The results suggest that cardiac sympathectomy induced by epidural anesthesia can suppress partially baroreceptor function by interrupting sympathetic efferent fibers innervating the heart during high levels of epidural anesthesia, but that lumbar sympathectomy during epidural anesthesia is unlikely to affect baroreceptor activity.
Anesth Analg 1983; 62:815-820
http://www.anesthesia-analgesia.org/cgi/content/abstract/62/9/815