Xenon alters right ventricular function
ABSTRACT In contrast to other volatile anesthetics, xenon produces less cardiovascular depression with fewer fluctuations of various hemodynamic parameters, but reduces cardiac output (CO) in vivo. Besides an increase in left ventricular afterload and reduction of heart rate, an impairment of the right ventricular function might be an additional pathophysiological mechanism for the reduction of CO. Therefore, we used an animal model to study the effects of xenon as a supplemental anesthetic on right ventricular function, especially right ventricular afterload.
Right ventricular function was monitored with a volumetric pulmonary artery catheter in 11 pigs during general anesthesia with thiopental. Six animals received additional 70% (volume) xenon (equivalent to 0.55 MAC minimum alveolar concentration). Parameters for systolic function, afterload, and preload were calculated at baseline and during 50 min of xenon application, and in a corresponding control group. Significant differences were detected by multivariate analyses of variance for repeated measures.
Xenon reduced CO on average by 30% and increased pulmonary arterial elastance by 60%, which led to a reduction of the right ventricular ejection fraction by 25%. Whereas right ventricular preload remained stable, maximal slope of pulmonary artery pressure and the right ventricular elastance increased. No effect on the ratio of stroke work and end-diastolic volume was found.
The reduction in CO during xenon anesthesia was partly due to an impairment of the right ventricular function, mainly caused by an increased afterload, without an impairment of systolic ventricular function.
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ABSTRACT: Jan-Hinrich BaumertDept of Anaesthesiology, UMC St Radboud, Nijmegen, NetherlandsAbstract: Xenon has been in use as an anesthetic for more than 50 years. Although it exhibits some of the properties of an ideal anesthetic, the technical complexity of xenon equipment and the high cost of the gas have prevented widespread use of xenon anesthesia. The main beneficial features of xenon anesthesia are fast induction and emergence because of low solubility in blood and tissues, along with remarkably stable hemodynamics even in patients with impaired cardiac function. Xenon has proven to be a safe and well-tolerated anesthetic in clinical trials. The primary mechanism by which xenon produces anesthesia – antagonism at the neuronal N-methyl-D-aspartate receptor – and the absence of vasodilating effects distinguish xenon from most other inhaled and intravenous anesthetics. In addition, xenon can protect cells from ischemia-reperfusion damage. This effect was demonstrated in myocardium and neuronal cells as well. Myocardial and cerebral infarction sizes after ischemia can be reduced substantially by xenon, even when administered after the initial insult. Because of its high cost, routine xenon anesthesia may be justified only if it is associated with fewer perioperative complications, shorter duration of hospital stay or significant reduction of perioperative risk. Clinical studies to identify a specific group of patients in which these requirements are met are still lacking.Keywords: xenon, anesthesiaOpen Access Surgery 01/2009; DOI:10.2147/OAS.S4592
Article: Update on inhalational anaesthetics[Show abstract] [Hide abstract]
ABSTRACT: Inhalational anaesthetic agents are a cornerstone in modern anaesthetic practice. The currently used compounds are very effective and have a good safety profile. In addition, it has been demonstrated that they possess organ-protective properties that might provide an additional tool in the treatment or prevention of the consequences of organ ischaemia-reperfusion injury or both. The present review summarizes some of the most recent findings on this subject. The mechanisms underlying the organ-protective effects of inhalational anaesthetics continue to be further unravelled. The main challenge, however, is to determine the clinical importance of these protective effects and their potential benefits for patients. Initial observations in cardiac surgery are encouraging, and the first clinical studies on other organ systems are being published. Noble gases share these organ-protective properties and may provide an additional tool for this purpose both in situations in which anaesthesia is needed (xenon) or in cases in which anaesthesia is not necessary (helium). In the experimental setting, inhalational anaesthetics have protective effects against ischaemia-reperfusion injury. Initial perioperative data suggest that these effects may also result into clinically relevant improved organ function. However, further research will be needed to reveal whether these organ-protective properties will ultimately translate into an improved short-term and long-term postoperative outcome.Current opinion in anaesthesiology 05/2009; 22(4):491-5. DOI:10.1097/ACO.0b013e32832bca38 · 2.53 Impact Factor
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ABSTRACT: Xenon is a new inhaled anaesthetic agent featured by a rapid onset and reversibility and by the lack of significant haemodynamic effect. The high value of the minimal alveolar concentration precludes the concomitant use of high inspired oxygen concentrations and makes it more an adjuvant than a main anaesthetic agent. Neuroprotective effects remains to be definitely documented. The use of Xenon introduces a significant cost in excess that challenges its availability in an anaesthetic department.Le Praticien en Anesthésie Réanimation 09/2009; 13(4). DOI:10.1016/j.pratan.2009.07.011