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Lemaire, Jean‐Jacques; Khalil, T.; Cervenansky, Frédéric; Gindre, G; Boire, Jean-Yves; Bazin, J. E.; Irthum, B.; Chazal, J.

doi:10.1007/s007010200032

Cited by 48 publications

(12 citation statements)

References 98 publications

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“…Recently, ICP variability has also been examined with mathematical tools using e.g. frequency domain approaches, confining the ICP analysis to variations within specified slow-wave ICP frequencies [ 18 ].…”

Section: Discussionmentioning

confidence: 99%

“…ICP variations have generated interest since the development of ICP monitoring in the NIC [17]. Various ICP wave forms have been examined such as Lundberg's type A wave (plateau wave) with amplitudes above 50 mmHg, a duration above 5 min and occurring at a relatively low frequency [18]. Type B waves have a higher frequency at approximately 1-2 waves/min and with a lower amplitude around 5 mmHg.…”

Section: Icpv: Explanatory Variablesmentioning

confidence: 99%

“…These reactions are amplified when the intracranial pressure/volume reserve is reduced. Other explanations are related to cerebral blood flow-metabolism, variations in arterial pCO 2 and rhythmic brainstem oscillations that control the cerebral vessels [17,18,20].…”

Section: Icpv: Explanatory Variablesmentioning

confidence: 99%

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Intracranial pressure variability: relation to clinical outcome, intracranial pressure–volume index, cerebrovascular reactivity and blood pressure variability

Wettervik

Howells

Enblad

et al. 2019

J Clin Monit Comput

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It was recently found in traumatic brain injury (TBI) that ICP variability (ICPV) predicted favorable outcome. We hypothesized that ICPV may depend on intracranial compliance, unstable blood pressure and cerebral vasomotion. In this study, we aimed to further investigate the explanatory variables for ICPV and its relation to outcome. Data from 362 TBI patients were retrospectively analyzed day 2 to 5 post-injury. ICPV was evaluated in three ways. First, variability in the sub-minute time interval (similar to B waves) was calculated as the amplitude of the ICP slow waves using a bandpass filter, limiting the analysis to oscillations of 55 to 15 s (ICP AMP 55-15). The second and third ICPV measures were calculated as the deviation from the mean ICP averaged over 30 min (ICPV-30m) and 4 h (ICPV-4h), respectively. All ICPV measures were associated with a reduced intracranial pressure/volume state (high ICP and RAP) and high blood pressure variability in multiple linear regression analyses. Higher ICPV was associated with better pressure reactivity in the univariate, but not the multiple analyses. All ICPV measures were associated with favorable outcome in univariate analysis, but only ICP AMP 55-15 and ICPV-30m did so in the multiple logistic regression analysis. Higher ICPV can be explained by a reduced intracranial compliance and variations in cerebral blood volume due to the vessel response to unstable blood pressure. As ICP AMP 55-15 and ICPV-30m independently predicted favorable outcome, it may represent general cerebral vessel activity, associated with better cerebral blood flow regulation and less secondary insults.

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Section: Discussionmentioning

confidence: 99%

Section: Icpv: Explanatory Variablesmentioning

confidence: 99%

See 1 more Smart Citation

Intracranial pressure variability: relation to clinical outcome, intracranial pressure–volume index, cerebrovascular reactivity and blood pressure variability

Wettervik

Howells

Enblad

et al. 2019

J Clin Monit Comput

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“…It has also been shown that a change in slow waves of the ICP signal in TBI indicates an autoregulatory response to changes in cerebral perfusion [16]. B-waves have also been shown to occur simultaneously with vascular oscillations in an experimental study with incremental ICP increases [17].…”

Section: Discussionmentioning

confidence: 99%

Impaired cerebrovascular reactivity after acute traumatic brain injury can be detected by wavelet phase coherence analysis of the intracranial and arterial blood pressure signals

