Evaluation of the Cerebral State Index in Cats under Isoflurane Anaesthesia: Dose-Effect Relationship and Prediction of Clinical Signs

Table 3

Number of cats that achieved each anaesthetic plane for each end-tidal isoflurane (EtIso—%) concentration studied.

EtIso—%	Ocular reflexes	Attributed numerical scale	Number of cats that achieved the plane/total number of cats
0.8	PR+/CR+/EC	1	10/10
1.2	PR+/CR+/EC	1	7/10
	PR+/CR+/EV	2	1/10
	PR−/CR−/EV or EC	3	2/10
1.6	PR+/CR+/EC	1	1/10
	PR+/CR+/EV	2	1/10
	PR−/CR−/EV or EC	3	8/10
2.0	PR−/CR−/EV or EC	3	10/10

A numerical scale was attributed from 1 to 3 according to the anaesthetic depth based on the presence (+) or absence (−) of ocular reflexes and the position of the eye: PR: palpebral reflex; CR: corneal reflex; EC: eyeball centred in the eye; EV: eyeball rotated ventrally.
EtIso: end-tidal isoflurane concentration; numerical scale attributed according to the ocular reflexes observed.