Feasibility of bispectral index-guided propofol infusion for flexible bronchoscopy sedation: a randomized controlled trial

Abstract

Objectives: There are safety issues associated with propofol use for flexible bronchoscopy (FB). The bispectral index (BIS) correlates well with the level of consciousness. The aim of this study was to show that BIS-guided propofol infusion is safe and may provide better sedation, benefiting the patients and bronchoscopists.

Methods: After administering alfentanil bolus, 500 patients were randomized to either propofol infusion titrated to a BIS level of 65-75 (study group) or incremental midazolam bolus based on clinical judgment to achieve moderate sedation. The primary endpoint was safety, while the secondary endpoints were recovery time, patient tolerance, and cooperation.

Results: The proportion of patients with hypoxemia or hypotensive events were not different in the 2 groups (study vs. control groups: 39.9% vs. 35.7%, p = 0.340; 7.4% vs. 4.4%, p = 0.159, respectively). The mean lowest blood pressure was lower in the study group. Logistic regression revealed male gender, higher American Society of Anesthesiologists physical status, and electrocautery were associated with hypoxemia, whereas lower propofol dose for induction was associated with hypotension in the study group. The study group had better global tolerance (p<0.001), less procedural interference by movement or cough (13.6% vs. 36.1%, p<0.001; 30.0% vs. 44.2%, p = 0.001, respectively), and shorter time to orientation and ambulation (11.7±10.2 min vs. 29.7±26.8 min, p<0.001; 30.0±18.2 min vs. 55.7±40.6 min, p<0.001, respectively) compared to the control group.

Conclusions: BIS-guided propofol infusion combined with alfentanil for FB sedation provides excellent patient tolerance, with fast recovery and less procedure interference.

Trial registration: ClinicalTrials. gov NCT00789815.

Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.

Figures

Figure 1. Patient disposition.

BIS, bispectral index; VAS, verbal analogue scale.

Figure 2. The mean lowest oxygen saturation and blood pressure in both groups.

Boxes represent median and inter-quartile range; whiskers represent range. BIS, bispectral index; SpO2, oxyhemoglobin saturation; MAP, mean arterial blood pressure; SBP, systolic blood pressure; DBP, diastolic blood pressure.

Figure 3. Patient cooperation was accessed by procedural interference during bronchoscopy (A) and patient tolerance of procedure-related symptoms and global tolerance during bronchoscopy was accessed by verbal analogue scale (VAS) (B).

A: Interference by patient movement: The bronchoscopist had to temporarily pause the procedure and the assistants had to restrain the patient. Interference by patient coughing: The bronchoscopist had to pause the procedure temporarily and additional xylocaine spray and/or alfentanil had to be administered to stop the coughing. *p<0.001 vs. clinically-judged midazolam; #p = 0.001 vs. clinically-judged midazolam. B: After recovery, patient tolerance was evaluated by VAS (0: no bother, 10: worst intolerable). Data are presented as accumulative percentage of VAS in each group. A lower VAS score indicates better tolerance.