Kvandal

Sheppard

Landsverk

et al. 2013

J Clin Monit Comput

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The objective of the study was to evaluate the wavelet spectral energy of oscillations in the intracranial pressure (ICP) signal in patients with acute traumatic brain injury (TBI). The wavelet phase coherence and phase shift in the 0.006–2 Hz interval between the ICP and the arterial blood pressure (ABP) signals were also investigated. Patients were separated into normal or impaired cerebrovascular reactivity, based on the pressure reactivity index (PRx). Spectral energy, phase coherence and phase shift in the low frequency and cardiorespiratory intervals were compared for the two groups. Data were prospectively collected and analyzed retrospectively in 22 patients, within the first week after acute TBI. The ICP and ABP signals were continuously recorded for 40 min and the wavelet transform was used to calculate the spectral energy and phase of the signals. The average ICP wavelet energy spectrum showed distinct peaks around 1.0 (cardiac), 0.25 (respiratory) and 0.03 Hz. Patients with normal cerebrovascular reactivity (negative PRx) had 38.6 % (±SD 16.7 %) of the mean wavelet energy below the lower limit of the respiratory frequency band (0.14 Hz) compared to only 18.1 % (±SD 17.8 %) in patients with altered cerebrovascular reactivity (positive PRx) (difference: p = 0.0057). Wavelet phase coherence between the ABP and ICP signals was statistically significant (p < 0.05) in the 0.006–2 Hz interval. The phase shift between the ABP and ICP signals was around zero in the 0.14–1.0 Hz interval. Seven patients with PRx between −0.4943 and −0.1653 had a phase shift in the interval 0.07–0.14 Hz, whereas 15 patients with PRx between −0.1019 and 0.3881 had a phase shift in the interval 0.006–0.07 Hz. We conclude that the wavelet transform of the ICP signal shows spectral peaks at the cardiac, respiratory and 0.03 Hz frequencies. Normal cerebrovascular reactivity seems to be manifested as increased spectral energy in the frequency interval <0.14 Hz. A phase shift between the ICP and ABP signals in the interval 0.07–0.14 Hz indicates normal cerebrovascular reactivity, while a phase shift in the interval 0.006–0.07 Hz indicates altered cerebrovascular reactivity.

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“…Additionally, the presence of Lundberg A waves, which are sustained sharp increases in mean ICP lasting 5–20 min, may also signify diminishing compliance ( Figure 5 C) [ 55 ]. Lundberg B waves, which are clustered cyclic elevations in ICP occurring at a rate of 0.33–3 cycles per minutes with overall cluster duration of 5–30 min [ 56 , 57 ], are non-specific indicators of diminished compliance as they can also be present in patients with normal ICP [ 55 ].…”

Section: Approaches To Improving Utility Of Invasive Icp Monitorinmentioning

confidence: 99%

Intracranial Pressure Monitoring—Review and Avenues for Development

Harary

Dolmans

Gormley

2018

Sensors

125

110

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Intracranial pressure (ICP) monitoring is a staple of neurocritical care. The most commonly used current methods of monitoring in the acute setting include fluid-based systems, implantable transducers and Doppler ultrasonography. It is well established that management of elevated ICP is critical for clinical outcomes. However, numerous studies show that current methods of ICP monitoring cannot reliably define the limit of the brain’s intrinsic compensatory capacity to manage increases in pressure, which would allow for proactive ICP management. Current work in the field hopes to address this gap by harnessing live-streaming ICP pressure-wave data and a multimodal integration with other physiologic measures. Additionally, there is continued development of non-invasive ICP monitoring methods for use in specific clinical scenarios.

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Untitled

Cited by 48 publications

References 98 publications

Intracranial pressure variability: relation to clinical outcome, intracranial pressure–volume index, cerebrovascular reactivity and blood pressure variability

Intracranial pressure variability: relation to clinical outcome, intracranial pressure–volume index, cerebrovascular reactivity and blood pressure variability

Impaired cerebrovascular reactivity after acute traumatic brain injury can be detected by wavelet phase coherence analysis of the intracranial and arterial blood pressure signals

Intracranial Pressure Monitoring—Review and Avenues for Development

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