Propofol infusion with or without fentanyl supplementation for microlaryngoscopy.

20 patients (ASA I to III) scheduled for microlaryngoscopy were randomly allocated to receive by infusion either 12-15 mg/kg/h propofol alone (group A) or 6-9 mg/kg/h with fentanyl supplementation (group B). All patients were premedicated with oral diazepam one hour before the procedure; they received an induction dose of 2 mg/kg propofol, preceded in group B by a bolus dose of fentanyl 1 microgram/kg. Significant hypotension was observed at induction in both groups to a similar degree (A:--26%; B:--30.2% compared to baseline). Placement of the laryngoscope induced sustained hypertension throughout the procedure in both groups (A: +28%; B: +20%) subsiding only at the removal of the instrument. Heart rate was never significantly altered. Arterial blood concentrations of propofol at induction reached high peak values (A: 16.82 +/- 8.52 micrograms/ml--B: 19.52 +/- 8.87 micrograms/ml--mean +/- SD) then remained stable throughout the procedure (A: 5.44 +/- 1.40 micrograms/ml--B: 2.91 +/- 1.06 micrograms/ml). At awakening, they were lower in group B (0.62 +/- 0.2 micrograms/ml) than in group A (1.17 +/- 0.55 micrograms/ml--p less than 0.05). Recovery was a little faster in group A (at the limit of significance). Though patients may present some excitation at awakening, recovery was usually very pleasant and characterized by swift return to consciousness, alertness and of all reflexes. We conclude that a propofol infusion is particularly suitable for microlaryngeal surgery. The addition of a narcotic agent allows reduction of the propofol dose range and does not alter recovery significantly. The proper dose of narcotic agent necessary to abolish cardiovascular reactivity to laryngoscopy must still be ascertained.