The effects of propofol-midazolam-ketamine co-induction on hemodynamic changes and catecholamine response

To compare the clinical efficacy of co-induction with propofol-midazolam-ketamine
with etomidate as the sole induction agent.
Design: Prospective, double-blinded, randomized controlled trial.
Setting: Operating room of a university hospital.
Patients: 60 ASA physical status 1 and 2 patients scheduled for limited elective surgery requiring
general anesthesia.
Interventions: Patients were randomized to two groups to receive etomidate 0.3 mg/kg (single-drug
group) or propofol 0.6 mg/kg + ketamine 0.8 mg/kg + midazolam 0.06 mg/kg (three-drug group).
Measurements: Hemodynamic responses (systolic and diastolic blood pressure, and mean arterial
pressure) were examined at baseline and at one, three, and 5 minutes after tracheal intubation. Plasma
catecholamine levels were measured at baseline, one, and 5 minutes after tracheal intubation.
Main Results: Heart rate (HR) changes differed significantly between the two groups at three minutes
(P = 0.01) and 5minutes (P = 0.00) after tracheal intubation. However, theHR increase in the three-drug group
was in the acceptable range. Percentage changes of epinephrine level differed between the two groups at 5
minutes after tracheal intubation (P = 0.03).
Conclusions: The higher norepinephrine/epinephrine ratio noted in the single-drug group may be implicated in
lower adrenal sympathetic activity. Propofol-midazolam-ketamine co-induction may be used instead of
etomidate for anesthesia induction in patients with hemodynamic instability.