Impact of general anaesthesia on parameters of bulbocavernosus reflex

Abstract

Dysfunction of the pelvic organs in tumor lesions of the spinal cord is up to 20%. Registration of the bulbocavernosus reflex is performed to assess the integrity of the segmental apparatus of the spinal cord. Polymodal neurophysiological monitoring includes registration of the bulbocavernosus reflex during surgery of spinal cord tumors. The effect of the components of general anesthesia on the parameters of the bulbocavernosus reflex varies significantly according to various medical sources. The aim of the work was to compare the effect of inhalation anesthesia (sevoflurane) and total intravenous anesthesia (propofol) on the parameters of the bulbocavernosus reflex in the surgical treatment of spinal cord tumors. Thirty patients with intradural extramedullary and intramedullary tumors of the spinal cord at the level of Th11–S2 vertebrae were included in the study. The amplitude-frequency parameters of the bulbocavernosus reflex and the threshold intensity of stimulation were assessed in the study. The results of the study demonstrate that intraoperative registration of the bulbocavernosus reflex during resection of tumors of the distal spinal cord can be performed both with inhalation and total intravenous anesthesia. A sustained motor response of the bulbocavernosus reflex requires a higher intensity of stimulation with inhalation anesthesia with sevoflurane than with total intravenous anesthesia. If during the operation the depth of propofol's anesthesia increases by 1 mg/kg/h, then it is necessary to increase the current strength during stimulation by 10–11 mA.