Circulatory response to laryngoscopy and tracheal intubation with or without prior oropharyngeal viscous lidocaine.

Oropharyngeal topical anesthesia with viscous lidocaine (25 ml of 2% as a "mouthwash and gargle" 10 min before laryngoscopy) attenuated the pressor but not heart rate (HR) response during laryngoscopy and tracheal intubation. Compared with control patients, mean arterial pressure (MAP) increased less in response to tracheal intubation (23 +/- 5 torr versus 39 +/- 4 torr, p less than 0.05) and returned toward awake levels sooner in patients receiving viscous lidocaine. MAP increased more than 40 torr in response to intubation in 6/20 patients treated with viscous lidocaine, while 12/20 control patients manifested this degree of blood pressure elevation. HR increased about 20 bpm (p less than 0.05) with or without viscous lidocaine. Arterial lidocaine concentrations were less than 0.5 microgram/ml after oropharyngeal anesthesia. Prior topical anesthesia of the oropharynx with viscous lidocaine should be considered when pressor responses during tracheal intubation would be particularly likely or hazardous.