Systemic and Regional Hemodynamics of Isoflurane and Sevoflurane in Rats

Abstract

The authors studied the effects of sevoflurane and isoflurane on systemic hemodynamics and regional blood flow distribution (microsphere technique) in 15 rats during general anesthesia with intravenous chloralose and controlled ventilation. Inhaled anesthetics were applied to reduce mean arterial blood pressure (MAP) to 70 mm Hg (1.66 vol% sevoflurane and 0.96 vol% isoflurane) and 50 mm Hg (MAP 50; 3.95 vol% sevoflurane and 2.43 vol% isoflurane). Control recordings were obtained with intravenous chloralose only. At a MAP of 70 mm Hg, both anesthetics reduced heart rate, cardiac output, and systemic vascular resistance to a similar degree. Isoflurane decreased systemic vascular resistance markedly at a MAP of 50 mm Hg and thereby maintained cardiac output at higher levels than sevoflurane. The left ventricular rate-pressure product decreased comparably with both anesthetics. Cerebral blood flow increased dose-dependently with both inhaled anesthetics but to a greater degree with isoflurane. Total hepatic blood flow remained unchanged from control at a MAP of 70 mm Hg but decreased at a MAP of 50 mm Hg. This was due to reductions of hepatic arterial and portal venous tributaries. Renal blood flow was reduced with only the high concentrations of the anesthetics. Myocardial blood flow was reduced at all concentrations of volatile anesthetic; however, the decrease was less with isoflurane. This would indicate a more pronounced coronary vasodilation by isoflurane as the rate-pressure product, as a measure of the actual left ventricular oxygen demand, decreased by comparable degrees with both anesthetics. Our results indicate that sevoflurane and isoflurane (each approximately 0.7 MAC) have no dissimilar systemic and regional hemodynamic effects at a MAP of 70 mm Hg in this animal model. At higher concentrations (approximately 1.7 MAC), cerebral blood flow was more with isoflurane than with sevoflurane and was associated with a more pronounced vasodilation in the myocardium.

Nephrotoxicity of Halogenated Inhalational Anaesthetics: Fictions and Facts

“…1). Thus, regulation of perfusion did not differ from the awake physiologic state and the obvious conclusion from these experiments was that there was no genuine negative effect on blood flow [5].…”

Sevoflurane ameliorates doxorubicin-induced myocardial injury by affecting the phosphorylation states of proteins in PI3K/Akt/mTOR signaling pathway

“…Therefore, 2-µM DOX was added to cell culture in the present study. Conzen et al [16] reported that 2.4% sevoflurane showed obvious therapeutic results in a rat model and thus the same concentration was used here. LY294002 and 3-MA was also administered based on previous literature [17].…”

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“…Within the sequelae of events, proinflammatory mediators such as TNF-α and IL-1β are key players, causing the microvascular dysfunction and perfusion failure. 8 Many imaging techniques have been previously used to study the hepatic microcirculation, such as use of gamma-emitting radionuclide-labeled microspheres, 4,5 laser Doppler flowmetry, 6 and computed tomography. 7 However, CEUS has still not been reported in the monitoring of liver microcirculation after ischemia-reperfusion injury, although it is a real-time and radiation-free method versus the other techniques.…”

“…1,2 Regarding the liver, hepatic ischemia-reperfusion injury is commonly a consequence of prolonged portal triad clamping followed by reperfusion during surgical resection, performed as an elective preplanned procedure or as an emergency maneuver, to control excessive bleeding from the cut hepatic surface. 2,3 Many techniques have been previously used for the study of hepatic microcirculation, such as the use of gamma-emitting radionuclide-labeled microspheres, 4,5 laser Doppler flowmetry, 6 and computed tomography. 7 However, as a method in monitoring microcirculation in many other organs and tissues, contrast-enhanced ultrasonography (CEUS) has not still been mentioned in this area.…”