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

Table 1

Electroencephalographic parameters derived by the CSM and other physiologic data recorded at each end-tidal isoflurane concentration (EtIso—%) studied. The number of animals (𝑁) at each EtIso step is shown. Mean ± standard deviation is shown.

EtIso; (%)	𝑁	CSI	BS (%)	EMG (%)	SQI (%)	MAP (mmHg)	HR (bpm)	SpO2 (%)	EtCO2 (%)	RR (rpm)	𝑇 (°C)
0.8	10	51.6±23.9	14.3±23.8	25.6±28.5	79.5±15.8	88.6±30.6	163.0±28.8	98.3±1.3	36.7±6.5	32.3±12.7	37.4±0.4
1.2	4	36.1±28.3	36.2±42.0	16.6±14.1	81.2±12.8	66.3±14.4	138.3±24.8	97.0±1.2	36.5±6.6	20.0±2.9	37.1±0.3
1.6	10	29.4±13.5	25.7±25.9	3.0±8.5	84.3±20.4	68.0±24.3	140.2±31.3	98.2±1.0	39.1±5.8	19.6±6.6	37.2±0.3
2.0	7	17.0±17.7	60.9±32.8	0.2±0.6	91.0±11.6	65.4±13.1	144.3±24.8	98.1±1.3	42.6±6.1	19.1±6.3	37.2±0.6

EtIso: end-tidal isoflurane concentration; CSI: cerebral state index; BS: burst suppression (%); EMG: electromyographic activity (%); SQI: signal quality index (%); MAP: mean arterial pressure (mmHg); HR: heart rate (bpm); SpO₂: oxygen saturation of haemoglobin (%); EtCO₂: end-tidal carbon dioxide (%); RR: respiratory rate (rpm); 𝑇: temperature (°C).