Der Anaesthesist
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The need for better anaesthetic agents has led to the approval or the clinical studies of new compounds, which have or are assumed to have a higher degree of controllability or an improved spectrum of undesired side effects compared to other approved anaesthetics. For the i.v.-anaesthetics, different approaches have been used to achieve this. Among these are the new synthesis of a new chemical entity (NCE), the isolation of an isomer of a racemic mixture and the new galenic preparation of a known substance for i.v.-application. ⋯ After more than 16 years of research and development in the field of Target-Controlled Infusions (TCI), there has been recently introduced the so called Diprifusor-TCI, as a commercially available software module to control the delivery of propofol. TCI uses established pharmacokinetic data to determine infusion rates to achieve desired drug concentrations serving as the target, which can be chosen interactively. This way of dosing i.v. anesthetics is obviously not restricted to one specific compound but can be applied to any i.v.-drug if appropriate pharmacokinetic data are used.
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Randomized Controlled Trial Comparative Study Clinical Trial
[Comparison of sufentanil-propofol-anesthesia with fentanyl-propofol in major abdominal surgery].
Major abdominal surgery often leads to a marked sympathoadrenal stress response with high concentrations of plasma catecholomines, hypertension, and tachycardia. We compared the effects of sufentanil-propofol with fentanyl-propofol anaesthesia in a controlled, randomised, double-blind study of 18 ASA I-II patients aged 23-64 years undergoing major abdominal surgery. Study parameters were haemodynamics (heart rate [HR], arterial [ABP], central venous, and pulmonary arterial pressures, cardiac index [CI]), arterial catecholamine concentrations, and the median frequency of the electroencephalogram (EEG) power spectrum. ⋯ With both regimens, the sympathoadrenal stress response to major abdominal surgery was nearly completely suppressed, resulting in stable haemodynamics during the operations. Sufentanil and fentanyl were equally well suited as analgesic components of total i.v. anaesthesia with propofol.
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During the last five years several authors have reported largely satisfactory results, using the steroid intravenous anaesthetic eltanolone (pregnanolone) for induction of anaesthesia after administering a bolus dose. Until now, however, no investigations have been undertaken, dealing with the infusion pharmacokinetics of eltanolone after arterial blood sampling and using slow induction to quantify the concentration-effect relationship. Secondary objectives were to assess the haemodynamic and respiratory effects. ⋯ The model-dependent pharmacokinetic parameters of eltanolone were characterized by a high total clearance (1.75 +/- 0.22 l min-1), small volumes of distribution (Vc = 7.7 +/- 3.4 l; Vdss = 92 +/- 22 l and relatively short half-lives (t1/2 alpha = 1.5 +/- 0.6 min; t1/2 beta = 27 +/- 5 min; t1/2 gamma = 184 +/- 32 min). (Table 2). The clinical signs revealed a good hypnotic effect, resulting in burst suppression periods in the EEG after 19 min during the first and 15 min during the second infusion cycle. The slow induction enabled a thorough observation of the induction phase. During the first infusion cycle cessation of counting occurred after 7.7 +/- 1.3 min (mean +/- SD), reaction to verbal contact was lost after 10.4 +/- 1.3 min and the corneal reflex was lost only in about one half of the volunteers after 17.9 +/- 2.8. During recovery, the corneal reflex reappeared 9.4 +/- 2.4 min after stop of infusion, first reactions to loud verbal commands were recorded after 24.2 +/- 4.3 min and full orientation was regained after 34.7 +/- 6.2 min. During the second cycle all signs disappeared faster and were regained later. The correlation between clinical signs and corresponding serum concentrations revealed, that in both cycles the disappearance occurred at clearly higher concentrations than the reappearance. The decrease of the systolic arterial pressure showed a maximum of 31% compared to the baseline values, which was statistically significant (P < 0.05). Diastolic arterial blood pressure decreased of about 10%, while heart rate increased significantly of about 24% (P < 0.05). Oxygen saturation remained stable with values between 96 and 100% with the exception of one volunteer. Apnoea was not recorded during the entire observation period. The median value of all pCO2 analyses was 41 mmHg with a range of 25-60 mmHg. The only serious undesirable effect was a seizure during awakening in one volunteer which coincided with polyspike waves in his raw-EEG recordings. (ABSTRACT TR
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[The effect of anesthetic method on enflurane air pollution in non-air conditioned operating rooms].
Pollution of work areas by volatile anaesthetics and nitrous oxide occurs during general anaesthesia. Short anaesthesia procedures are often carried out in operating theatres that are not equipped with air-conditioning systems. Methods of lowering exposure during short procedures, where mask anaesthesia is the usual procedure, are double masks and the laryngeal mask. The aim of our investigation was to determine the possibility of lowering the pollution of the environment to below national and international thresholds in a non-air-conditioned work area and to find out which method of anaesthesia is the most effective in environmental protection, i.e. which has the lowest leakage rate. ⋯ In unventilated work areas, it was not possible to lower the exposure of the personnel by changing the method of anaesthesia. The application of procedures like double or laryngeal masks does not avoid the need for installation of air-conditioning systems in all work areas were anaesthesia is performed.
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Although still rare, pregnancy and delivery in women with spinal cord injuries is becoming more frequent (Table 2). In 85%-90% of patients with lesions above T6 symptoms of autonomic hyperreflexia (Table 1), especially paroxysmal and excessive increases in arterial blood pressure, may occur. In anaesthetising a 31-year-old paraplegic primigravida with a complete transverse spinal lesion at T4 for an elective caesarean section, no indication of hypertonic cardiovascular dysregulation either intra- or postoperatively was observed after repeated epidural administration of bupivacaine. Distinct intraoperative spasticity of the abdominal wall muscles was, however, not influenced by the dosages selected.