title: Haemodynamic changes and heart rate variability during midazolam-propofol co-induction.
abstract: In a prospective, blind, randomised study, we examined the effects of midazolam-propofol co-induction on haemodynamic (blood pressure, heart rate and stroke volume) and heart rate variability. The latter was measured by spectral analysis using the maximum-entropy method to calculate the following: the low frequency component (LF), which reflects both the cardiac sympathetic and parasympathetic activity, the high frequency component (HF) and entropy, which reflects the cardiac parasympathetic activity, the total power (TP), calculated by the addition of LF and HF, and the LF/HF ratio, which reflects the balance between the cardiac sympathetic and parasympathetic nervous activity. Forty patients were randomly allocated to the propofol group and the midazolam-propofol group, and the parameters described above were calculated at baseline (T1), post induction (T2), after tracheal intubation (T3), and 3 min (T4) and 5 min after intubation (T5). Propofol was administered at 2.5 mg.kg(-1) in the propofol group and midazolam at 0.1 mg.kg(-1) followed by propofol at 1.5 mg.kg(-1) in the midazolam-propofol group for anaesthesia induction. Then, propofol was administered at 4-6 mg.kg(-1)propofol for maintenance in both groups. The midazolam-propofol group showed compensated haemodynamic changes, which were related to significant increases in the LF/HF ratio at T2, T4 and T5 (p = 0.011, 0.038 and 0.034). These results suggest that the midazolam-propofol combination yielded compensated modulatory effects on the cardiovascular system, including preserved baroreflex activity.
authors.affiliation: Section of Anaesthesiology and Clinical Physiology, Department of Oral Restitution, Division of Oral Health Sciences, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Ni Ni
authors.initials: NN
authors.lastname: Win
authors.forename: H
authors.initials: H
authors.lastname: Kohase
authors.forename: F
authors.initials: F
authors.lastname: Yoshikawa
authors.forename: R
authors.initials: R
authors.lastname: Wakita
authors.forename: M
authors.initials: M
authors.lastname: Takahashi
authors.forename: N
authors.initials: N
authors.lastname: Kondo
authors.forename: D
authors.initials: D
authors.lastname: Ushito
authors.forename: M
authors.initials: M
authors.lastname: Umino
mesh_terms: D000328:Adult; D018686:Anesthetics, Intravenous / Q000494:pharmacology; D017704:Baroreflex / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D004311:Double-Blind Method; D004562:Electrocardiography / Q000187:drug effects; D005260:Female; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D006993:Hypnotics and Sedatives / Q000494:pharmacology; D007442:Intubation, Intratracheal; D008297:Male; D008874:Midazolam / Q000494:pharmacology*; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods; D015742:Propofol / Q000494:pharmacology*; D011446:Prospective Studies; D013318:Stroke Volume / Q000187:drug effects*
chemical_list: D018686:Anesthetics, Intravenous; D006993:Hypnotics and Sedatives; D008874:Midazolam; D015742:Propofol