References of "BONHOMME, Vincent"
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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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See detailMaintaining the communication and information tool of the Belgian anesthesiology community
BONHOMME, Vincent ULg

in Acta Anaesthesiologica Belgica (2011), 62(4), 173-174

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See detailInfluence of anesthesia on cerebral blood flow, cerebral metabolic rate, and brain functional connectivity.
BONHOMME, Vincent ULg; BOVEROUX, Pierre ULg; HANS, Pol ULg et al

in Current Opinion in Anaesthesiology (2011), 24(5), 474-9

PURPOSE OF REVIEW: To describe recent studies exploring brain function under the influence of hypnotic anesthetic agents, and their implications on the understanding of consciousness physiology and ... [more ▼]

PURPOSE OF REVIEW: To describe recent studies exploring brain function under the influence of hypnotic anesthetic agents, and their implications on the understanding of consciousness physiology and anesthesia-induced alteration of consciousness. RECENT FINDINGS: Cerebral cortex is the primary target of the hypnotic effect of anesthetic agents, and higher-order association areas are more sensitive to this effect than lower-order processing regions. Increasing concentration of anesthetic agents progressively attenuates connectivity in the consciousness networks, while connectivity in lower-order sensory and motor networks is preserved. Alteration of thalamic sub-cortical regulation could compromise the cortical integration of information despite preserved thalamic activation by external stimuli. At concentrations producing unresponsiveness, the activity of consciousness networks becomes anticorrelated with thalamic activity, while connectivity in lower-order sensory networks persists, although with cross-modal interaction alterations. SUMMARY: Accumulating evidence suggests that hypnotic anesthetic agents disrupt large-scale cerebral connectivity. This would result in an inability of the brain to generate and integrate information, while external sensory information is still processed at a lower order of complexity. [less ▲]

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See detailUnexpected entropy response to saline spraying at the end of posterior fossa surgery: a few cases report.
Clanet, Matthieu; BONHOMME, Vincent ULg; Lhoest, L. et al

in Acta anaesthesiologica Belgica (2011), 62(2), 87-90

The Spectral Entropy proposed to monitor the depth of anesthesia includes the State Entropy (SE) computed from the EEG (0.8-32 Hz frequency band), and the Response Entropy (RE) computed from EEG and ... [more ▼]

The Spectral Entropy proposed to monitor the depth of anesthesia includes the State Entropy (SE) computed from the EEG (0.8-32 Hz frequency band), and the Response Entropy (RE) computed from EEG and facial muscles activity (0.5-47 Hz frequency band). We report an unexpected Entropy response to saline spraying at the end of posterior fossa surgery. Six patients undergoing scheduled functional surgery of the posterior fossa were included in this report. They were anesthetized with propofol and remifentanil using TCI and received an intubation dose of rocuronium. At the end of surgery, saline spraying, performed for hemostatic purpose and wreckage elimination, resulted in a sustained increase in RE and SE without hemodynamic modification in four patients, while no change was observed in the two other ones. In one of the responding patients, 0.1 mg kg(-1) rocuronium attenuated the Entropy response. In the two non responders, repetition of spraying or rocuronium administration did not change Entropy value. Recovery from anesthesia was comparable in all patients and none of them complained from awareness. We conclude that Entropy can increase during posterior fossa surgery in non-paralyzed patients. This response probably reflects an increase in facial muscle activity rather than a change in depth of anesthesia, as far as it can be attenuated by a small dose of rocuronium. While this hypothesis requires further investigation, these observations suggest that saline spraying may confound interpretation of Entropy during posterior fossa surgery. [less ▲]

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See detailIntravenous lidocaine infusion reduces bispectral index-guided requirements of propofol only during surgical stimulation.
Hans, Grégory ULg; Lauwick, Séverine ULg; Kaba, Abdourahmane ULg et al

in British Journal of Anaesthesia (2010), 105(4), 471-9

BACKGROUND: I.V. lidocaine reduces volatile anaesthetics requirements during surgery. We hypothesized that lidocaine would also reduce propofol requirements during i.v. anaesthesia. METHODS: A randomized ... [more ▼]

