Definition
Inhalational anesthetics (halogenated anesthetics and nitrous oxide) decrease the amplitudes and increase the latency of SSEPs in a dose-dependent manner. (1)
Midazolam has little effect below 150mcg/kg.
Propofol has minimal effects between 120-200mcg/kg/min
Ketamine and Etomidate are acceptable as well. (2)
Opioids have minimal effects on SSEPs or MEPs.
At higher doses: (3)
- Etomidate increasesboth amplitude and latency.
- Thiopental decreasesamplitude and increases
- Midazolam hasno effect on amplitude but increases
Dexmedetomidine has minimal effects on SSEP monitoring. (4)
References
- Effects of desflurane and sevoflurane on somatosensory-evoked and motor-evoked potential monitoring during neurosurgery: a randomized controlled trial. PMID: 34620093
- Recommendations of the International Society of Intraoperative Neurophysiology for intraoperative somatosensory evoked potentials. PMID: 30470625
- Effects of etomidate, midazolam, and thiopental on median nerve somatosensory evoked potentials and the additive effects of fentanyl and nitrous oxide. PMID: 3364762
- Motor and somatosensory evoked potentials are well maintained in patients given dexmedetomidine during spine surgery. PMID: 18719439
- Recommendations of the International Society of Intraoperative Neurophysiology for intraoperative somatosensory evoked potentials.
Keyword history
68%/2009
Updated definition: 1/24/22
Author: David McDonagh, MD