Automatic administration of propofol and remifentanil guided by the bispectral index during rigid bronchoscopic procedures: a randomized trial

Abstract

Background: Anesthesia for rigid bronchoscopic procedures is a demanding procedure. Automatic titration of propofol and remifentanil to maintain the bispectral index (BIS) within the recommended range (40-60) has been reported during routine surgical procedures. The aim of the present study was to evaluate its use during rigid bronchoscopy.

Methods: Patients were enrolled in a randomized study comparing manual target-controlled infusion of propofol and remifentanil (manual TCI group) with automatic titration guided by the BIS (dual-loop group). Categorical variables were compared by the Fisher's exact test, and continuous variables (median [interquartile range 25-75]) were compared by the Mann-Whitney test.

Results: Thirty-four patients were included in the manual TCI group and 33 were included in the dual-loop group. Baseline characteristics were well balanced between the groups. Intervention by the anesthesiologist in charge to modify propofol and/or remifentanil targets in the dual-loop group was not necessary. Percentage of time spent in the BIS interval (40-60) was similar in the manual TCI and dual-loop groups (69% [48-79] vs 70% [58-80], respectively). Durations of induction and of maintenance and propofol and remifentanil doses were also similar between groups, except for the amount of propofol needed for induction (P = 0.002). Time to tracheal extubation was also similar. No case of intraoperational awareness was detected.

Conclusion: The present study could not establish the superiority of automatic system over manual adjustment for bronchoscopy. Further studies with a different design and a larger number of patients are required to establish the place of automatic delivery of anesthetic agents. This study was registered at ClinicalTrials.gov number, NCT00571181.