Effect of Administration Time of Lidocaine on the Cardiovascular Changes induced by Endotracheal Intubation

Im, Hyung Yoon; Jeong, Chang Young; Im, Woong Mo; Chung, Sung Su

Abstract

Intravenous lidocaine has been used for attenuating cardiovascular responses to endotracheal intubation. To determine the optimal time of administration of lidocaine for attenuating hemodynamic changes induced by intubation, 100 patients were allocated randomly to a control group (without lidocaine) or four treated groups (with lidocaine). Lidocaine 1.5 mg/kg was administered intravenously at 60 (Group 2), 90 (Group 3), 120 (Group 4) and 180 seconds (Group 5) before intubation. Arterial pressure (systolic, mean and diastolic), heart rate and rate-pressure product (RPP) were measured before induction, after lidocaine injection, immediatly before intubation, immediately and 5 minutes after intubation. After intubation, arterial pressure, heart rate and RPP increased significantly in every study groups. In group 2 and 3, however, such changes were attenuated significantly, Postintubation elevation of systolic blood pressure, mean arterial pressure and RPP were effectively prevented in group 2 and 3. Lidocaine effect on diastolic pressure was observed only in group 3. Changes of heart rate were not affected with lidocaine adminiistration. In Group 4 and Group 5, this effect was not observed. In diastolic pressure, suppressive effect of lidocaine in increasing of blood pressure and RPP was observed in Group 3 significantly, but not in Group 2, Group 3 and Group 5. Changes of heart rate show that in all groups injected lidocaine (Group 2,3,4,5) significantly suppressive effect was not observed as compared with control group. These results suggest that intravenous lidocaine (1.5 mg/kg), 60-90 second prior to intubation attenuate hemodynamic responses induced by intubation.