Skin conductance monitoring compared with bispectral index monitoring to assess emergence from general anaesthesia using sevoflurane and remifentanil.
BACKGROUND
Changes in skin conductance have previously been reported to correlate well with plasma levels of stress hormones and awakening stimuli. In this study, monitoring of skin conductance during emergence from general anaesthesia was compared with the monitoring of bispectral index (BIS).


METHODS
Twenty-five patients undergoing minor elective surgery were investigated. The number of fluctuations in mean skin conductance (NFSC), BIS and haemodynamic parameters were recorded simultaneously. The performance of the monitoring devices to predict and distinguish between the clinical states 'steady-state anaesthesia', 'first reaction' and 'extubation' were compared using the method of prediction probability (P(K)) calculation.


RESULTS
Both monitors showed similar performance in distinguishing between 'steady-state anaesthesia' vs 'first reaction' (P(K) NFSC 0.89; BIS 0.94) and 'steady-state anaesthesia' vs 'extubation' (P(K) NFSC 0.96; BIS 0.96). The response times of the monitors, to indicate the likelihood of 'first reaction', were not significantly different.


CONCLUSIONS
NFSC, as a parameter of skin conductance, performed similarly to BIS in patients waking after a general anaesthetic.
Ledowski
T
T
Department of Anaesthesia and Pain Medicine, Royal Perth Hospital, Perth, Australia. thomas.ledowski@health.wa.gov.au
Paech
M J
MJ
Storm
H
H
Jones
R
R
Schug
S A
SA
D000293:Adolescent; D000328:Adult; D000368:Aged; D000768:Anesthesia, General / Q000379:methods*; D000777:Anesthetics; D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; D004569:Electroencephalography / Q000379:methods; D005260:Female; D005712:Galvanic Skin Response; D006801:Humans; D007442:Intubation, Intratracheal; D017214:Laryngeal Masks; D008297:Male; D008738:Methyl Ethers; D008875:Middle Aged; D013511:Minor Surgical Procedures; D008991:Monitoring, Physiologic / Q000379:methods; D010880:Piperidines; D011930:Reaction Time; D000077208:Remifentanil; D000077149:Sevoflurane
D000777:Anesthetics; D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; D008738:Methyl Ethers; D010880:Piperidines; D000077149:Sevoflurane; D000077208:Remifentanil