Movement response to skin incision: analgesia vs. bispectral index and 95% spectral edge frequency.
We studied the movement response to skin incision in 68 adult (males/females) ASA I-II patients receiving propofol +/- fentanyl intravenous anaesthesia using the bispectral index and 95% spectral edge frequency monitoring with an A-1050 EEG monitor. Following Ethics Committee approval, patients were randomly assigned to one of the following four treatments: Group P (n = 17): propofol infusion, 1 mg kg-1 min-1 intravenous for 2 min, followed by propofol infusion, 200 micrograms kg-1 min-1, until skin incision; Group PF1 (n = 17): fentanyl bolus, 1 microgram kg-1 intravenous + propofol infusion as in Group P; Group PF2 (n = 17): fentanyl bolus, 2 micrograms kg-1 intravenous + propofol infusion as in Group P; and Group PF3 (n = 17): fentanyl bolus, 3 micrograms kg-1 intravenous + propofol infusion as in Group P. The bispectral index and 95% spectral edge frequency were monitored continuously and recorded prior to induction of anaesthesia (base-line) and at skin incision. Twelve, 10, 4 and 4 patients responded to skin incision in Groups P, PF1, PF2 and PF3, respectively (P and PF1 vs. PF2 or PF3; P = 0.0001, and 0.006). The bispectral index and 95% spectral edge frequency were significantly lower at skin incision compared with the base-line values in all the four treatment groups. However, only bispectral index values were significantly lower in the nonmovement as compared with the movement (M) category (32.6 +/- 8.9 vs. 37.4 +/- 10.3; P = 0.04). Though deeper levels of hypnosis to lower bispectral index and 95% spectral edge frequency values may be effective in preventing the movement response to skin incision, provision of adequate analgesia rather than lower bispectral index and 95% spectral edge frequency (clinical maintenance) values may be more reliable for preventing the response to skin incision as bispectral index and 95% spectral edge frequency measure the hypnotic component of the anaesthetic effect. Lower bispectral index values may be more discriminatory as compared with 95% spectral edge frequency values for preventing the movement response to skin-incision.
Singh
H
H
Department of Anaesthesiology, University of Hirosaki School of Medicine, Japan.
Sakai
T
T
Matsuki
A
A
D000293:Adolescent; D000328:Adult; D000368:Aged; D000701:Analgesics, Opioid / Q000008:administration & dosage; D000771:Anesthesia, Intravenous; D018686:Anesthetics, Intravenous / Q000008:administration & dosage; D062109:Dermatologic Surgical Procedures; D004569:Electroencephalography / Q000187:drug effects; D005260:Female; D005283:Fentanyl / Q000008:administration & dosage; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D009068:Movement / Q000187:drug effects*; D015742:Propofol / Q000008:administration & dosage
D000701:Analgesics, Opioid; D018686:Anesthetics, Intravenous; D005283:Fentanyl; D015742:Propofol