The Effects of Isoflurane and Desflurane Titrated to a Bispectral Index of 60 on the Cortical Somatosensory Evoked Potential During Pediatric Scoliosis Surgery

Abstract

In this study, we compared the effect of isoflurane and desflurane on the posterior tibial somatosensory evoked potential recorded by scalp electrodes during correction of idiopathic scoliosis in pediatric patients. Depth of sedation was controlled by maintaining bispectral index (BIS) at 60 throughout the study. Comparison of patients breathing desflurane and isoflurane showed an evoked cortical amplitude (N37-P45) of 0.53 +/- 0.3 microV versus 1.3 +/- 0.8 microV (P = 0.014), respectively. In addition to this comparison, a crossover design was included whereby the desflurane or isoflurane received in the first part of the study was changed to the other anesthetic. Substituting one anesthetic for another confirmed our initial finding that the cortical evoked amplitude is greater with isoflurane than with desflurane. No differential effect was found between desflurane and isoflurane on the evoked subcortical (N31-P34) amplitude or the P37 latency.

Monitoring Depth of Hypnosis: Mid-Latency Auditory Evoked Potentials Derived aepEX in Children Receiving Desflurane-Remifentanil Anesthesia

“…A sample size of 25 children per age group and the defined age groups correspond to similar published studies concerning DoH monitors. 6,16,17 Previous studies have assumed that a reliable P k value can be computed with a sample size of >20 patients. [18][19][20] January 2020…”

“…However, the EC 50 can also be measured by recording the end-tidal desflurane concentration while maintaining an index value of 50. Fletcher et al 17 performed such a study by maintaining a BIS of 60 during pediatric scoliosis surgery under desflurane anesthesia. The end-tidal concentration desflurane needed to maintain a BIS of 60 can be described as an EC 60 for the BIS monitor.…”

Variation of bispectral index monitoring in paediatric patients undergoing propofol-remifentanil anaesthesia

“…The BIS monitor has been used in children for a long time either during anaesthesia or in ICU. It is unclear, however, if this technology will be as fit for children as for adults [17][18][19][20][21]. We know that it is based on an algorithm developed from adults.…”

Desflurane Selectively Suppresses Long-latency Cortical Neuronal Response to Flash in the Rat

“…Desflurane’s effect on the electroencephalogram is similar to that of isoflurane 15–17 but the two agents may differ in their effect on somatosensory evoked potentials. This issue is currently controversial as isoflurane appears more suppressive at equi-minimum alveolar concentration levels with propofol as background anesthetic 18, whereas desflurane appears more suppressive at equi-bispectral index levels with no background anesthetic 19. Still others found no difference between the two agents’ effects 20,21.…”