Bolus dose remifentanil for control of haemodynamic response to tracheal intubation during rapid sequence induction of anaesthesia

The effect of three bolus doses of remifentanil on the presser response to laryngoscopy and tracheal intubation during rapid sequence induction of ana esthesia was assessed in a randomized, double-blind, placebo-controlled stu dy in four groups of 20 patients each. After preoxygenation, anaesthesia wa s induced with thiopental 5-7 mg kg(-1) followed immediately by saline (pla cebo) or remifentanil 0.5, 1.0 or 1.25 mu g kg(-1) given as a bolus over 30 s. Cricoid pressure was applied just after loss of consciousness. Succinyl choline 1 mg kg(-1) was given for neuromuscular block. Laryngoscopy and tra cheal intubation were performed 1 min later. Arterial pressure and heart ra te were recorded at intervals until 5 min after intubation. Remifentanil 0. 5 mu g kg(-1) was ineffective in controlling the increase in heart rate and arterial pressure after intubation but the 1.0 and 1.25 mu g kg(-1) doses were effective in controlling the response. The use of the 1.25 mu g kg(-1) dose was however, associated with a decrease in systolic arterial pressure to less than 90 mm Hg in seven of 20 patients.