title: Cardiovascular depression by isoflurane and concomitant thoracic epidural anesthesia is reversed by dopamine.
abstract: Interactive effects between exogenous dopamine (DA) and isoflurane (I) combined with thoracic epidural blockade (TEA) were studied in dogs during chloralose anesthesia. The I-TEA intervention per se decreased heart rate (HR; 28%), mean arterial pressure (MAP; 63%), cardiac output (CO; 54%), left ventricular dP/dt (LVdP/dt; 75%) and LVdP/dt/systolic arterial pressure (SAP; 42%). Prior to the I-TEA intervention, dopamine increased MAP, CO, LVdP/dt, LVdP/dt/SAP and stroke volume (SV) already at the dose 10 micrograms.kg-1.min-1 and, additionally, increased mean pulmonary artery pressure (MPAP) at the dose 20 micrograms.kg-1.min-1. During the I-TEA intervention, the DA-induced increases in MAP and systemic vascular resistance (SVR) were significantly higher than prior to I-TEA, as indicated by significant ANOVA interactive effects. At the dose 10 micrograms.kg-1.min-1, DA restored MAP, CO, LVdP/dt, LVdP/dt/SAP and SV to levels found before the I-TEA intervention, while HR was restored first at the dose 20 micrograms.kg-1.min-1. At the dose 20 micrograms.kg-1.min-1, DA also increased MAP (39%), LVdP/dt (119%), LVdP/dt/SAP (73%), SVR (28%) and MPAP (70%) above levels prior to I-TEA. To conclude, exogenous dopamine effectively and dose-dependently counters cardiovascular depression induced by the anesthetic technique of combining I and TEA. The pressor and systemic vasoconstrictor actions of dopamine are potentiated by conjoint administration of I and TEA.
authors.affiliation: Department of Anesthesiology, Ostra Hospital, University of Gothenburg, Sweden.
authors.forename: C
authors.initials: C
authors.lastname: Raner
authors.forename: B
authors.initials: B
authors.lastname: Biber
authors.forename: J
authors.initials: J
authors.lastname: Lundberg
authors.forename: J
authors.initials: J
authors.lastname: Martner
authors.forename: O
authors.initials: O
authors.lastname: Winsö
mesh_terms: D000767:Anesthesia, Epidural; D000769:Anesthesia, Inhalation; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D004285:Dogs; D004298:Dopamine / Q000097:blood / Q000494:pharmacology*; D005260:Female; D006321:Heart / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D007530:Isoflurane / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D008297:Male; D008619:Mepivacaine / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D009200:Myocardial Contraction / Q000187:drug effects; D009638:Norepinephrine / Q000097:blood; D010101:Oxygen Consumption / Q000187:drug effects; D013904:Thoracic Vertebrae; D014655:Vascular Resistance / Q000187:drug effects; D017725:Ventricular Pressure / Q000187:drug effects
chemical_list: D008619:Mepivacaine; D007530:Isoflurane; D004298:Dopamine; D009638:Norepinephrine