References of "BONHOMME, Vincent"
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See detailPreoperative Adherence to Continuous Positive Airway Pressure among Obstructive Sleep Apnea Patients
Deflandre; Degey, S; BONHOMME, Vincent ULg et al

in Minerva Anestesiologica (in press)

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See detailPhysiological Signal Processing for Individualized Anti-nociception Management During General Anesthesia: a Review.
De Jonckheere, J.; Bonhomme, Vincent ULg; Jeanne, M. et al

in Yearbook of medical informatics (2015), 10(1), 95-101

OBJECTIVE: The aim of this paper is to review existing technologies for the nociception / anti-nociception balance evaluation during surgery under general anesthesia. METHODS: General anesthesia combines ... [more ▼]

OBJECTIVE: The aim of this paper is to review existing technologies for the nociception / anti-nociception balance evaluation during surgery under general anesthesia. METHODS: General anesthesia combines the use of analgesic, hypnotic and muscle-relaxant drugs in order to obtain a correct level of patient non-responsiveness during surgery. During the last decade, great efforts have been deployed in order to find adequate ways to measure how anesthetic drugs affect a patient's response to surgical nociception. Nowadays, though some monitoring devices allow obtaining information about hypnosis and muscle relaxation, no gold standard exists for the nociception / anti-nociception balance evaluation. Articles from the PubMed literature search engine were reviewed. As this paper focused on surgery under general anesthesia, articles about nociception monitoring on conscious patients, in post-anesthesia care unit or in intensive care unit were not considered. RESULTS: In this article, we present a review of existing technologies for the nociception / anti-nociception balance evaluation, which is based in all cases on the analysis of the autonomous nervous system activity. Presented systems, based on sensors and physiological signals processing algorithms, allow studying the patients' reaction regarding anesthesia and surgery. CONCLUSION: Some technological solutions for nociception / antinociception balance monitoring were described. Though presented devices could constitute efficient solutions for individualized anti-nociception management during general anesthesia, this review of current literature emphasizes the fact that the choice to use one or the other mainly relies on the clinical context and the general purpose of the monitoring. [less ▲]

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See detailAdherence to Continuous Positive Airway Pressure (CPAP) Therapy
Deflandre, Eric ULg; Degey, Stéphanie; BONHOMME, Vincent ULg et al

Poster (2014, October)

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See detailAdherence to Continuous Positive Airway Pressure (CPAP) Therapy
Deflandre, Eric ULg; Degey, Stéphanie; BONHOMME, Vincent ULg et al

Poster (2014, October)

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See detailPosterior Cingulate Cortex-Related Co-Activation Patterns: A Resting State fMRI Study in Propofol-Induced Loss of Consciousness
Amico, Enrico ULg; Gomez, Francisco; Di Perri, Carol et al

in PLoS ONE (2014), 9

Background: Recent studies have been shown that functional connectivity of cerebral areas is not a static phenomenon, but exhibits spontaneous fluctuations over time. There is evidence that fluctuating ... [more ▼]

Background: Recent studies have been shown that functional connectivity of cerebral areas is not a static phenomenon, but exhibits spontaneous fluctuations over time. There is evidence that fluctuating connectivity is an intrinsic phenomenon of brain dynamics that persists during anesthesia. Lately, point process analysis applied on functional data has revealed that much of the information regarding brain connectivity is contained in a fraction of critical time points of a resting state dataset. In the present study we want to extend this methodology for the investigation of resting state fMRI spatial pattern changes during propofol-induced modulation of consciousness, with the aim of extracting new insights on brain networks consciousness-dependent fluctuations. Methods: Resting-state fMRI volumes on 18 healthy subjects were acquired in four clinical states during propofol injection: wakefulness, sedation, unconsciousness, and recovery. The dataset was reduced to a spatio-temporal point process by selecting time points in the Posterior Cingulate Cortex (PCC) at which the signal is higher than a given threshold (i.e., BOLD intensity above 1 standard deviation). Spatial clustering on the PCC time frames extracted was then performed (number of clusters = 8), to obtain 8 different PCC co-activation patterns (CAPs) for each level of consciousness. Results: The current analysis shows that the core of the PCC-CAPs throughout consciousness modulation seems to be preserved. Nonetheless, this methodology enables to differentiate region-specific propofol-induced reductions in PCC-CAPs, some of them already present in the functional connectivity literature (e.g., disconnections of the prefrontal cortex, thalamus, auditory cortex), some others new (e.g., reduced co-activation in motor cortex and visual area). Conclusion: In conclusion, our results indicate that the employed methodology can help in improving and refining the characterization of local functional changes in the brain associated to propofol-induced modulation of consciousness. [less ▲]

