当前位置： SCI文献检索 > ANESTHESIOLOGY期刊下所有文献 > Effects of isoflurane on ouabain toxicity in canine Purkinje fibers. Comparison with halothane.

Effects of isoflurane on ouabain toxicity in canine Purkinje fibers. Comparison with halothane.

Abstract：

BACKGROUND:Although halothane reduces digitalis toxicity, other anesthetics, notably cyclopropane, increase toxicity. This study determined the effects of isoflurane on digitalis toxicity in isolated cardiac tissue and compared these effects with those of halothane. METHODS:Standard microelectrode techniques were used to record action potentials from excised canine Purkinje fibers. Fibers were paced at cycle lengths between 1,000 and 250 ms for 20 beats to induce delayed afterdepolarizations, which are membrane potential oscillations indicative of intracellular Na+ and Ca2+ overload, produced in these experiments by digitalis toxicity. The digitalis glycoside ouabain, 2 x 10(-7) M, was added to the Tyrode's solution superfusate to induce delayed after-depolarizations. Action potential variables and the coupling interval and amplitude of afterdepolarizations were then measured. Isoflurane (0.5%, 1%, or 2%) was added with a calibrated vaporizer (n = 8). In a second set of experiments (n = 10), isoflurane 1.25% or halothane 0.75% was added to the superfusate. After measurements had been made, the other agent was substituted. RESULTS:Ouabain produced primary and secondary delayed afterdepolarizations, which were reduced in amplitude by isoflurane in a dose-related manner (P = 0.0002). Action potential duration to 90% repolarization was shortened by ouabain (P = 0.009) and remained shortened during isoflurane administration. Action potential duration to 50% repolarization was shortened by isoflurane 2%. Halothane and isoflurane were equally effective in reducing the amplitude of delayed afterdepolarizations (both P = 0.0002). In three fibers, triggered extrasystoles appeared. Halothane and isoflurane each abolished extrasystoles. In two fibers, sustained triggered activity appeared. Isoflurane abolished the arrhythmia in each fiber. CONCLUSIONS:Isoflurane and halothane are equally effective in reducing delayed afterdepolarizations induced by ouabain toxicity.

journal_name

Anesthesiology

journal_title

Anesthesiology

authors

Gallagher JD

doi

10.1097/00000542-199412000-00026

subject

Has Abstract

pub_date

1994-12-01 00:00:00

pages

1500-10

issue

eissn

0003-3022

issn

1528-1175

journal_volume

pub_type

杂志文章

在线工具

Effects of isoflurane on ouabain toxicity in canine Purkinje fibers. Comparison with halothane.