Comparative Effects of Lidocaine and Esmolol in Modifying the Hemodynamic Response to Laryngoscopy and Intubation

Aim: To compare the safety and efficacy of lidocaine and esmolol, in modifying the hemodynamic response to laryngoscopy and intubation. Design: Randomized, placebo-controlled, double-blind study was carried out in Fauji Foundation hospital Lahore from 1 st June 2012 to 31 st August 2012,after taking written informed consent from patients and permission from medical and ethical committee of hospital. Patients & methods: 60 ASA physical status I and II patients undergoing elective surgery with general endotracheal anesthesia. Anesthesia was induced with propofol 2.5 mg/kg, and intubation was facilitated with atracurium 0.5 mg/kg. Isoflurane (0.5% to 1%) and 50% nitrous oxide in oxygen were used for maintenance of anesthesia. In addition, patients received one of the following study drugs intravenously prior to laryngoscopy: Group 1 (control) = saline 5 ml; Group 2 = lidocaine 1.5 mg/kg; Group 3 = esmolol 1.5 mg/kg; Mean arterial pressure (MAP) and heart rate (HR) were recorded every minute for 20 minutes following induction of anesthesia after laryngoscopy and intubation. MAP increased significantly in all three treatment groups (control 47% +/15%, lidocaine 34% +/9%, esmolol 11% +/5 %,) compared with preinduction baseline values. In the esmolol-pretreated patients, the increase in HR was significantly lower (8% +/3%) compared with lidocaine (41% +/8%), and control (47% +/4%) groups. Conclusions: Lidocaine 1.5 mg/kg I.V was less effective in controlling the acute hemodynamic response following laryngoscopy and intubation. Esmolol 1.5 mg/kg I.V was significantly more effective than lidocaine in controlling the HR response to laryngoscopy and intubation (p <0.05). Esmolol also was significantly more effective than lidocaine in minimizing the increase in MAP (25% vs. 55%).