Dexmedetomidine suppresses the decrease in blood pressure during anesthetic induction and blunts the cardiovascular response to tracheal intubation

Study Objective: To evaluate the effect of dexmedetomidine combined with fentanyl on hemodynamics. Design: Prospective, double-blinded, randomized study. Setting: Operating room of a university hospital. Patients: 30 ASA physical status II and III patients with mild-to-moderate cardiovascular disease. Interventions: Patients were assigned to one of three groups: Group D-F2 [dexmedetomidine, effect-site concentration (ESC) of fentanyl = two ng/mL]; Group F2 (placebo, ESC of fentanyl = two ng/mL), or Group F4 (placebo, ESC of fentanyl = 4 ng/mL). Measurements: Dexmedetomidine (an initial dose of 1.0 mu g/kg for 10 min, followed by a continuous infusion of 0.7 mu g-kg(-1.)hr(-1)) or placebo saline was administered 15 minutes before anesthetic induction. Anesthesia was induced with propofal and fentanyl using a target-controlled infusion system. Hemodynamic parameters: systolic (SBP) and diastolic blood pressures (DBP), and heart rate (HR) during anesthetic induction were measured and the percent changes were calculated for both induction and intubation. Main Results: After inducing anesthesia, SBP was significantly higher in Group D-F2 (127 24 mmHg) than Group F2 (90 +/- 20 mmHg) or Group F4 (77 +/- 21 mmHg). The SBP in Groups F2 and F4 reached 160 +/- 31 mmHg and 123 +/- 36 mmHg, respectively, after intubation, but no significant change in SBP was noted in Group D-F2. The percent increase in SBP due to tracheal intubation in Group D-F2 was 3% +/- 4% and was significantly lower than that of Group F2 (70% +/- 34%) or Group F4 (45% +/- 36%). Conclusion: Dexmedetomidine combined with fentanyl during anesthetic induction suppresses the decrease in blood pressure due to anesthetic induction and also blunts the cardiovascular response to tracheal intubation. (C) 2009 Elsevier Inc. All rights reserved.