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See detailAdherence to Continuous Positive Airway Pressure (CPAP) Therapy
Deflandre, Eric ULg; Degey, Stéphanie; BONHOMME, Vincent ULg et al

in CHEST (2014, March), 145

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See detailInteret de la surveillance et de l'analyse de l'electroencephalogramme au cours de l'anesthesie.
Kalin, S.; Bonhomme, Vincent ULg

in Revue medicale de Liege (2014), 69 Spec No

Electroencephalography (EEG) records brain electrical activity at the scalp level. As a functional and non invasive witness of brain activity, EEG has long raised the interest of researchers and ... [more ▼]

Electroencephalography (EEG) records brain electrical activity at the scalp level. As a functional and non invasive witness of brain activity, EEG has long raised the interest of researchers and practitioners, notably in the domain of anesthesia. Thanks to technical advances, this complex signal can now be dissected, and a huge amount of information can be extracted from it. This information gives the opportunity to quantify theeffects of general anesthesia on the brain, and provides a better understanding of the underlying mechanisms. [less ▲]

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See detailPreeclampsia: an update.
LAMBERT, Géraldine ULg; BRICHANT, Jean-François ULg; Hartstein, Gary ULg et al

in Acta anaesthesiologica Belgica (2014), 65(4), 137-49

Preeclampsia was formerly defined as a multisystemic disorder characterized by new onset of hypertension (i.e. systolic blood pressure (SBP) >/= 140 mmHg and/or diastolic blood pressure (DBP) >/= 90 mmHg ... [more ▼]

Preeclampsia was formerly defined as a multisystemic disorder characterized by new onset of hypertension (i.e. systolic blood pressure (SBP) >/= 140 mmHg and/or diastolic blood pressure (DBP) >/= 90 mmHg) and proteinuria (> 300 mg/24 h) arising after 20 weeks of gestation in a previously normotensive woman. Recently, the American College of Obstetricians and Gynecologists has stated that proteinuria is no longer required for the diagnosis of preeclampsia. This complication of pregnancy remains a leading cause of maternal morbidity and mortality. Clinical signs appear in the second half of pregnancy, but initial pathogenic mechanisms arise much earlier. The cytotrophoblast fails to remodel spiral arteries, leading to hypoperfusion and ischemia of the placenta. The fetal consequence is growth restriction. On the maternal side, the ischemic placenta releases factors that provoke a generalized maternal endothelial dysfunction. The endothelial dysfunction is in turn responsible for the symptoms and complications of preeclampsia. These include hypertension, proteinuria, renal impairment, thrombocytopenia, epigastric pain, liver dysfunction, hemolysis-elevated liver enzymes-low platelet count (HELLP) syndrome, visual disturbances, headache, and seizures. Despite a better understanding of preeclampsia pathophysiology and maternal hemodynamic alterations during preeclampsia, the only curative treatment remains placenta and fetus delivery. At the time of diagnosis, the initial objective is the assessment of disease severity. Severe hypertension (SBP >/= 160 mm Hg and/or DBP >/= 110 mmHg), thrombocytopenia < 100.000/muL, liver transaminases above twice the normal values, HELLP syndrome, renal failure, persistent epigastric or right upper quadrant pain, visual or neurologic symptoms, and acute pulmonary edema are all severity criteria. Medical treatment depends on the severity of preeclampsia, and relies on antihypertensive medications and magnesium sulfate. Medical treatment does not alter the course of the disease, but aims at preventing the occurrence of intracranial hemorrhages and seizures. The decision of terminating pregnancy and perform delivery is based on gestational age, maternal and fetal conditions, and severity of preeclampsia. Delivery is proposed for patients with preeclampsia without severe features after 37 weeks of gestation and in case of severe preeclampsia after 34 weeks of gestation. Between 24 and 34 weeks of gestation, conservative management of severe preeclampsia may be considered in selected patients. Antenatal corticosteroids should be administered to less than 34 gestation week preeclamptic women to promote fetal lung maturity. Termination of pregnancy should be discussed if severe preeclampsia occurs before 24 weeks of gestation. Maternal end organ dysfunction and non-reassuring tests of fetal well-being are indications for delivery at any gestational age. Neuraxial analgesia and anesthesia are, in the absence of thrombocytopenia, strongly considered as first line anesthetic techniques in preeclamptic patients. Airway edema and tracheal intubation-induced elevation in blood pressure are important issues of general anesthesia in those patients. The major adverse outcomes associated with preeclampsia are related to maternal central nervous system hemorrhage, hepatic rupture, and renal failure. Preeclampsia is also a risk factor for developing cardiovascular disease later in life, and therefore mandates long-term follow-up. [less ▲]

