Publications (32) View all
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Article: Effect of a fluid challenge on the Surgical Pleth Index during stable propofol-remifentanil anaesthesia.
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ABSTRACT: 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. 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) . 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 μg/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. 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.Acta Anaesthesiologica Scandinavica 01/2012; 56(6):787-96. · 2.19 Impact Factor -
Article: Comparison of the surgical Pleth Index™ with haemodynamic variables to assess nociception-anti-nociception balance during general anaesthesia.
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ABSTRACT: 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. 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 µg 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. 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. 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.BJA British Journal of Anaesthesia 11/2010; 106(1):101-11. · 4.24 Impact Factor -
Article: Ventilatory management during routine general anaesthesia.
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ABSTRACT: Intraoperative hypoxaemia and postoperative respiratory complications remain the challenges of modern anaesthetic practice. Anaesthesia causes both depression of respiratory centres and profound changes of respiratory mechanics. Most anaesthetized patients consequently require mechanical ventilation and supplemental oxygen. Recent data suggest that intraoperative respiratory management of a patient can affect postoperative outcome. In this review, we briefly describe the mechanisms responsible for the impairment of intraoperative gas exchange and provide guidelines to prevent or manage hypoxaemia. Moreover, we discuss several aspects of mechanical ventilation that can be employed to improve patients' outcome.European Journal of Anaesthesiology 02/2009; 26(1):1-8. · 2.23 Impact Factor -
Article: What is the outcome of intraoperative management? Reply.
European Journal of Anaesthesiology 05/2009; · 2.23 Impact Factor -
Article: [Contribution of functional neuroimaging studies to the understanding of the mechanisms of general anesthesia].
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ABSTRACT: Since the early beginning of anesthesia, almost 2 centuries ago, ignorance has prevailed regarding the cerebral mechanisms of the loss of consciousness induced by general anesthesia. The recent contribution of functional brain imaging studies has allowed considerable progress in that domain. Similarly, the study of brain function under general anesthesia is currently a major tool for the understanding of conscious phenomena. This functional approach leads to conceptual changes about the functioning brain and may ultimately provide tracks for new treatments and practical applications. All these aspects are reviewed in this paper, at the light of the most recent literature.Revue médicale de Liège 01/2009; 64 Spec No:36-41.
