Intravenous administration of isosorbide dinitrate attenuates the pressor response to laryngoscopy and tracheal intubation

Abstract

In order to evaluate the effect of isosorbide dinitrate (ISDN), administered as a bolus intravenous injection on the circulatory response to tracheal intubation, mean arterial pressure (MAP), and heart rate (HR) in response to laryngoscopy for 30 s followed by tracheal intubation were compared in patients not receiving ISDN (control) and receiving 40 .mu.g/kg or 80 .mu.g/kg of ISDN 45 s before starting laryngoscopy. Each group consisted of 10 patients undergoing elective surgery. Forty-five seconds after starting laryngoscopy, MAP was significantly (P < 0.01) lower in patients receiving 80 .mu.g/kg ISDN than in those receiving no or 40 .mu.g/kg ISDN. HR increased to a similar extent in the three groups. These results indicate that a bolus injection of ISDN (80 .mu.g/kg) is a simple, practical and highly effective means of attenuating the hypertensive response to direct laryngoscopy and tracheal intubation.