Myocardial recovery from the cardiac depressant effects of enflurane and halothane.
Recovery from the cardiac depressant effects of enflurane and halothane was examined in the dog heart-lung preparation (HLP) and in right ventricular muscle isolated from guinea pig hearts. In the HLP. recovery was studied under two conditions: (1) After a two-hour exposure to anesthetic concentrations increasing from 0.36 to 1.2 MAC, and (2) after a one-hour exposure to a single concentration that raised the left atrial pressure (LAP) to 9 to 10 mmHg. Under either condition, +dP/dtmax. was significantly less depressed with enflurane and returned to preanesthetic control levels, while recovery with halothane remained significantly below control. Following the longer exposure. recovery of the LAP and left ventricular function curves (LVFC) was significantly less with halothane; however, this difference was not observed after the shorter exposure period. In electrically paced, isometrically contracting right ventricular strips exposed for one hour to 2.25 vol% enflurane (a concentration that reduced contractility by 45%), force development returned within 60 minutes to values above preanesthetic control values. After an identical depression for one hour with halothane (0.80 vol%), force development recovered to values less than those observed following enflurane. These data indicate that the recovery from anesthetic-induced negative inotropic effects in isolated cardiac preparations is better with enflurane than halothane.
Seifen
A B
AB
Departments of Pharmacology and Interdisciplinary Toxicology and Anesthesiology, University of Arkansas for Medical Sciences, Little Rock AR 72205, USA.
Seifen
E
E
Kennedy
R H
RH
Bray
J P
JP
Bushman
G A
GA
Loss
G E
GE
D018685:Anesthetics, Inhalation / Q000633:toxicity*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D003864:Depression, Chemical; D004285:Dogs; D004737:Enflurane / Q000633:toxicity*; D005260:Female; D006168:Guinea Pigs; D006221:Halothane / Q000633:toxicity*; D006321:Heart / Q000187:drug effects* / Q000502:physiology; D066298:In Vitro Techniques; D008297:Male; D016277:Ventricular Function, Left / Q000187:drug effects
D018685:Anesthetics, Inhalation; D004737:Enflurane; D006221:Halothane