BACKGROUND: I.V. lidocaine reduces volatile anaesthetics requirements during surgery. We hypothesized that lidocaine would also reduce propofol requirements during i.v. anaesthesia. METHODS: A randomized controlled study of 40 patients tested the effect of i.v. lidocaine (1.5 mg kg(-1) then 2 mg kg(-1) h(-1)) on propofol requirements. Anaesthesia was maintained with remifentanil and propofol target-controlled infusions (TCI) to keep the bispectral index (BIS) around 50. Effect-site concentrations of propofol and remifentanil and BIS values were recorded before and after skin incision. Data were analysed using anova and mixed effects analysis with NONMEM. Two dose-response studies were then performed with and without surgical stimulation. Propofol TCI titrated to obtain a BIS around 50 was kept constant. Then patients were randomized into four groups: A, saline; B, 0.75 mg kg(-1) bolus then infusion 1 mg kg(-1) h(-1); C, 1.5 mg kg(-1) bolus and infusion 2 mg kg(-1) h(-1); and D, 3 mg kg(-1) bolus and infusion 4 mg kg(-1) h(-1). Lidocaine administration coincided with skin incision. BIS values and haemodynamic variables were recorded. Data were analysed using linear regression and two-way anova. RESULTS: Lidocaine decreased propofol requirements (P<0.05) only during surgery. In the absence of surgical stimulation, lidocaine did not affect BIS nor haemodynamic variables, whereas it reduced BIS increase (P=0.036) and haemodynamic response (P=0.006) secondary to surgery. CONCLUSIONS: The sparing effect of lidocaine on anaesthetic requirements seems to be mediated by an anti-nociceptive action. [less ▲]

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See detailHigh-order brain networks connectivity reflects the level of consciousness during anesthesia
MORAD, O.; BOVEROUX, P.; BONHOMME, Vincent ULg et al

Conference (2010)

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See detailBreakdown of within- and between-network resting state functional magnetic resonance imaging connectivity during propofol-induced loss of consciousness.
Boveroux, Pierre ULg; Vanhaudenhuyse, Audrey ULg; Bruno, Marie-Aurélie ULg et al

in Anesthesiology (2010), 113(5), 1038-53

BACKGROUND: Mechanisms of anesthesia-induced loss of consciousness remain poorly understood. Resting-state functional magnetic resonance imaging allows investigating whole-brain connectivity changes ... [more ▼]

BACKGROUND: Mechanisms of anesthesia-induced loss of consciousness remain poorly understood. Resting-state functional magnetic resonance imaging allows investigating whole-brain connectivity changes during pharmacological modulation of the level of consciousness. METHODS: Low-frequency spontaneous blood oxygen level-dependent fluctuations were measured in 19 healthy volunteers during wakefulness, mild sedation, deep sedation with clinical unconsciousness, and subsequent recovery of consciousness. RESULTS: Propofol-induced decrease in consciousness linearly correlates with decreased corticocortical and thalamocortical connectivity in frontoparietal networks (i.e., default- and executive-control networks). Furthermore, during propofol-induced unconsciousness, a negative correlation was identified between thalamic and cortical activity in these networks. Finally, negative correlations between default network and lateral frontoparietal cortices activity, present during wakefulness, decreased proportionally to propofol-induced loss of consciousness. In contrast, connectivity was globally preserved in low-level sensory cortices, (i.e., in auditory and visual networks across sedation stages). This was paired with preserved thalamocortical connectivity in these networks. Rather, waning of consciousness was associated with a loss of cross-modal interactions between visual and auditory networks. CONCLUSIONS: Our results shed light on the functional significance of spontaneous brain activity fluctuations observed in functional magnetic resonance imaging. They suggest that propofol-induced unconsciousness could be linked to a breakdown of cerebral temporal architecture that modifies both within- and between-network connectivity and thus prevents communication between low-level sensory and higher-order frontoparietal cortices, thought to be necessary for perception of external stimuli. They emphasize the importance of thalamocortical connectivity in higher-order cognitive brain networks in the genesis of conscious perception. [less ▲]

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See detailSide effects of the addition of clonidine 75 microg or sufentanil 5 microg to 0.2% ropivacaine for labour epidural analgesia.
Dewandre, Pierre-Yves ULg; Decurninge, Valérie; Bonhomme, Vincent ULg et al

in International Journal of Obstetric Anesthesia (2010), 19(2), 149-54

BACKGROUND: Sufentanil 5 microg and clonidine 75 microg produce a similar reduction in minimum local anaesthetic concentration of ropivacaine. The aim of the present study was to compare the side effects ... [more ▼]

