The minimum alveolar concentration of sevoflurane in rats

Abstract

There are only limited data on sevoflurane minimum alveolar concentration (MAC) in rats. This study was designed to determine the minimum alveolar concentration value for sevoflurane in younger and older rats. Minimum alveolar concentration determination was performed in spontaneously breathing animals, 9‐week‐old rats (younger, n=8) and more than 13‐month‐old rats (older, n=8). Rats were instrumented with a silastic catheter in the abdominal aorta via the femoral artery to allow for arterial blood gas sampling. Subsequently, minimum alveolar concentration for sevoflurane was determined in 40 younger and 38 older rats. Minimum alveolar concentration for sevoflurane in younger rats was significantly higher than in the older rats (2.68±0.19 vs. 2.29±0.19, P<0.001). Subgroup analysis indicated that minimum alveolar concentration for sevoflurane was not affected by the presence of an arterial catheter in the abdominal aorta (younger, 2.75±0.08 vs. 2.67±0.21; older, 2.23±0.19 vs. 2.30±0.18). Minimum alveolar concentration is profoundly affected by the age of the animal, but not by limited instrumentation.

Blockade of 5-HT2A and/or 5-HT2C receptors modulates sevoflurane-induced immobility

“…The MAC values we obtained after pretreatment with vehicle control are consistent with those previously determined in Wistar rats of a similar age [19]. Thus, intraperitoneal administration of DMSO apparently did not alter sevoflurane MAC in rats in the present study.…”

Sevoflurane Induces Coherent Slow-Delta Oscillations in Rats

“…In humans, burst suppression occurs at roughly 1.4 times the minimum alveolar concentration (MAC), the dose required to prevent a motor response to a surgical stimulus in half of subjects. Rats in this study exhibited burst suppression at 2.2–2.8% sevoflurane, or roughly 0.9–1.1 MAC ( Kashimoto et al, 2006 ). In addition, sevoflurane-induced alpha dynamics may differ between the two species.…”

Inhaled Anesthetics and Immobility: Mechanisms, Mysteries, and Minimum Alveolar Anesthetic Concentration

“…At an extreme are nonimmobilizer compounds, compounds that have no anesthetic effect, alone or in combination with known anesthetics, despite a lipophilicity that predicts an anesthetizing capacity (5). For example, 1,2-dichlorohexafluorobutane (also called F6 or 2N) has an oil/gas partition coefficient of 44 (5), similar to the value of 47 found for sevoflurane (20), which has a MAC of 2.4% (21,22). However, F6 is not anesthetic at any concentration, including concentrations exceeding 4% (5).…”