Efficacy of a combined technique using the Trachlight™ together with direct laryngoscopy under simulated difficult airway conditions in 350 anesthetized patients

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The Dexter® Endoscopic Dexterity Trainer improves fibreoptic bronchoscopy skills: Preliminary observations

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Raman spectroscopy as a tool to determine the thermal maturity of organic matter : application to sedimentary, metamorphic and structural geology

Raman spectrometry is a rapid, non-destructive alternative to conventional tools employed to assess the thermal alteration of organic matter (OM). Raman may be used to determine vitrinite reflectance equivalent OM maturity values for petroleum exploration, to provide temperature data for metamorphic studies, and to determine the maximum temperatures reached in fault zones. To achieve the wider utilisation of Raman, the spectrum processing method, and the positions and nomenclature of Raman bands and parameters, all need to be standardized. We assess the most widely used Raman parameters as well as the best analytical practices that have been proposed. Raman band separation and G-band full-width at half-maximum are the best parameters to estimate the maturity for rocks following diagenesis–metagenesis. For metamorphic studies, the ratios of band areas after performing deconvolution are generally used. Further work is needed on the second-order region, as well as assessing the potential of using integrated areas on the whole spectrum, to increase the calibrated temperature range of Raman parameters. Applying Raman spectroscopy on faults has potential to be able to infer both temperature and deformation processes. We propose a unified terminology for OM Raman bands and parameters that should be adopted in the future. The popular method of fitting several functions to a spectrum is generally unnecessary, as Raman parameters determined from an un-deconvoluted spectrum can track the maturity of OM. To progress the Raman application as a geothermometer a standardized approach must be developed and tested by means of an interlaboratory calibration exercise using reference materials

Rôle de la déformation métamorphique dans la cristallinité du graphite : l'exemple des schistes graphiteux de la vallée de la Lotru (Carpathes, Roumanie)

International audienceThe study of the schists from Lotru valley (Carpathians mountains, Romania) shows the role of stress in graphite crystallinity. The carbonaceous material was separated and studied by X-ray diffraction and Raman microspectrometry. There exists a clear contrast between the crystallization degree of graphite found in the quartz–muscovite schists (good) and that found in the quartzites (poor). This observation is in conformity with a clear differentiation of fabric. The graphite suffered an anisotropic deformation in the graphitic schists, whereas it was protected from deformation by quartz in the quartzites. In this last case, the development of graphite from the organic material took place with a volume decrease, protected by the surrounding quartz.L'étude des schistes graphiteux de la vallée de la Lotru (Carpathes, Roumanie) montre le rôle de la déformation dans la cristallinité du graphite. Le matériel carboné a été étudié par diffractométrie des rayons X et microspectrométrie Raman. On observe un contraste très net entre la cristallinité du graphite dans les schistes à quartz–muscovite, d'une part (bonne cristallinité), et dans les quartzites, d'autre part (mauvaise cristallinité), qui sont séparés par une distance de quelques centimètres. Cette observation se corrèle avec des différences nettes de texture : dans les schistes, le graphite est dans la schistosité et a été soumis à une déformation anisotrope ; dans les quartzites, il a été protégé par le quartz et a moins été soumis à la déformation

Day surgery: the value of monitored anesthesia care and intraoperative monitoring

Day surgery: the value of monitored anesthesia care and intraoperative monitorin

Orbital head pain elicited by neuroendoscopy of the third ventricle performed under local anesthesia

Endoscopic third ventriculostomy (ETVS) is considered a minimally invasive procedure for blocked hydrocephalus. In 24 cases, this procedure was carried out in awake patients under local anesthesia. All patients reported abrupt orbital pain when the third ventricle floor was manipulated. Although recent advancements in knowledge of some forms of migraine and cluster headache could be regarded as a good basis for interpreting the pain triggered by ETVS, other hypotheses should also be taken into consideration

A simplified endoscopic third ventriculostomy under local anesthesia

The aim of this study is the analysis of our experience with awake endoscopic third ventriculostomy (ETVS) in hydrocephalic patients. From September 1994 to December 2001, 24 neuroendoscopic procedures were performed under local anesthesia. Local infiltration was administered using a bupivacaine and lidocaine mixture. Analgesics were titrated to the effect. A free-hand technique with a flexible endoscope was adopted in 24 patients with primitive and secondary (neoplastic) hydrocephalus. ETVS was performed successfully in all cases. No procedure needed to be discontinued due to seizures, bleeding or agitation. Dural incision/coagulation and Fogarty dilatation proved to be the most painful maneuvers requiring, sometimes, supplemental analgesic administration. No intraoperative complications were observed; however, two asymptomatic trajectory hematomas were incidentally discovered two and three days after the operation, respectively. Awake ETVS is a valuable alternative procedure that can be adopted in adult cooperative patients, provided that the procedure is done in an essential and fast way with the free-hand technique, by means of a flexible endoscope, and with the assistance of an anesthesiologist