SSEP Latency: anesthetic drugs

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

1. Effects of desflurane and sevoflurane on somatosensory-evoked and motor-evoked potential monitoring during neurosurgery: a randomized controlled trial. PMID: 34620093
2. Recommendations of the International Society of Intraoperative Neurophysiology for intraoperative somatosensory evoked potentials. PMID: 30470625
3. Effects of etomidate, midazolam, and thiopental on median nerve somatosensory evoked potentials and the additive effects of fentanyl and nitrous oxide. PMID: 3364762
4. Motor and somatosensory evoked potentials are well maintained in patients given dexmedetomidine during spine surgery. PMID: 18719439
5. Recommendations of the International Society of Intraoperative Neurophysiology for intraoperative somatosensory evoked potentials.