Agressologie: revue internationale de physio-biologie et de pharmacologie appliquées aux effets de l'agression
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Since Althesin was withdrawn from the market, and since Ledingham's report on the inhibitory effect of etomidate on cortisol secretion, anaesthesia in intracranial surgery has lacked an intravenous agent with a pharmacokinetic-dynamic profile making it a suitable alternative to the classic thiopental-isoflurane sequence. Propofol has been used experimentally in neuroanaesthesia for 4 years, and is now ready to be used on a routine basis in neuroanaesthesia. An induction dose of propofol decreases cerebral blood flow (CBF), cerebral metabolic rate for oxygen (CMR02), and intracranial pressure (ICP). ⋯ Recovery can thus be rapid. Propofol is used with the same agents or manoeuvres as those used with the thiopental-isoflurane sequence, i.e. lidocaine, fentanyl, esmolol, mannitol, steroids, hyperventilation and lumbar drainage in order to obtain the most relaxed brain and reduce the mechanical pressure exerted on the brain. Propofol can be used for all intracranial pathologies with may be one exception, when a cerebral aneurysm has to be clipped and vasospasm is present.
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Knowledge of the influence of anesthetics on cerebral blood flow and metabolism is the key to both safe neuroanesthesia practice and understanding the possible neuroprotection offered by these agents. In this paper the authors summarize recent data from the literature. All volatile anesthetics (except for nitrous oxide) produce a dose dependent decrease in cerebral metabolism. ⋯ Autoregulation is preserved during the administration of propofol. The effects of narcotic agents depend largely on the background anesthetic. Pathological conditions induced physiologic changes, and coadministration of other drugs can greatly alter the effects of anesthetics on the brain.