Dexmedetomidine reduces propofol and remifentanil requirements during bispectral index-guided closed-loop anesthesia: a double-blind, placebo-controlled trial.
BACKGROUND
The α2-adrenergic agonist dexmedetomidine is a sedative and can be used as an adjunct to anesthetics. Our primary goal was thus to determine the extent to which dexmedetomidine reduces the requirement for propofol and remifentanil.


METHODS
This double-blinded, randomized study (NCT00921284) used an automated dual closed-loop administration to maintain the Bispectral Index between 40 and 60. Sixty-6 ASA physical status I and II patients were given either dexmedetomidine (1 μg/kg over 10 minutes followed by a continuous infusion of 0.5 μg/kg/h throughout surgery) or comparable volumes of saline as a placebo. Propofol and remifentanil requirements were compared using nonparametric tests and expressed as medians (interquartile ranges).


RESULTS
Twenty-eight patients in each group completed the study. Patients given dexmedetomidine required less propofol (1.0 [0.7-1.3] vs 1.3 [1.0-1.7] mg/kg, P = 0.002) and remifentanil (1.2 [1.0-1.4] vs 1.6 [1.1-2.8] μg/kg, P = 0.02) for anesthetic induction. The propofol dosage required for anesthetic maintenance was 29% (with a 95% confidence interval, 18-40) lower in patients given dexmedetomidine (2.2 [1.5-3.0] vs 3.1 [2.4-4.5] mg/kg/h, P = 0.005), whereas the remifentanil dosage was not significantly different (0.16 [0.09-0.17] vs 0.14 [0.13-0.21] μg/kg/h with P = 0.3). The incidence of adverse events, including hemodynamic instability and delayed recovery, was comparable with and without dexmedetomidine. The first postoperative request for morphine analgesia was delayed in patients given dexmedetomidine (median fourth hour vs first hour, P = 0.008).


CONCLUSIONS
Dexmedetomidine administration significantly reduced the requirement for both propofol and remifentanil during anesthetic induction and reduced propofol use during maintenance of anesthesia. Dexmedetomidine also delayed postoperative analgesic use. Dexmedetomidine is a useful adjuvant that reduces anesthetic requirement and provides postoperative analgesia.
From the *Department of Anesthesiology, Hôpital Foch, Suresnes, France; †UVSQ-UFR des Sciences de la Santé Simone Veil, Montigny-le-Bretonneux, France; ‡Outcomes Research Consortium, Cleveland, Ohio; §Department of Anesthesiology and Intensive Care, Hôpital Tenon, Paris, France; ‖Pharmacy, Hôpital Foch, Suresnes, France; ¶Department of Anesthesiology, Leeds General Infirmary, Leeds, United Kingdom; #UPMC, Paris, France; and **Department of Outcomes Research, Cleveland Clinic, Cleveland, Ohio.
Morgan
M
Le Guen
Ngai
N
Liu
Felix
F
Tounou
Marion
M
Augé
Olivier
O
Tuil
Thierry
T
Chazot
Dominique
D
Dardelle
Pierre-Antoine
PA
Laloë
Francis
F
Bonnet
Daniel I
DI
Sessler
Marc
M
Fischler
D000328:Adult; D000368:Aged; D000465:Algorithms; D000762:Anesthesia Recovery Period; D000768:Anesthesia, General / Q000379:methods*; D000771:Anesthesia, Intravenous / Q000379:methods*; D018686:Anesthetics, Intravenous / Q000008:administration & dosage*; D001279:Atracurium; D056805:Consciousness Monitors; D020927:Dexmedetomidine / Q000494:pharmacology*; D004311:Double-Blind Method; D004809:Ephedrine / Q000627:therapeutic use; D005260:Female; D006439:Hemodynamics / Q000187:drug effects / Q000502:physiology; D006801:Humans; D006993:Hypnotics and Sedatives / Q000494:pharmacology*; D007432:Intraoperative Period; D008297:Male; D008875:Middle Aged; D003473:Neuromuscular Nondepolarizing Agents; D010880:Piperidines / Q000008:administration & dosage*; D015742:Propofol / Q000008:administration & dosage*; D000077208:Remifentanil; D014662:Vasoconstrictor Agents / Q000627:therapeutic use
D018686:Anesthetics, Intravenous; D006993:Hypnotics and Sedatives; D003473:Neuromuscular Nondepolarizing Agents; D010880:Piperidines; D014662:Vasoconstrictor Agents; D001279:Atracurium; D020927:Dexmedetomidine; D004809:Ephedrine; D000077208:Remifentanil; D015742:Propofol