of majority of the patients. Patients with a median CPP close to CPPopt were more likely to have a favorable outcome than those in whom median CPP was widely different from CPPopt. Deviations from individualized CPPopt were more predictive of outcome than deviations from a common target CPP. CPP management to optimize cerebrovascular Pressure reactivity should be the subject of future clinical trial in severe traumatic head-injury patients. (Crit Care Med 2012; 40:2456-2463)
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optimal Cerebral Perfusion Pressure in poor grade patients after subarachnoid hemorrhage
Neurocritical Care, 2010Co-Authors: Philippe Bijlenga, Martin Soehle, Karol P Budohoski, Peter J Kirkpatrick, John D. Pickard, Marek Czosnyka, Peter SmielewskiAbstract:Background Cerebrovascular Pressure reactivity depends on Cerebral Perfusion Pressure (CPP), with the optimal CPP (CPPopt) defined as Pressure at which cerebrovascular reactivity is functioning optimally, reaching minimal value of Pressure reactivity index (PRx). The study investigates the association between vasospasm, PRx, and CPPopt in poor grade patients (WFNS 4&5) after subarachnoid hemorrhage (SAH).