Reversal of neuromuscular blockade by sugammadex does not affect EEG derived indices of depth of anesthesia.
OBJECTIVE
According to previous studies neuromuscular blockade may affect the depth of anesthesia. One theory states that neuromuscular blockade prevents disturbing EMG signals, arousing from the muscles of the forehead, from falsely elevating bispectral index (BIS)-levels. According to the afferentation theory signals generated in muscle stretch receptors, accessing the brain through afferent nerve pathways, induce arousal. By blocking these signals neuromuscular blockade would increase depth of anesthesia. Arousal has previously been associated with neostigmine reversal. This study investigates the possible effect of sugammadex on the level of anesthesia as defined by BIS and spectral entropy levels.


METHODS
Thirty elective patients were enrolled. All patients received propofol and remifentanil by target controlled infusion and an intermediate level neuromuscular blockade induced and maintained by bolus doses of rocuronium. Depth of anesthesia was monitored by BIS and spectral entropy. The patients were given 2 mg/kg sugammadex 5 min after finishing of surgery. Propofol and remifentanil infusions were kept unchanged for another 10 min while BIS and entropy values were recorded.


RESULTS
Mean BIS and Entropy™ values remained unchanged after reversal of the rocuronium block. The mean averaged BIS, state entropy and response entropy values were 31.7 ± 9.9, 35.3 ± 12.9 and 36.8 ± 13.3 before and 32.0 ± 11.9, 36.3 ± 15.9 and 38.4 ± 18.0 after sugammadex administration, respectively.


CONCLUSIONS
Sugammadex does not affect level of anesthesia as determined by BIS or entropy levels.
Illman
Hanna
H
Department of Anesthesiology, Intensive Care, Emergency Care and Pain Medicine, Turku University Hospital, P.O. Box 52, Kiinamyllynkatu 4-8, 20520 Turku, Finland. hanna.illman@tyks.fi
Antila
Heikki
H
Olkkola
Klaus T
KT
D000328:Adult; D000732:Androstanols / Q000008:administration & dosage; D000758:Anesthesia / Q000379:methods* / Q000706:statistics & numerical data; D001143:Arousal / Q000187:drug effects; D004569:Electroencephalography / Q000706:statistics & numerical data*; D005072:Evoked Potentials, Auditory / Q000187:drug effects; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000706:statistics & numerical data; D019148:Neuromuscular Blockade / Q000379:methods*; D009466:Neuromuscular Blocking Agents / Q000008:administration & dosage; D010880:Piperidines / Q000008:administration & dosage; D015742:Propofol / Q000008:administration & dosage; D000077208:Remifentanil; D000077123:Rocuronium; D012815:Signal Processing, Computer-Assisted; D000077122:Sugammadex; D047408:gamma-Cyclodextrins / Q000008:administration & dosage*
D000732:Androstanols; D009466:Neuromuscular Blocking Agents; D010880:Piperidines; D047408:gamma-Cyclodextrins; D000077122:Sugammadex; D000077208:Remifentanil; D000077123:Rocuronium; D015742:Propofol