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See detailHow electroencephalography serves the anesthesiologist.
Marchant, Nicolas ULg; Sanders, Robert; Sleigh, Jamie et al

in Clinical EEG and neuroscience (2014), 45(1), 22-32

Major clinical endpoints of general anesthesia, such as the alteration of consciousness, are achieved through effects of anesthetic agents on the central nervous system, and, more precisely, on the brain ... [more ▼]

Major clinical endpoints of general anesthesia, such as the alteration of consciousness, are achieved through effects of anesthetic agents on the central nervous system, and, more precisely, on the brain. Historically, clinicians and researchers have always been interested in quantifying and characterizing those effects through recordings of surface brain electrical activity, namely electroencephalography (EEG). Over decades of research, the complex signal has been dissected to extract its core substance, with significant advances in the interpretation of the information it may contain. Methodological, engineering, statistical, mathematical, and computer progress now furnishes advanced tools that not only allow quantification of the effects of anesthesia, but also shed light on some aspects of anesthetic mechanisms. In this article, we will review how advanced EEG serves the anesthesiologist in that respect, but will not review other intraoperative utilities that have no direct relationship with consciousness, such as monitoring of brain and spinal cord integrity. We will start with a reminder of anesthestic effects on raw EEG and its time and frequency domain components, as well as a summary of the EEG analysis techniques of use for the anesthesiologist. This will introduce the description of the use of EEG to assess the depth of the hypnotic and anti-nociceptive components of anesthesia, and its clinical utility. The last part will describe the use of EEG for the understanding of mechanisms of anesthesia-induced alteration of consciousness. We will see how, eventually in association with transcranial magnetic stimulation, it allows exploring functional cerebral networks during anesthesia. We will also see how EEG recordings during anesthesia, and their sophisticated analysis, may help corroborate current theories of mental content generation. [less ▲]

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See detailChanges in Effective Connectivity by Propofol Sedation
Gomez Jaramillo, Francisco Albeiro ULg; Phillips, Christophe ULg; Soddu, Andrea ULg et al

in PLoS ONE (2013), 8(8), 71370

Mechanisms of propofol-induced loss of consciousness remain poorly understood. Recent fMRI studies have shown decreases in functional connectivity during unconsciousness induced by this anesthetic agent ... [more ▼]

Mechanisms of propofol-induced loss of consciousness remain poorly understood. Recent fMRI studies have shown decreases in functional connectivity during unconsciousness induced by this anesthetic agent. Functional connectivity does not provide information of directional changes in the dynamics observed during unconsciousness. The aim of the present study was to investigate, in healthy humans during an auditory task, the changes in effective connectivity resulting from propofol induced loss of consciousness. We used Dynamic Causal Modeling for fMRI (fMRI-DCM) to assess how causal connectivity is influenced by the anesthetic agent in the auditory system. Our results suggest that the dynamic observed in the auditory system during unconsciousness induced by propofol, can result in a mixture of two effects: a local inhibitory connectivity increase and a decrease in the effective connectivity in sensory cortices. [less ▲]

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See detailThalamus, Brainstem and Salience Network Connectivity Changes During Propofol-Induced Sedation and Unconsciousness
Guldenmund, Justus Pieter ULg; Demertzi, Athina ULg; BOVEROUX, Pierre ULg et al

in Brain connectivity (2013), 3

In this functional magnetic resonance imaging study, we examined the effect of mild propofol sedation and propofol-induced unconsciousness on resting state brain connectivity, using graph analysis based ... [more ▼]

