The effects of remifentanil on haemodynamic stability during rigid bronchoscopy

Introduction

The hypothesis behind the present study was that remifentanil produces greater haemodynamic stability during rigid bronchoscopy than does the conventional propofol injection technique.

Method

This was a double-blind, parallel-group, randomized study. All patients received propofol (2-3 mg/kg) and rocuronium (0.6 mg/kg iv) at induction of anaesthesia. Patients then received either remifentanil (n =11; 1 μg/kg bolus over 1min followed by infusion of 0.5 μg/kg) or fentanyl (n =11; 2 μg/kg bolus followed by saline placebo infusion). Escape medications of propofol, atropine and ephedrine were given as required. Their lungs were ventilated with 100% oxygen via a Sanders' injector. Haemodynamic instability was defined as one of the following: lacrimation, sweating; systolic blood pressure =20 mmHg above or below preoperative baseline for 1 min; and heart rate >100 or <50 beats/min for 1 min.

Results and conclusion

There were no significant differences in patient characteristics nor duration of bronchoscopy between the two groups. Remifentanil was found to attenuate significantly the haemodynamic response to insertion of a rigid bronchoscope (P < 0.05 for increase in arterial pressure; P < 0.01 for increase in heart rate). During bronchoscopy, five patients showed somatic or autonomic responses in the fentanyl group, compared with none in the remifentanil group (P < 0.01). ST-segment changes occurred in eight patients in the fentanyl group compared with four patients in the remifentanil group (P < 0.05). The total doses of escape medications used and the total episodes of haemodynamic instability during bronchoscopy were significantly reduced in remifentanil infusion group.