Table 3.

Correlation between ETAG-sevo with BIS and ETAG-sevo with (Fi−Et) O2% at various time intervals

ETAG-sevo(%)	BIS (R2)	(Fi−Et) O2% (R2)
Intubation	0.273	0.372**
Maintenance
15 min	0.285	0.306
30 min	0.017	0.087
Last 15 min of surgery	0.069	0.575*
End of surgery	0.286	0.561**
Extubation	0.235	0.296
Recovery	0.090	0.118

ETAG-sevo (%) – End-tidal anaesthetic concentration for sevoflurane; BIS – Bispectral index; (Fi−Et) O2% – Difference in inspired-end-tidal O2 concentration; R² – Pearson’s correlation coefficient **Correlation is significant at the 0.01 level; *Correlation is significant at the 0.05 level