Minimum alveolar concentration of halogenated volatile anaesthetics in left ventricular hypertrophy and congestive heart failure in rats.
BACKGROUND
Although many physiological and pathological conditions affect minimal alveolar concentration (MAC), there are no reliable data on the MAC for halogenated anaesthetics during left ventricular hypertrophy (LVH) and congestive heart failure (CHF). The aim of this experimental study was to determine the MAC values of halothane, isoflurane, and sevoflurane in rats, at early and later stages of cardiomyopathic hypertrophy.


METHODS
LVH was induced by ascending aortic stenosis in 3-4-week-old rats. LVH and CHF in each animal were assessed weekly by echocardiography. MAC of halothane, isoflurane, and sevoflurane was determined using the tail-clamp technique in spontaneously breathing rats from each group. Response vs no-response data were analysed using logistic regression analysis. Data are medians (95% confidence interval).


RESULTS
The MAC of halothane [1.30% (1.26-1.34)], isoflurane [1.52% (1.48-1.57)], and sevoflurane [2.93% (2.78-3.07)] in rats with LVH was not different from sham-operated rats [respectively, 1.23% (1.20-1.26), 1.52% (1.47-1.56), and 2.90% (2.79-3.00)]. Conversely, the MAC of halothane [1.44 (1.39-1.50)] and isoflurane [1.74 (1.69-1.78)], but not sevoflurane [2.99 (2.93-3.06)], was significantly increased in rats with CHF.


CONCLUSIONS
MAC values for halothane, isoflurane, and sevoflurane were unchanged in rats with pressure-induced overload LVH. Conversely, the MAC for halothane and isoflurane, but not sevoflurane, was significantly increased in rats with CHF.
Barbry
T
T
Laboratoire d'Anesthésiologie (EA 3975), Département d'Anesthésie-Réanimation, Centre Hospitalier Universitaire Pitié-Salpêtrière, 47-83 Boulevard de l'Hôpital, 75651 Paris Cedex 13, France.
Le Guen
M
M
De Castro
V
V
Coriat
P
P
Riou
B
B
Vivien
B
B
D018685:Anesthetics, Inhalation / Q000493:pharmacokinetics*; D000818:Animals; D018450:Disease Progression; D004305:Dose-Response Relationship, Drug; D006221:Halothane / Q000493:pharmacokinetics; D006333:Heart Failure / Q000378:metabolism*; D017379:Hypertrophy, Left Ventricular / Q000378:metabolism*; D007530:Isoflurane / Q000493:pharmacokinetics; D008297:Male; D008738:Methyl Ethers / Q000493:pharmacokinetics; D011650:Pulmonary Alveoli / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D000077149:Sevoflurane
D018685:Anesthetics, Inhalation; D008738:Methyl Ethers; D000077149:Sevoflurane; D007530:Isoflurane; D006221:Halothane