Effects of tracheal spray of lidocaine on arterial pressure and heart rate during laryngoscopy for endotracheal intubation

Changes in mean arterial blood pressure (MAP) and heart rate (HR) were observed in 30 normotensive patients scheduled for elective general surgical operations. These patients were divided into three treatment groups. Group 1: endotracheal intubation without lidocaine spray, Group 2: intubation with tracheal spray of 4% lidocaine (2 ml), Group 3: intubation with tracheal spray of 1.6% lidocaine (5 ml). Compared with pre-induction values, in group 1, MAP increased 26% and HR increased 16% in response to direct laryngoscopy, but MAP increased 60% and HR increased 46% in response to intubation. In both group 2 and group 3, MAP increased 46% and HR increased 27% after lidocaine spray, but MAP increased 27% after lidocaine spray, but MAP increased 55% and HR increased 27% in response to intubation. The average lidocaine blood level in group 2 and group 3 was less than 1 μg/ml at the time of tracheal intubation. Although endotracheal intubation markedly increased arterial pressure and heart rate, tracheal spray itself also increased them. The magnitude of these hemodynamic responses following intubation was not altered by tracheal lidocaine spray. These results suggest that lidocaine spray is not useful for prevention of hemodynamic changes during tracheal intubation, nor does it change arterial blood pressure and heart rate.