Der Anaesthesist
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Randomized Controlled Trial Clinical Trial
[Propofol and etomidate-Lipuro for induction of general anesthesia. Hemodynamics, vascular compatibility, subjective findings and postoperative nausea].
Etomidate has become an important induction agent in high-risk patients because of its cardiovascular stability. Its unwanted side-effects such as pain on injection and thrombophlebitis could be significantly reduced by a new (medium chain triglyceride and soya bean) emulsion formulation. Propofol is solved in a mixture of long chain triglyceride and soya bean emulsion. In this double-blind, randomized study we compared the haemodynamic effects, the patients' sensations, signs of thrombophlebitis and postoperative nausea and vomiting (PONV) following injection of both drugs. ⋯ Etomidate formulated in a medium chain lipid emulsion causes significant less discomfort for the patients than propofol, which is solved in a long chain formulation. Myocloni, however, occur significantly more frequently after etomidate than after propofol.
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Randomized Controlled Trial Clinical Trial
[The effect of nitroglycerin on cerebrovascular circulation, cerebrovascular CO2-reactivity and blood flow rate in basal cerebral arteries].
The cerebral haemodynamic effects of vasodilators are of clinical interest because a decrease in mean arterial pressure (MAP) might alter global cerebral blood flow (CBF). Luxury perfusion of the brain, contrast, might be unfavourable in patients with reduced intracranial compliance. Despite the widespread use of nitroglycerine (NTG), little is known about the cerebral haemodynamic consequence of NTG infusions in humans. This prospective, controlled study was designed: (1) to investigate the effects of NTG on CBF and cerebrovascular CO2 reactivity and (2) to compare reference measurements of global CBF with transcranial Doppler monitoring (TCD) of middle cerebral artery flow velocity (VMCA). ⋯ This study demonstrates that during fentanyl/midazolam anaesthesia NTG may cause a major increase in CBF as long as CPP does not decrease considerably. Our results further suggest that NTG causes vasodilation of basal cerebral arteries, inducing a discrepancy between relative changes in CBF and VMCA. Consequently, TCD measurements during infusion of NTG should not be directly compared with preceding measurements of MCA flow velocity.
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Randomized Controlled Trial Clinical Trial
[Variation in inspiratory gas flow in pressure support ventilation. The effect on respiratory mechanics and respiratory work].
During pressure support ventilation (PSV), the timing of the breathing cycle is mainly controlled by the patient. Therefore, the delivered flow pattern during PSV might be better synchronised with the patient's demands than during volume-assisted ventilation. In several modern ventilators, inspiration is terminated when the inspiratory flow decreases to 25% of the initial peak value. However, this timing algorithm might cause premature inspiration termination if the initial peak flow is high. This could result not only in an increased risk of dyssynchronization between the patient and the ventilator, but also in reduced ventilatory support. On the other hand, a decreased peak flow might inappropriately increase the patient's inspiratory effort. The aim of our study was to evaluate the influence of the variation of the initial peak-flow rate during PSV on respiratory pattern and mechanical work of breathing. ⋯ COPD patients had significantly higher pressure support than control patients. With decreasing inspiratory flow, Wpi increased significantly in COPD patients.(ABSTRACT TRUNCATED)
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Randomized Controlled Trial Comparative Study Clinical Trial
[The effect of the laryngeal mask airway on the postoperative incidence of vomiting and sore throat in children].
100 ASA I and II children, aged 4 to 14 years, and scheduled for strabismus surgery, were randomly assigned to one of the following groups: group 1 (n = 50): endotracheal tube, group 2 (n = 50): laryngeal mask airway. Apart from airway management, the anaesthesiological procedures were identical in both groups: induction with 2-3 mg/kg propofol, 0.02 mg/kg alfentanil, 0.05 mg/kg vecuronium, and 0.01 mg/kg atropine. After endotracheal intubation or insertion of the laryngeal mask, anaesthesia was continued with 6-15 mg/kg.h propofol and 10-30 micrograms/kg.h alfentanil. All patients were ventilated with N2O/O2 (2:1). No antiemetics were given, gastric contents were not aspirated. Postoperative nausea and vomiting (PONV) were recorded by 24 h, the incidence of sore throats was recorded 8, 12, and 24 h post-operatively. ⋯ In children undergoing strabismus surgery, the laryngeal mask airway was superior to the endotracheal tube in terms of PONV and was associated with fewer local complications such as sore throat.
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Randomized Controlled Trial Clinical Trial
[The effects of cimetidine on the pharmacodynamics of rocuronium].
Cimetidine is a commonly used H2-receptor antagonist that has been recommended for the prevention of acid aspiration syndrome and has been shown to potentiate vecuronium-induced neuromuscular block. The present study was designed to investigate the influence of a single IV dose of cimetidine on the neuromuscular effects of rocuronium, an analogue of vecuronium with a short onset time. ⋯ The results of the present study demonstrate that cimetidine does not increase the duration of rocuronium neuromuscular blockade. Inhibition of the cytochrome P450 system or a direct effect at the neuromuscular junction have been suggested as the mechanisms of drug interaction associated with cimetidine. Impairment of hepatic microsomal drug metabolism results in a prolonged duration of action of vecuronium, which appears to be eliminated primarily via the liver. Data on the elimination pathway of rocuronium in humans are not available. The fact that cimetidine does not alter the recovery from rocuronium-induced neuromuscular block confirms a previous suggestion that rocuronium may not be eliminated principally by the liver. A direct effect of cimetidine on the neuromuscular junction could not be confirmed by this study. Therefore, cimetidine can be given as premedication without a risk of prolonged rocuronium block.