Comparison of the effects of different anesthetic techniques on electrocorticography in patients undergoing epilepsy surgery - a bispectral index guided study.
OBJECTIVE
It is well known that general anesthetics suppress/alter electrocorticography (ECoG) activity. However there are no randomized studies available, comparing various anesthetic techniques as regards their effects on ECoG.


METHODS
The following is a double blind, randomized cross over study to compare the effects of isoflurane and propofol with or without nitrous oxide on electrocorticographic activity in patients undergoing epilepsy surgery. 40 patients suffering from medically intractable epilepsy scheduled to undergo resective surgery under ECoG guidance under general anesthesia, (March 2008-December 2010) were enrolled. Patients received either isoflurane or propofol (with air/oxygen or nitrous oxide/oxygen) as maintenance agents as per randomization and ECoG was recorded and quantified as per a scoring system (range 1-5, where 5 is most abnormal).


RESULTS
The mean ECoG score in isoflurane group and propofol with nitrous oxide was 3.0(1.2), 3.2(1.2) [p=0.7] and with air was 3.9(1.0) and 3.4(1.1) [p=0.1] respectively. In both isoflurane group and propofol group addition of nitrous oxide depressed the ECoG score (p ≤ 0.01, 0.5 respectively). The total duration of anesthesia, surgery, emergence time, extubation time, and hospital stay was comparable in two groups.


CONCLUSIONS
In our study optimal ECoG recordings were possible with use of either isoflurane or propofol. Addition of nitrous oxide to either of the anesthetic regimens suppressed the ECoG score.
Department of Neuroanaesthesiology, Neurosciences Center, All India Institute of Medical Sciences, New Delhi 110029, India.
Ashish
A
Bindra
Rajendra S
RS
Chouhan
Hemanshu
H
Prabhakar
Hari Har
HH
Dash
P Sarat
PS
Chandra
Manjari
M
Tripathi
D000293:Adolescent; D000328:Adult; D019162:Anesthetics, Combined / Q000008:administration & dosage*; D001921:Brain / Q000187:drug effects / Q000601:surgery; D002648:Child; D002675:Child, Preschool; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004569:Electroencephalography / Q000187:drug effects*; D004827:Epilepsy / Q000601:surgery*; D005260:Female; D006801:Humans; D007223:Infant; D007530:Isoflurane / Q000008:administration & dosage*; D008297:Male; D009609:Nitrous Oxide / Q000008:administration & dosage*; D015742:Propofol / Q000008:administration & dosage*; D055815:Young Adult
D019162:Anesthetics, Combined; D007530:Isoflurane; D009609:Nitrous Oxide; D015742:Propofol