[Effects of different doses of esmolol on cardiovascular responses to tracheal extubation].

OBJECTIVE: To observe the effects of different doses of esmolol on cardiovascular responses to tracheal extubation. METHODS: We randomly divided 175 patients undergoing elective surgery into 5 groups. Before the tracheal extubation, patients received 10 ml saline (group A), esmolol 0.5 mg/kg (group B), 1.0 mg/kg (group C), 1.5 mg/kg (group D) and 2.0 mg/kg (group E), respectively, and then the trachea was extubated 2 min later. Systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) were recorded at premedication, tracheal extubation, and 1, 3, 5, 10 min after the tracheal extubation. Rate-pressure product was derived from SBP x HR. RESULTS: Compared with those at premedication, the SBP, DBP, HR, and RPP of the patients in Group A increased significantly at the tracheal extubation and 1 min after the tracheal extubation (P < 0.01). The DBP, HR, and RPP of patients in Group B were significantly higher at the tracheal extubation (P < 0.01). The SBP, HR and RPP of patients in Group B decreased significantly at the tracheal extubation and 1 min after the tracheal extubation compared with those in Group A (P < 0.01). The SBP, DBP, HR and RPP of patients in Group C, D and E decreased significantly at the tracheal extubation compared with those in group A and B (P < 0.05); as well as SBP, HR, RPP of patients in Group C, D, E at 1 min after tracheal extubation compared with those of patients in group A. SBP in Group C, D; HR in Group D, E; RPP in Group C, D, E decreased significantly at 3 min after the tracheal extubation compared with those in Group A(P < 0.05). Compared with premedication, HR, RPP in Group D decreased significantly at 3-10 min after the tracheal extubation and in group E at tracheal extubation, 1-10 min after the tracheal extubation (P < 0.05), but three patients in group E had a bradycardia after receiving esmolol. CONCLUSION: Esmolol of 1.5 mg/kg may not only control cardiovascular responses more effectively to the tracheal extubation, but also has no side-effects.