title: [Causative factors of esmolol-induced reduction in arterial blood pressure differ in accordance with its doses].
abstract: BACKGROUND
  Because the causative factors responsible for hypotension by esmolol remain to be fully elucidated, this study investigated whether different doses of esmolol may be different in causing esmolol-induced hypotension in dogs anaesthetized with sevoflurane.
  
  
  METHODS
  The ES 25, ES 100 and ES 400 groups (n = 8, each) randomly received esmolol that was infused at a constant rate at 25, 100, or 400 microg x kg(-1) x min(-1) during a 60 min-infusion period, respectively.
  
  
  RESULTS
  Esmolol produced dose-dependent decreases in mean arterial pressure (MAP) which were not associated with any changes in heart rate. With the ES 25 group, the hypotensive effect was caused by significant reductions in systemic vascular resistance (SVR) without any changes in cardiac index (CI). In contrast, the hypotensive effect in the ES 400 group was due to the significant decrease in CI resulting from significant reductions in cardiac contractility without any changes in SVR. Hypotension in the ES 100 group resulted in the significant reductions in both SVR and cardiac contractility.
  
  
  CONCLUSIONS
  These findings suggest that a low dose of esmolol might induce the vasodilating effect resulting in changes in the resistance of vessels and thus may provide a cardiac safety during perioperative periods.
authors.affiliation: Department of Dental Anesthesiology, Showa University Dental Hospital, Tokyo 145-8515.
authors.forename: Kou
authors.initials: K
authors.lastname: Fujiwara
authors.forename: Rikuo
authors.initials: R
authors.lastname: Miasuda
authors.forename: Shohei
authors.initials: S
authors.lastname: Takeda
mesh_terms: D058671:Adrenergic beta-1 Receptor Antagonists / Q000008:administration & dosage* / Q000494:pharmacology; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D004285:Dogs; D011412:Propanolamines / Q000008:administration & dosage* / Q000494:pharmacology; D011897:Random Allocation
chemical_list: D058671:Adrenergic beta-1 Receptor Antagonists; D011412:Propanolamines; C036604:esmolol