‘Long’ pressure reactivity index (L-PRx) as a measure of autoregulation correlates with outcome in traumatic brain injury patients

Sánchez-Porras, Renán; Santos, Edgar; Czosnyka, Marek; Zheng, Zijie; Unterberg, Andreas; Sakowitz, Oliver W.

doi:10.1007/s00701-012-1423-0

Cited by 52 publications

(43 citation statements)

References 21 publications

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“…27 Our large TBI series shows that the PRx is significantly higher in patients with fatal outcome (PVS and death) than in patients with nonfatal outcome (good, moderate, severe disability), which we cannot confirm for the L-PRx. This finding brings us to a previously raised issue.…”

Section: Discussionmentioning

confidence: 63%

“…Recently a new PRx, called long (L)-PRx, that considers slower changes in ABP and ICP (within a frequency range of 0.0008-0.008 Hz) has been introduced. 27,28 Its utility and prognostic relevance have been confirmed in a small series of 18 patients with spontaneous intracranial hemorrhage, 28 and in a second series of 29 patients with TBI. 27 The aim of our study was to investigate, by reference to PRx performance, the utility and performance of the L-PRx for long-term outcome assessment and CPPopt calculation in a large TBI series.…”

Section: 29mentioning

confidence: 90%

“…2, 3,14,17,[27][28][29] It is clinically most attractive because it does not require an external stimulus or patient manipulation, and routinely monitored data can be used for clinical research. The PRx has been reported to correlate with outcome after traumatic brain injury (TBI), 14,17 and it is used for online calculation of the optimal cerebral perfusion pressure (CPPopt).…”

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confidence: 99%

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Short pressure reactivity index versus long pressure reactivity index in the management of traumatic brain injury

Lang

Kasprowicz

Smielewski

et al. 2015

JNS

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A rteriAl blood pressure (ABP), intracranial pressure (ICP), cerebral blood flow velocity measured with transcranial Doppler ultrasonography, and cerebral microcirculation assessed by laser Doppler flow are periodical biological signals that can be continuously monitored and recorded in both routine and ICU settings by using invasive and noninvasive techniques and devices. 5,12,16,30,32 These biological signals will show frequency peaks within certain frequency bands.6,11 They can be categorized into two groups: 1) the B waves that occur at approximately 0.5-3 cycles per minute, which corresponds to a frequency of 0.008-0.05 Hz;5,16,23 and 2) M waves, which occur at approximately 4-9 cycles per minute, which corresponds to a frequency of 0.07-0.15 Hz. 7,12,22 The 6 ventiabbreviatioNs ABP = arterial blood pressure; CPPopt = optimal cerebral perfusion pressure; GCS = Glasgow Coma Scale; GOS = Glasgow Outcome Scale; ICP = intracranial pressure; IQR = interquartile range; L-PRx = long pressure reactivity index; PVS = persistent vegetative state; TBI = traumatic brain injury. obJect The pressure reactivity index (PRx) correlates with outcome after traumatic brain injury (TBI) and is used to calculate optimal cerebral perfusion pressure (CPPopt). The PRx is a correlation coefficient between slow, spontaneous changes (0.003-0.05 Hz) in intracranial pressure (ICP) and arterial blood pressure (ABP). A novel index-the so-called long PRx (L-PRx)-that considers ABP and ICP changes (0.0008-0.008 Hz) was proposed. methods The authors compared PRx and L-PRx for 6-month outcome prediction and CPPopt calculation in 307 patients with TBI. The PRx- and L-PRx-based CPPopt were determined and the predictive power and discriminant abilities were compared. results The PRx and L-PRx correlation was good (R = 0.7, p < 0.00001; Spearman test). The PRx, age, CPP, and Glasgow Coma Scale score but not L-PRx were significant fatal outcome predictors (death and persistent vegetative state). There was a significant difference between the areas under the receiver operating characteristic curves calculated for PRx and L-PRx (0.61 ± 0.04 vs 0.51 ± 0.04; z-statistic = -3.26, p = 0.011), which indicates a better ability by PRx than L-PRx to predict fatal outcome. The CPPopt was higher for L-PRx than for PRx, without a statistical difference (median CPPopt for L-PRx: 76.9 mm Hg, interquartile range [IQR] ± 10.1 mm Hg; median CPPopt for PRx: 74.7 mm Hg, IQR ± 8.2 mm Hg). Death was associated with CPP below CPPopt for PRx (c 2 = 30.6, p < 0.00001), and severe disability was associated with CPP above CPPopt for PRx (c 2 = 7.8, p = 0.005). These relationships were not statistically significant for CPPopt for L-PRx. coNclusioNs The PRx is superior to the L-PRx for TBI outcome prediction. Individual CPPopt for L-PRx and PRx are not statistically different. Deviations between CPP and CPPopt for PRx are relevant for outcome prediction; those between CPP and CPPopt for L-PRx are not. The PRx uses the entire B-wave spectrum for index calculation, whereas the ...

