Presented in part at the International Anaesthesia Research Society 80th Clinical and Scientific Congress on March 2006 in San Francisco, California.
Haemodynamic changes and heart rate variability during midazolam-propofol co-induction*
Version of Record online: 14 MAY 2007
Volume 62, Issue 6, pages 561–568, June 2007
How to Cite
Win, N. N., Kohase, H., Yoshikawa, F., Wakita, R., Takahashi, M., Kondo, N., Ushito, D. and Umino, M. (2007), Haemodynamic changes and heart rate variability during midazolam-propofol co-induction. Anaesthesia, 62: 561–568. doi: 10.1111/j.1365-2044.2007.04990.x
- Issue online: 14 MAY 2007
- Version of Record online: 14 MAY 2007
- Accepted: 17 December 2006
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 intuba-tion (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−1propofol 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.