Objective: To observe the relationship between the level of catecholamine in plasma with bispectral index during endotracheal intubation with propofol anesthesia in order to investigate the mechanism of the preventing of endotracheal intubation response with esmolol.
Methods: Thirty patients were randomly allocated into two groups: control group (n=15) and esmolol group (n=15). The patients received esmolol 1amg/kg followed by 250 microg/(kgdmin) in esmolol group and saline in control group. Two minutes later, the patients received propofol 2amg/kg for induction. Bispectral index (BIS), systolic pressure (SP), diostolic pressure (DP), and heart rate (HR) were measured before endotracheal intubation and 3amin after intubation, at the same time 8a mL arteral blood was taken for the measurement of the concentrations of norephinephrine(NE) and ephinephrine(E) in plasma.
Results: The level of BIS(63.53+/-3.11), NE(2.016+/-0.681)and E(0.578+/-0.072)in control group 3 min after endotracheal intubation were increased significantly than those before intubation (P<0.05), but there were no significant change in the level of BIS, NE and E in esmolol group 3amin after endotracheal intubation . There were significant differences in the concentrations of NE(2.016+/-0.681)and E(0.578+/-0.072) in plasma 3 min after intubation between the two groups (P< 0.05) and there were also significant differences in BIS(63.53+/-3.11) and DeltaBIS(20.93+/-4.57)3 min after intubation between the two groups(P<0.01). SP( 148+/-20)and HR(89+/-180) in control group were increased after intubation than those before intubation (P<0.05) . There were no significant differences in SP, DP and HR in esmolol group after intubation than those before intubation.
Conclusion: Esmolol can reduce the plasma concentrations of NE and E through preventing periopheal sympathetic nerve response to intubation and can reduce BIS arousal reactions after endotracheal intubation.