Retentissement électroencéphalographique de l'anesthésie au propofol

Quantitative electroencephalographic analysis of the biphasic concentration-effect relationship of propofol in surgical patients during extradural analgesia

“…A biphasic EEG response to increasing blood propofol concentrations was first described by Hazeaux and colleagues, 4 who reported an increase followed by a decrease in alpha amplitude, and the appearance of theta and delta activity after an injection of propofol 2.5 mg kg 91 in 30 s. Borgeat and co-workers 5 described similar changes during induction of anaesthesia in children with a propofol bolus of 3 or 5 mg kg 91 . They found a transient shift from predominantly alpha (9-10 Hz) activity to beta (914 Hz) activity, followed by continuous delta activity.…”

“…This sample site was chosen to minimize patient discomfort. Blood samples of 3 ml were taken at 0, 2,4,6,8,10,12,14,16,18,20,22,25,30,40,55,70,100,130, and 190 min after the start of the propofol infusion and mixed with EDTA. Blood samples were stored at 4 ЊC until determination of whole-blood propofol concentrations with high performance liquid chromatography (detection limit 5 g l 91 , coefficient of variation 4.3%).…”

Meanfield modeling of propofol-induced changes in spontaneous EEG rhythms

“…For propofol concentrations that are commonly used to perform surgical procedures with EEG monitoring, for instance during carotid endarterectomy (van Putten et al, 2004) the anesthesiologist aims to realize a continuous EEG pattern characterized by an enhancement of EEG power with pronounced alpha oscillations. Additional characteristics of the EEG at these concentrations of propofol include an increase in alpha peak-frequency, especially over frontal regions, accompanied by increases in delta and theta power (Feshchenko et al, 2004;Gugino et al, 2001;Hazeaux et al, 1987;San-juan et al, 2010;Schwender et al, 1996). In this study we provide an integrated explanation of the observed frontal alpha oscillations and increases in delta and theta power by adopting a meanfield approach to large-scale brain dynamics.…”

“…These dose-dependent changes of oscillatory activity, with an initial increase at relatively low concentrations, and a subsequent decrease with increasing concentrations, are referred to as bi-phasic responses or induction sequences (Johnson et al, 2003;Kuizenga et al, 2001;San-juan et al, 2010). For increasingly deeper levels of general anesthesia one can observe alpha spindles (Huotari, 2004), burstsuppression patterns, sustained slow waves (Hazeaux et al, 1987), and even iso-electricity (Doyle and Matta, 1999;Lukatch et al, 2005). For propofol concentrations that are commonly used to perform surgical procedures with EEG monitoring, for instance during carotid endarterectomy (van Putten et al, 2004) the anesthesiologist aims to realize a continuous EEG pattern characterized by an enhancement of EEG power with pronounced alpha oscillations.…”

La influencia de la administración de solución de lactato de Ringer o HES 130 / 0,4 en la integridad de la mucosa del intestino delgado en un modelo porcino de hemorragia controlada = The influence of administering Ringer's Lactate solution or HES 130/0.4 on the integrity of the small intestinal mucosa in a pig model of controlled haemorrhage

“…In propofol-based anaesthesia, there is a dose-dependent decrease in the BIS. The administration of low doses of propofol increases the amplitude and the EEG alpha waves rhythm, followed by a shift to EEG gamma and theta frequency and when higher doses are given, there is burst suppression and a decrease of the amplitude of the EEG (Yate et al 1986;Hazeaux et al 1987;Billard et al 1997;Glass et al 1997;Liu et al 1997;Struys et al 1998;Bousoula et al 2003;Bruhn et al 2003;Ellerkmann et al 2006).…”