In this functional magnetic resonance imaging study, we examined the effect of mild propofol sedation and propofol-induced unconsciousness on resting state brain connectivity, using graph analysis based on independent component analysis and a classical seed-based analysis. Contrary to previous propofol research, which mainly emphasized the importance of connectivity in the default mode network (DMN) and external control network (ECN), we focused on the salience network, thalamus, and brainstem. The importance of these brain regions in brain arousal and organization merits a more detailed examination of their connectivity response to propofol. We found that the salience network disintegrated during propofol-induced unconsciousness. The thalamus decreased connectivity with the DMN, ECN, and salience network, while increasing connectivity with sensorimotor and auditory/insular cortices. Brainstem regions disconnected from the DMN with unconsciousness, while the pontine tegmental area increased connectivity with the insulae during mild sedation. These findings illustrate that loss of consciousness is associated with a wide variety of decreases and increases of both cortical and subcortical connectivity. It furthermore stresses the necessity of also examining resting state connectivity in networks representing arousal, not only those associated with awareness. [less ▲]

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See detailObservance au traitement par CPAP chez les patients souffrant d’apnées du sommeil
Deflandre, Eric ULg; DEGEY, Stéphanie; BONHOMME, Vincent ULg et al

Poster (2012, September 20)

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See detailNeural correlates of consciousness during general anesthesia using functional magnetic resonance imaging (fMRI).
BONHOMME, Vincent ULg; Boveroux, Pierre; Brichant, Jean-François ULg et al

in Archives italiennes de biologie (2012), 150(2-3), 155-63

This paper reviews the current knowledge about the mechanisms of anesthesia-induced alteration of consciousness. It is now evident that hypnotic anesthetic agents have specific brain targets whose ... [more ▼]

This paper reviews the current knowledge about the mechanisms of anesthesia-induced alteration of consciousness. It is now evident that hypnotic anesthetic agents have specific brain targets whose function is hierarchically altered in a dose-dependent manner. Higher order networks, thought to be involved in mental content generation, as well as sub-cortical networks involved in thalamic activity regulation seems to be affected first by increasing concentrations of hypnotic agents that enhance inhibitory neurotransmission. Lower order sensory networks are preserved, including thalamo-cortical connectivity into those networks, even at concentrations that suppress responsiveness, but cross-modal sensory interactions are inhibited. Thalamo-cortical connectivity into the consciousness networks decreases with increasing concentrations of those agents, and is transformed into an anti-correlated activity between the thalamus and the cortex for the deepest levels of sedation, when the subject is non responsive. Future will tell us whether these brain function alterations are also observed with hypnotic agents that mainly inhibit excitatory neurotransmission. The link between the observations made using fMRI and the identified biochemical targets of hypnotic anesthetic agents still remains to be identified. [less ▲]

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See detailConnectivity changes underlying spectral EEG changes during propofol-induced loss of consciousness.
Boly, Mélanie ULg; Moran, Rosalyn; Murphy, Michael et al

in The Journal of neuroscience : the official journal of the Society for Neuroscience (2012), 32(20), 7082-90

The mechanisms underlying anesthesia-induced loss of consciousness remain a matter of debate. Recent electrophysiological reports suggest that while initial propofol infusion provokes an increase in fast ... [more ▼]

The mechanisms underlying anesthesia-induced loss of consciousness remain a matter of debate. Recent electrophysiological reports suggest that while initial propofol infusion provokes an increase in fast rhythms (from beta to gamma range), slow activity (from delta to alpha range) rises selectively during loss of consciousness. Dynamic causal modeling was used to investigate the neural mechanisms mediating these changes in spectral power in humans. We analyzed source-reconstructed data from frontal and parietal cortices during normal wakefulness, propofol-induced mild sedation, and loss of consciousness. Bayesian model selection revealed that the best model for explaining spectral changes across the three states involved changes in corticothalamic interactions. Compared with wakefulness, mild sedation was accounted for by an increase in thalamic excitability, which did not further increase during loss of consciousness. In contrast, loss of consciousness per se was accompanied by a decrease in backward corticocortical connectivity from frontal to parietal cortices, while thalamocortical connectivity remained unchanged. These results emphasize the importance of recurrent corticocortical communication in the maintenance of consciousness and suggest a direct effect of propofol on cortical dynamics. [less ▲]

