the patients were randomly allocated to receive either high-dose alfentanil anaesthesia ( 150 micrograms kg-1 initially , followed by continuous infusion at a rate of 3 micrograms kg-1 min-1 ) or neurolept anaesthesia ( droperidol 0.25 mg kg-1 plus fentanyl 5 micrograms kg-1 initially , followed by intermittent incremental doses of fentanyl 50 micrograms ) .
C0002026
alfentanil
C0015846
fentanyl