Bispectral index-guided administration of anaesthesia: comparison between remifentanil/propofol and remifentanil/isoflurane.
OBJECTIVE
The bispectral index of the electroencephalogram is a measure of the hypnotic component of anaesthesia and can be used to guide the administration of anaesthesia. This study compares bispectral index-guided anaesthesia with remifentanil and either propofol or isoflurane.


METHODS
Eighty consenting patients were randomly assigned to two groups. Following induction with propofol and remifentanil, anaesthesia was maintained with remifentanil/propofol or remifentanil/isoflurane. Remifentanil infusion rates were guided by haemodynamic responses--maintaining mean arterial pressure and heart rate within 20% of baseline. Propofol and isoflurane administration was guided using the bispectral index (45-60). Thirty minutes before the end of surgery, morphine was administered (0.15 mg kg(-1) intravenously). Fifteen minutes before end of surgery, propofol and isoflurane were reduced (bispectral index 60-75). At the end of surgery, the anaesthetic agents were discontinued. Groups were compared for recovery, remifentanil doses and signs of inadequate anaesthesia using the chi2-test and ANOVA (P < 0.05).


RESULTS
The duration of surgery was longer in the propofol/remifentanil group (121 +/- 53 versus 94 +/- 40 min). Recovery data were not different between groups. The remifentanil infusion rate was significantly lower with additional isoflurane (0.18 +/- 0.06 microg kg(-1) min(-1)) than with additional propofol (0.31 +/- 0.20 microg kg(-1) min(-1)). The propofol infusion rate was 123 +/- 48 microg kg(-1) min(-1); isoflurane concentration was 0.66 +/- 0.13%.


CONCLUSIONS
Bispectral index-guided anaesthesia with remifentanil plus propofol or isoflurane results in the absence of postoperative recall and a fast recovery with both drug combinations. In our patients, at comparable bispectral index-levels, haemodynamic control requires higher doses of remifentanil with propofol than with isoflurane.
Schneider
G
G
Emory University School of Medicine, Department of Anesthesiology, Atlanta, GA 30335-3801, USA.
Elidrissi
C
C
Sebel
P S
PS
D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D000768:Anesthesia, General; D019162:Anesthetics, Combined / Q000008:administration & dosage / Q000627:therapeutic use; D018685:Anesthetics, Inhalation / Q000008:administration & dosage / Q000627:therapeutic use; D018686:Anesthetics, Intravenous / Q000008:administration & dosage / Q000627:therapeutic use; D004569:Electroencephalography; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007530:Isoflurane / Q000008:administration & dosage* / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D010880:Piperidines / Q000008:administration & dosage* / Q000627:therapeutic use; D015742:Propofol / Q000008:administration & dosage* / Q000627:therapeutic use; D000077208:Remifentanil; D013997:Time Factors
D019162:Anesthetics, Combined; D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; D010880:Piperidines; D007530:Isoflurane; D000077208:Remifentanil; D015742:Propofol