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See detailEffect of a fluid challenge on the Surgical Pleth Index during stable propofol-remifentanil anaesthesia.
Hans, Pol; VERSCHEURE, Sara ULg; Uutela, K. et al

in Acta Anaesthesiologica Scandinavica (2012), 56(6), 787-96

BACKGROUND: The Surgical Pleth Index (SPI), derived from pulse amplitude and heartbeat interval, is proposed to monitor anti-nociception during anaesthesia. Its response to noxious stimulation can be ... [more ▼]

BACKGROUND: The Surgical Pleth Index (SPI), derived from pulse amplitude and heartbeat interval, is proposed to monitor anti-nociception during anaesthesia. Its response to noxious stimulation can be affected by the intravascular volume status. This study investigated the effect of a fluid challenge (FC) on SPI during steady-state conditions. METHODS: After Institutional Review Board approval, 33 consenting patients undergoing neurosurgery received a 4 ml/kg starch FC over less than 5 min under stable surgical stimulation conditions and stable propofol (Ce(PPF) ) and remifentanil (Ce(REMI) ) effect-site concentrations as estimated by target-controlled infusion systems. Intravascular volume status was assessed using the Delta Down (DD). We looked at the SPI response to FC according to DD, Ce(PPF) , and Ce(REMI) . RESULTS: Following FC, SPI did not change in 16, increased in 12, and decreased in 3 patients. Ce(REMI) poorly affected the SPI response to FC. In normovolaemic patients, the probability of an SPI change after FC was low under common Ce(PPF) (0.9 to 3.9 mug/ml). A decrease in SPI was more probable with worsening hypovolaemia and lowering Ce(PPF) , while an increase in SPI was more probable with increasing Ce(PPF) . SPI changes were only attributable to modifications in pulse wave amplitude and not in heart rate. CONCLUSIONS: During stable anaesthesia and surgery, SPI may change in response to FC. The effect of FC on SPI is influenced by volaemia and Ce(PPF) through pulse wave amplitude modifications. These situations may confound the interpretation of SPI as a surrogate measure of the nociception-anti-nociception balance. [less ▲]

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See detailComparison of the Surgical Pleth Index (TM) with haemodynamic variables to assess nociception-anti-nociception balance during general anaesthesia
Bonhomme, Vincent ULg; Uutela, K.; Hans, Grégory ULg et al

in British Journal of Anaesthesia (2011), 106(1), 101-11

BACKGROUND: The Surgical Pleth Index (SPI) is proposed as a means to assess the balance between noxious stimulation and the anti-nociceptive effects of anaesthesia. In this study, we compared SPI, mean ... [more ▼]

BACKGROUND: The Surgical Pleth Index (SPI) is proposed as a means to assess the balance between noxious stimulation and the anti-nociceptive effects of anaesthesia. In this study, we compared SPI, mean arterial pressure (MAP), and heart rate (HR) as a means of assessing this balance. METHODS: We studied a standard stimulus [head-holder insertion (HHI)] and varying remifentanil concentrations (CeREMI) in a group of patients undergoing neurosurgery. Patients receiving target-controlled infusions were randomly assigned to one of the three CeREMI (2, 4, or 6 ng m(1)), whereas propofol target was fixed at 3 microg ml(1). Steady state for both targets was achieved before HHI. Intravascular volume status (IVS) was evaluated using respiratory variations in arterial pressure. Prediction probability (Pk) and ordinal regression were used to assess SPI, MAP, and HR performance at indicating CeREMI, and the influence of IVS and chronic treatment for high arterial pressure, as possible confounding factors. RESULTS: The maximum SPI, MAP, or HR observed after HHI correctly indicated CeREMI in one of the two patients [accurate prediction rate (APR)=0.5]. When IVS and chronic treatment for high arterial pressure were taken into account, the APR was 0.6 for each individual variable and 0.8 when all of them predicted the same CeREMI. That increase in APR paralleled an increase in Pk from 0.63 to 0.89. CONCLUSIONS: SPI, HR, and MAP are of comparable value at gauging noxious stimulation-CeREMI balance. Their interpretation is improved by taking account of IVS, treatment for chronic high arterial pressure, and concordance between their predictions. [less ▲]

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See detailLinking sleep and general anesthesia mechanisms: this is no walkover
BONHOMME, Vincent ULg; BOVEROUX, Pierre ULg; Vanhaudenhuyse, Audrey ULg et al

in Acta Anaesthesiologica Belgica (2011), 62(3), 161-171

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