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Section: Discussionmentioning

confidence: 63%

Section: 29mentioning

confidence: 90%

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confidence: 99%

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Short pressure reactivity index versus long pressure reactivity index in the management of traumatic brain injury

Lang

Kasprowicz

Smielewski

et al. 2015

JNS

Self Cite

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“…Therefore, the dynamics of rCBF may not correctly reflect the impaired cerebral autoregulation mechanisms. For future studies, it is advisable to measure cranial pressure in order to provide a pressure reactivity index [65,66]. This can be done by using transcranial Doppler ultrasonography [67,68].…”

Section: Discussionmentioning

confidence: 99%

Transhemispheric Diaschisis after Unilateral Focal Cerebral Ischemia Reperfusion: A Longitudinal Voxel-Based Study by MRI

Taheri¹,

Yu²,

Zhu³

et al. 2019

Transl Neurosci Res Rev

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“…This highlights the potential role of microdialysis as an early warning mechanism to perhaps guide earlier therapeutic intervention. Several other studies show that decreases in perfusion and oxygenation in TBI patients are associated with deteriorating cerebral chemistry, and that these effects are more pronounced in perilesional tissue, when cerebrovascular reactivity is impaired (Timofeev et al [10]) and in those patients who die [42].…”

Section: Intracranial Hypertensionmentioning

confidence: 97%

International Multidisciplinary Consensus Conference on Multimodality Monitoring: Cerebral Metabolism

Hutchinson

O’Phelan²

2014

Neurocrit Care

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Microdialysis is a powerful technique, which enables the chemistry of the extracellular space to be measured directly. Applying this technique to patients in neurointensive care has increased our understanding of the pathophysiology of traumatic brain injury and spontaneous hemorrhage. In parallel, it is important to determine the place of microdialysis in assisting in the management of patients on an individual intention to treat basis. This is made possible by the availability of analyzers which can measure the concentration of glucose, pyruvate, lactate, and glutamate at the bedside. Samples can then be stored for later analysis of other substrate and metabolites e.g., other amino acids and cytokines. The objective of this paper is to review the fundamental literature pertinent to the clinical application of microdialysis in neurointensive care and to give recommendations on how the technique can be applied to assist in patient management and contribute to outcome. A literature search detected 1,933 publications of which 55 were used for data abstraction and analysis. The role of microdialysis was evaluated in three conditions (traumatic brain injury, subarachnoid hemorrhage, and intracerebral hemorrhage) and recommendations focused on three fundamental areas (relationship to outcome, application of microdialysis to guide therapy, and the ability of microdialysis to predict secondary deterioration).

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‘Long’ pressure reactivity index (L-PRx) as a measure of autoregulation correlates with outcome in traumatic brain injury patients

Abstract: L-PRx correlates with the 6-month outcome in TBI patients. Very slow changes of MAP and ICP may contain important autoregulation information. L-PRx may be an alternative algorithm for the estimation of cerebral autoregulation and clinical prognosis.

Cited by 52 publications

References 21 publications

Short pressure reactivity index versus long pressure reactivity index in the management of traumatic brain injury

Short pressure reactivity index versus long pressure reactivity index in the management of traumatic brain injury

Transhemispheric Diaschisis after Unilateral Focal Cerebral Ischemia Reperfusion: A Longitudinal Voxel-Based Study by MRI

International Multidisciplinary Consensus Conference on Multimodality Monitoring: Cerebral Metabolism

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