Hemodynamic effects of an intravenous infusion of medetomidine at six different dose regimens in isoflurane-anesthetized dogs.
This study investigated the dose dependency of the hemodynamic effects of IV medetomidine (MED) constant-rate infusion (CRI) during isoflurane anesthesia. Twenty-four healthy beagles randomly received one of six MED CRI regimens. A loading dose of MED was administered IV at 0.2, 0.5, 1.0, 1.7, 4.0, or 12.0 ug/kg-1 for 10 minutes, followed by a maintenance CRI providing identical dose amounts over 60 minutes. Heart rate and mean arterial blood pressure were recorded, blood gases were analyzed, and cardiac index (CI) was determined. Statistical analysis involved a repeated measures linear model. Baseline CI demonstrated a dose-dependent decrease as the MED dose increased, with decreases of 14.9% (SD, 12.7%), 21.7% (17.9%), 27.1% (13.2%), 44.2% (9.7%), 47.9% (8.1%), and 61.2% (14.1%) at doses of 0.2, 0.5, 1.0, 1.7, 4.0, and 12.0 ug/kg-1, respectively. The four lowest doses induced limited and transient changes in heart rate, mean arterial pressure, and CI. Further investigation into potential perioperative uses of MED CRI is warranted.
Faculty of Veterinary Medicine, Université de Montréal, Groupe de Recherche en Pharmacologie Animaledu Québec, Department of Veterinary Biomedicine, 1500 rue des Vétérinaires, Saint-Hyacinthe, QC, Canada.
Johanna
J
Kaartinen
Daniel
D
Pang
Maxim
M
Moreau
Outi
O
Vainio
Francis
F
Beaudry
Jerome
J
del Castillo
Leigh
L
Lamont
Sophie
S
Cuvelliez
Eric
E
Troncy
D058647:Adrenergic alpha-2 Receptor Agonists / Q000008:administration & dosage / Q000494:pharmacology*; D018685:Anesthetics, Inhalation; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D004285:Dogs / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D007262:Infusions, Intravenous / Q000662:veterinary; D007530:Isoflurane; D008297:Male; D020926:Medetomidine / Q000008:administration & dosage / Q000494:pharmacology*
D058647:Adrenergic alpha-2 Receptor Agonists; D018685:Anesthetics, Inhalation; D007530:Isoflurane; D020926:Medetomidine