Neuromuscular block and the electroencephalogram during sevoflurane anaesthesia.
The effect of neuromuscular block on the anaesthetic depth of hypnosis is an elusive question. We simultaneously investigated the influence of neuromuscular block on the bispectral index, a measure of hypnosis during general anaesthesia, and on the electroencephalogram. Patients were anaesthetized with sevoflurane. Noxious tetanic electrical stimulation was applied on two occasions: before and after profound neuromuscular block achieved with rocuronium. Neuromuscular block significantly attenuated the effect from noxious stimulation on electroencephalogram power and synchrony in the gamma band (P<0.05), and the corresponding effect on bispectral index (P<0.02). These findings are probably due to the reduced arousing afferent input from paralysed muscles, and not to changes in the frontal electromyogram.
Ekman
Andreas
A
Department of Physiology and Pharmacology, Section for Anaesthesiology and Intensive Care Medicine, Karolinska Institutet, Stockholm, Sweden. andrease@ltkalmar.se
Flink
Roland
R
Sundman
Eva
E
Eriksson
Lars I
LI
Brudin
Lars
L
Sandin
Rolf
R
D000293:Adolescent; D000328:Adult; D000368:Aged; D000769:Anesthesia, Inhalation; D018685:Anesthetics, Inhalation; D003627:Data Interpretation, Statistical; D004558:Electric Stimulation; D004569:Electroencephalography / Q000187:drug effects*; D005260:Female; D006801:Humans; D008297:Male; D008738:Methyl Ethers; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D009213:Myography; D009466:Neuromuscular Blocking Agents / Q000494:pharmacology*; D010812:Physical Stimulation; D011446:Prospective Studies; D000077149:Sevoflurane
D018685:Anesthetics, Inhalation; D008738:Methyl Ethers; D009466:Neuromuscular Blocking Agents; D000077149:Sevoflurane