after premedication with morphine and scopolamine , patients received either fentanyl 100 micrograms x kg-1 ( n = 16 ) , or sufentanil 15 micrograms x kg-1 ( n = 17 ) , intravenously ( iv ) over 10 min to induce anaesthesia .
C0015846
fentanyl
C0143993
sufentanil