Table 3: Number of cats that achieved each anaesthetic plane for each end-tidal isoflurane (EtIso—%) concentration studied.

EtIso—%Ocular reflexesAttributed numerical scaleNumber of cats that achieved the plane/total number of cats

0.8PR+/CR+/EC110/10
1.2PR+/CR+/EC17/10
PR+/CR+/EV21/10
PR−/CR−/EV or EC32/10
1.6PR+/CR+/EC11/10
PR+/CR+/EV21/10
PR−/CR−/EV or EC38/10
2.0PR−/CR−/EV or EC310/10

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.