forty patients undergoing gynaecological surgery were randomly assigned to receive either alfentanil and thiopentone for induction of anaesthesia , followed by alfentanil-n2o/o2 ( 60 % /40 % ) for maintenance of anaesthesia , or low-dose fentanyl and thiopentone , followed by enflurane-n2o/o2 ( 60 % /40 % ) .
C0002026
alfentanil
C0015846
fentanyl