[Effect of continuous infusion of diltiazem on cardiovascular responses to laryngoscopy and intubation].

We studied the cardiovascular responses to laryngoscopy and intubation in 30 patients who received continuous infusion of either diltiazem 10 micrograms.kg-1.min-1, 40 micrograms.kg-1.min-1 or saline as control group during 20 min before induction. Heart rate, arterial pressure, rate pressure product (RPP), pressure rate quotient (PRQ) were measured starting 20 min before induction to 3 min after tracheal intubation. The increases in arterial pressure and RPP following tracheal intubation were reduced significantly in patients receiving diltiazem 40 micrograms.kg-1.min-1, but they were not reduced in patients receiving diltiazem 10 micrograms.kg-1.min-1 compared with control. We conclude that continuous infusion of diltiazem during 20 min before induction is effective for preventing the increases in arterial pressure and RPP following tracheal intubation, and the optimal infusion rate is from 10 to 40 micrograms.kg-1.min-1.