Der Anaesthesist
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Clinical Trial
[Topographic electroencephalometry following anesthesia induction with ketamine-midazolam].
The neurophysiological action of ketamine has attracted increasing interest in recent years, with special interest in receptor action and in neurophysiological differences between and psychomimetic side effects of the two enantiomorphs. Most of the neurophysiological examinations published deal with ketamine as a single anaesthetic agent, although it has been suggested to that psychomimetic side-effects and haemodynamic deterioration could be avoided by combining ketamine with a sedative drug. The primary aim of our study was to examine the combined ketamine-midazolam action on cerebral activity; secondly, we planned to look at these interactions topographically at different points of the cortex to evaluate topographical differences in the combination's action; thirdly, the cerebral and haemodynamic reactions to anaesthesiological stimuli (intubation, gastric tube) were evaluated and compared. ⋯ Thus, the action of combined ketamine and midazolam on cerebral function is not an additive, but an interactive process. Despite a relatively high induction dosage, haemodynamic changes during intubation occurred and were accompanied by changes in cerebral activity. This can be regarded as incomplete cerebral suppression even by these induction dosages.
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Review Randomized Controlled Trial Clinical Trial
[Medical therapy for coronary heart disease. Perioperative relevance].
The aim of our review is to summarize relevant data on the perioperative use of anti-ischaemic drugs in patients at risk for or with proven coronary heart disease. ⋯ Beta-blockers, calcium channel blockers, nitrates, and possibly alpha 2-agonists lead to reduced rates of PMI and other cardiac complications in risk patients. Current anti-anginal medications, with the exception of anti-platelet agents, should be maintained to the day of surgery and continued as soon as possible thereafter. All of these drugs except anti-platelet agents may also be used intra-operatively, however, possible interactions with anaesthetic agents should be carefully considered.
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Randomized Controlled Trial Comparative Study Clinical Trial
[Ketamine racemate versus S-(+)-ketamine with or without antagonism with physostigmine. A quantitative EEG study on volunteers].
The potency of S-(+)-ketamine is approximately double that of the racemic ketamine. This study was carried out to investigate the recovery of cerebral electrical function after a bolus of 1.3 mg/kg ketamine or 0.65 mg/kg S-(+)-ketamine and subsequent continuous application of 4 mg/kg h ketamine per h or 2 mg/kg S-(+)-ketamine, per h for 15 min. Furthermore, the centrally acting, cholinergic agonist physostigmine has been reported to antagonize ketamine and to shorten the recovery period. ⋯ The spectral edge frequency did not differ between measurement points, and is therefore not suitable for assessment of the depth of anaesthesia reached with ketamine/S-(+)-ketamine. The dose of physostigmine tested was probably too low to produce antagonism of S-(+)-ketamine. An increased dosage of physostigmine has yet to be studied, but is likely to cause a higher rate of side effects, such as nausea, vomiting and bradycardia, and possibly even tonic-clonic seizures.
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Randomized Controlled Trial Comparative Study Clinical Trial
[Psychometric changes as well as analgesic action and cardiovascular adverse effects of ketamine racemate versus s-(+)-ketamine in subanesthetic doses].
The intravenous anaesthetic ketamine is widely used in subanaesthetic doses as a potent analgesic in emergency and disaster medicine. At present, ketamine is commercially available only in its racemic form, although the S(+)-isomer has proved to be approximately three times as potent than the R(-)-isomer. In first clinical trials in Germany, S(+)-ketamine was reported to be markedly advantageous with regard to analgesia in anaesthetized patients. ⋯ S(+)-Ketamine at half-dose of ketamine-racemate is as potent as ketamine-racemate in subanaesthetic doses with powerful analgesic properties. The (+)-isomer exerts less adverse effects on measurable cerebral functions and induces a significantly smaller increase in heart rate. Since states of impaired consciousness and disorientation are especially disturbing under emergency conditions, further investigations should be carried out to define S(+)-ketamine's position as a potent analgesic for therapeutic use in emergency and disaster medicine.
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Randomized Controlled Trial Comparative Study Clinical Trial
[Different opioids in patients at cardiovascular risk. Comparison of central and peripheral hemodynamic adverse effects].
Efficient analgesia may be the major objective in the cardiovascular risk patient following myocardial infarction, acute occlusion of peripheral vessels, or dissection/perforation of major abdominal vessels. It was the purpose of the study to investigate the haemodynamic and respiratory side effects of eight different opioids in 57 circulatory risk patients prior to major vascular surgery. METHODS. ⋯ CONCLUSIONS. For interpretation of the results, factors such as respiratory depression, histamine release, secretion of endogenous catecholamines, and hypoxia-induced pulmonary vasoconstriction have to be discussed. Tramadol, an opioid with moderate potency, seems to offer some advantages due to its minor cardiovascular and respiratory side effects.