The effects of temperature, halothane concentration, and arterial partial pressure of CO2 on corticomotor evoked potentials (CMEPs) and somatosensory evoked potentials (SSEPs) were studied. Hypothermia causes an increase in CMEP and SSEP latencies. Corticomotor evoked potential amplitude increases with hypothermia to reach a maximum at or below 28°C. As the temperature decreases from 42°C, SSEP amplitude initially increases to reach a maximum between 36 and 34°C and then decreases with further reductions in temperature. Increased arterial partial pressure of CO2 decreases amplitude and increases latencies of the CMEPs and SSEPs. The concentration of halothane has no effect on CMEP amplitude or latency. However, SSEP amplitude is inversely related to halothane concentration, and SSEP latency is directly related to halothane concentration. These results suggest that physiologic variables must be carefully measured when evoked potentials are utilized in any animal or human study. Moreover, each type of evoked potential has a unique response to alterations of these variables.
|Original language||English (US)|
|Number of pages||6|
|Journal||Anesthesia and Analgesia|
|State||Published - Jan 1 1992|
ASJC Scopus subject areas
- Anesthesiology and Pain Medicine