The effect of intravenously administered dexmedetomidine on perioperative hemodynamics and isoflurane requirements in patients undergoing abdominal hysterectomy.
The effects of two doses of dexmedetomidine (0.3 or 0.6 micrograms.kg-1), fentanyl 2.0 micrograms.kg-1, or saline as a single intravenous bolus administered 10 min prior to the induction of anesthesia were assessed in double-blind, randomized study in 96 women undergoing abdominal hysterectomy. In each patient, anesthesia was induced with thiopental 4.0 mg.kg-1, and after the effect of succinylcholine had dissipated, isoflurane 0.3% end-tidal concentration in 70% nitrous oxide was begun to maintain anesthesia. The isoflurane concentration was adjusted to maintain blood pressure and heart rate within 20% of preoperative values, and fentanyl was given if the end-tidal isoflurane concentration exceeded 1.5%. In all groups, blood pressure and heart rate increased after tracheal intubation. However, the increase in blood pressure and heart rate was significantly less in the higher dexmedetomidine (0.6 micrograms.kg-1) group than in the saline group (P less than 0.01). Also, the postintubation increase in heart rate was significantly less (P less than 0.05) in the dexmedetomidine 0.6 micrograms.kg-1 group (increase of 18 +/- 3 beats per min) compared to the fentanyl group (increase of 26 +/- 3 beats per min). In patients receiving dexmedetomidine 0.3 micrograms.kg-1, the increase in blood pressure or heart rate did not differ from that of the saline group. The mean end-tidal isoflurane concentration was significantly less in the women receiving the higher dose of dexmedetomidine (0.35%) than in those receiving saline (0.47%) or fentanyl (0.48%), although the reduction was not clinically important.(ABSTRACT TRUNCATED AT 250 WORDS)
Department of Anesthesia, Women's Hospital, Helsinki University Central Hospital, Finland.
M
M
Aho
A M
AM
Lehtinen
O
O
Erkola
A
A
Kallio
K
K
Korttila
D000316:Adrenergic alpha-Agonists / Q000008:administration & dosage; D000328:Adult; D000769:Anesthesia, Inhalation; D004311:Double-Blind Method; D005260:Female; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage*; D007044:Hysterectomy; D007093:Imidazoles / Q000008:administration & dosage*; D007275:Injections, Intravenous; D007530:Isoflurane; D020926:Medetomidine; D008875:Middle Aged; D011229:Preanesthetic Medication
D000316:Adrenergic alpha-Agonists; D006993:Hypnotics and Sedatives; D007093:Imidazoles; D007530:Isoflurane; D020926:Medetomidine