Objective.To compare the effects of alfentanil and esmolol on hemodynamic and catecholamine response to tracheal intubation. Methods.Thirty five adult patients were randomly allocated to one of three groups

Group A（control group）

Group B（esmolol group）and Group C（alfentanil group）.The patients received either 2 mg/kg esmolol（in Group B）or 30 μg/kg alfentanil（in Group C）before intubation.Tracheal intubation was performed with 4 mg/kg thiopental and 0 1 mg/kg vecuronium and 3% isoflurane.Systolic blood pressure（SBP）

diastolic blood pressure（DBP）

mean blood pressure（MBP）

heart rate（HR）

norepinephrine（NE）

epinephrine（E）and dopamine（DA）were measured before and after intubation. Results.The control group had a baseline SBP of 149±23 mmHg while Groups B

C had a baseline SBP of 148±23

and 150±21mmHg

respectively（P>0 05）.Three min after tracheal intubation

the control group SBP increased to 160±30 mmHg and Group B remained at the baseline level

147±5 mmHg

and Group C significantly decreased to 91±22 mmHg（P<0 01）.Two min after intubation HR in Group B increased significantly but 3 min after intubation HR in Groups B and C were significantly lower than that of control group（P<0 05）.NE in Groups A and B increased significantly to 5 75±3 51 and 6 75±3 30 nmol/L 3 min after intubation（P<0 01）.In Group C

3 min after intubation NE was not significantly different from the baseline but E decreased significantly（P<0 01）. Conclusion.2 mg/kg esmolol can moderate the hemodynamic response to tracheal intubation to a certain extent and 30μg/kg alfentanil can completely attenuate the hemodynamic and catecholamine responses.