BACKGROUND: Sufentanil 5 microg and clonidine 75 microg produce a similar reduction in minimum local anaesthetic concentration of ropivacaine. The aim of the present study was to compare the side effects of two equianalgesic solutions by combining 0.2% ropivacaine with either sufentanil 5 microg or clonidine 75 microg for labour epidural analgesia. METHODS: In a prospective double-blind study, 60 women at 5 cm cervical dilatation were randomly allocated to receive 0.2% ropivacaine with either sufentanil 5 microg or clonidine 75 microg to initiate labour analgesia. The analgesic efficacy and side effects of the two mixtures were compared. RESULTS: Onset, duration and quality of analgesia and subsequent ropivacaine consumption were similar in the two groups. Hypotension was significantly more frequent and severe with clonidine than with sufentanil (systolic blood pressure <100 mmHg: 17/26 vs. 6/24, P <0.05; systolic blood pressure <90 mmHg: 5/26 vs. 0/24, P <0.05) resulting in more frequent ephedrine administration (11/26 vs. 2/24, P <0.05) and larger fluid requirements (1696 +/- 583 mL vs. 1264 +/- 407 mL, P < 0.05). Conversely, pruritus was more frequent with sufentanil than with clonidine (6/26 vs. 1/24, P <0.05). CONCLUSIONS: Hypotension occurs more frequently when clonidine is added to epidural ropivacaine instead of an equianalgesic dose of sufentanil. Therefore, clonidine cannot be recommended for routine administration for labour epidural analgesia. [less ▲]

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See detailIntracranial subdural hematoma following spinal anesthesia: case report and review of the literature
Machurot, P. Y.; Vergnion, M.; Fraipont, V. et al

in Acta Anaesthesiologica Belgica (2010), 61(2), 63-66

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See detailEffect of an intravenous infusion of lidocaine on cisatracurium-induced neuromuscular block duration: a randomized-controlled trial.
Hans, Grégory ULg; Defresne, Aline ULg; Ki, Bertille et al

in Acta Anaesthesiologica Scandinavica (2010), 54(10), 1192-6

BACKGROUND: Intravenous lidocaine can be used intraoperatively for its analgesic and antihyperalgesic properties but local anaesthetics may also prolong the duration of action of neuromuscular blocking ... [more ▼]

BACKGROUND: Intravenous lidocaine can be used intraoperatively for its analgesic and antihyperalgesic properties but local anaesthetics may also prolong the duration of action of neuromuscular blocking agents. We hypothesized that intravenous lidocaine would prolong the time to recovery of neuromuscular function after cisatracurium. METHODS: Forty-two patients were enrolled in this randomized, double-blind, placebo-controlled study. Before induction, patients were administered either a 1.5 mg/kg bolus of intravenous lidocaine followed by a 2 mg/kg/h infusion or an equal volume of saline. Anaesthesia was induced and maintained using propofol and remifentanil infusions. After loss of consciousness, a 0.15 mg/kg bolus of cisatracurium was administered. No additional cisatracurium injection was allowed. Neuromuscular function was assessed every 20 s using kinemyography. The primary endpoint was the time to spontaneous recovery of a train-of-four (TOF) ratio >/= 0.9. RESULTS: The time to spontaneous recovery of a TOF ratio >/= 0.9 was 94 +/- 15 min in the control group and 98 +/- 16 min in the lidocaine group (P=0.27). CONCLUSIONS: No significant prolongation of spontaneous recovery of a TOF ratio >/= 0.9 after cisatracurium was found in patients receiving intravenous lidocaine. [less ▲]

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See detailPerioperative management of a child with von Willebrand disease undergoing surgical repair of craniosynostosis: looking at unusual targets.
Maquoi, Isabelle ULg; Bonhomme, Vincent ULg; Born, Jacques Daniel et al

in Anesthesia and Analgesia (2009), 109(3), 720-4

We report the successful management of a craniosynostosis repair in a child with severe Type I von Willebrand disease diagnosed during the preoperative assessment and treated by coagulation factor VIII ... [more ▼]

We report the successful management of a craniosynostosis repair in a child with severe Type I von Willebrand disease diagnosed during the preoperative assessment and treated by coagulation factor VIII and ristocetin cofactor. Collaboration among the anesthesiologist, the neurosurgeon, the clinical pathologist, and the pediatric hematologist is important for successful management. [less ▲]

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