Abstract
The beat-to-beat variabilities were analyzed by the maximum entropy spectral analysis during inhalation anesthesia with halothane and isoflurane in 6 dogs. As the anesthetic concentration increased, the frequencies and amplitudes of peaks and each area in the low and high frequency bands (0.02-0.09 Hz and over 0.15 Hz, respectively) changed. In addition, these alterations between isoflurane and halothane showed different patterns. It is concluded that power spectrum analysis of beat-to-beat variability during anesthesia may be a useful method as monitoring anatomic nervous activities to control the cardiovascular system.
