['To explore the effect of intravenous injection rate and site of fentanyl on the incidence and onset time of fentanyl-induced cough.', 'Seventy-five ASA class I or II patients were randomized into 3 groups and received intravenous fentanyl administration at 4 microg/kg in different manners. In group A, fentanyl was injected within 2 s into the forearm veins; in group B, fentanyl was injected in 2 s through the dorsal foot veins or the great saphenous vein anterior to the ankle; in group C, fentanyl was injected in 15 s by the same route as in group A.', 'The incidence of cough was 44%, 52% and 8%, with cough onset time of 16.1-/+2.7 s, 21.9-/+3.7 s and 23.3-/+3.2 s in groups A, B and C, respectively. Compared with group A, group B had a delayed onset of cough (P<0.05), and group C had both a lowered incidence of cough (P<0.05) and delayed onset of cough (P<0.05).'] Do [ Intravenous injection rate and site of fentanyl affect the incidence and onset time of fentanyl-induced cough ]?