Effects of halothane on intraoperative scalp-recorded somatosensory evoked potentials to posterior tibial nerve stimulation in man.
Somatosensory evoked potentials (SEPs) were monitored in 116 patients receiving halothane anesthesia during spinal fusion surgery. Whereas it has been generally assumed that the use of halogenated inhalational anesthetics should be avoided with SEP monitoring because of their purported deleterious effects on scalp-recorded sensory responses, we found that reproducible SEPs were obtained throughout the surgical procedure in 91% of the cases we monitored while using halothane at concentrations of 0.25-2.0%. In those cases in which halothane was delivered continuously at 0.5%, reproducible evoked responses were recorded in 96% (75 of 78) of the patients. Our data demonstrated 3 major effects of halothane on the SEP: (a) a small but significant decrease in the average amplitude of the first two components (N25 and P30), (b) a significant increase in the average latency of the late positive component (P53) of the wave form, and (c) occasional obliteration of components N25, N40, P53, and N71, but never of P30. These effects did not, in most cases, interfere with our ability to obtain clinically useful recordings. Our results suggest that in many instances the use of halothane anesthesia can be combined successfully with the recording of intraoperative SEPs.
S K
SK
Salzman
A L
AL
Beckman
H G
HG
Marks
R
R
Naidu
W P
WP
Bunnell
G D
GD
MacEwen
D004558:Electric Stimulation; D005073:Evoked Potentials, Somatosensory / Q000187:drug effects*; D006221:Halothane / Q000494:pharmacology*; D006801:Humans; D007432:Intraoperative Period; D009994:Osmolar Concentration; D011930:Reaction Time; D013122:Spinal Diseases / Q000503:physiopathology / Q000601:surgery; D013123:Spinal Fusion; D013979:Tibial Nerve / Q000503:physiopathology*
D006221:Halothane