A high level of neuroaxial block may produce profound bradycardia and hypotension, possibly as a result of an imbalance between sympathetic and parasympathetic control of heart rate.
Our results indicate that cervical, but not lumbar, epidural anesthesia depresses phasic and tonic dynamic modulation of the cardiac cycle by the vagal nerve in conscious humans.
IMPLICATIONS: Cervical epidural anesthesia with lidocaine produces depressed heart rate variability and baroreflex control of heart rate, whereas lumbar epidural anesthesia exerts minimal effects on autonomic nervous system activity in conscious humans.
Anesth Analg 2004;99:924-929
© 2004 International Anesthesia Research Society
doi: 10.1213/01.ANE.0000131966.61686.66
REGIONAL ANESTHESIA
The Effects of Cervical and Lumbar Epidural Anesthesia on Heart Rate Variability and Spontaneous Sequence Baroreflex Sensitivity
Makoto Tanaka, MD, Toru Goyagi, MD, Tetsu Kimura, MD, and Toshiaki Nishikawa, MD