Articles: general-anesthesia.
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Mivacurium is a short-acting nondepolarising muscle relaxant of the benzylisoquinoline type undergoing rapid breakdown by plasma cholinesterase. With 2.5 fold ED95, tracheal intubation can be accomplished within 2-3 min following injection. The ensuing DUR 25% (i.e. time from injection to 25% recovery of control twitch tension) is three times as long as with succinylcholine and about half as long as with equipotent doses of atracurium and vecuronium. ⋯ One of them, cis-atracurium, is five times as potent as the chiral mixture while having a similar pharmacodynamic and kinetic profile. It does not cause significant histamine release or clinically relevant cardiovascular effects at doses up to 8 times the ED95. Laudanosine release seems to be less with cis-atracurium than with atracurium.
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As a result of more offensive therapeutic measures and the given abilities of modern medicine and the increasing number of geriatric patients who are characterized by multimorbidity, more perioperative complications, in particular those of cardiac origin, can be expected. As in any other medical discipline, the safety of anaesthesiological care of the patient very much depends on the individual professional qualification and competence of the physician. For the field of anaesthesiology it can be concluded that it is necessary to tackle the specific problems of this risk group in order to reduce the rate of complications to a minimum. ⋯ Three main symptoms--increasing oxygen uptake (as a product of pain or shivering), hypoventilation and hypoxaemia--should be avoided in the postoperative period. Therefore, respiratory insufficiency should be diagnosed without fail by respiratory monitoring. If required, artificial ventilation must be continued, with particular attention being given to circulatory effects during artificial ventilation and weaning from the ventilator.
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This review discusses the mechanism(s) of general anesthesia from a pharmacological viewpoint; in particular, the ability of drugs to produce many different effects is emphasised. The problems of experimental measurement of general anesthesia are discussed, and the possibilities for antagonism and potentiation of anesthesia considered. Physicochemical studies on anesthesia are described, as are the advancement of ideas beyond consideration of lipids and proteins as separate sites of action. The importance of studies on different areas of the brain is highlighted, and the review finishes with a survey of the effects of general anesthetics on synaptic transmission which emphasises the problems of extrapolation from in vitro to in vivo.
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Mivacurium is a potent, short-acting, nondepolarizing relaxant of the benzylisoquinoline series. In adults endotracheal intubation can be performed after a 2 x ED95 dose of 0.15-0.2 mg/kg within 2-2.5 minutes. In infants onset time and clinical duration of mivacurium are significantly shorter than in adults. ⋯ The properties of mivacurium described above are related to patients with normal pseudocholinesterase activity. Particularly patients with atypical pseudocholinesterase show a marked increase in clinical duration. Side-effects due to significant histamine release with flush, tachycardia and hypotension are seldom observed if mivacurium is injected slowly over a period of more than 30 seconds and bolus injections of more than 2 x ED95 or 3 x ED95 are avoided.
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A number of anesthetic agents have significant cerebroprotective potential and alter ischemic tolerance in vivo, at least within specific experimental conditions such as focal or incomplete, global cerebral ischemia. As compared to the unanesthetized state, each of these agents has some influence on CBF and metabolism, and many have significant effects on vascular responses to dilator stimuli. Relevant studies that provide clues to the mechanisms of anesthetic action in brain injury have been reviewed, and it is likely that these mechanisms are multifactorial and may overlap from one class of agents to another. Lastly, there is a clear need for further studies that specifically evaluate the neuroprotective mechanism of each agent, determine the effect on outcomes when the anesthetic is administered only as a posttreatment at clinically relevant concentrations, and compare anesthetics with the unanesthetized state when possible.