Closed-loop control of consciousness during lung transplantation: an observational study.

Objective: To determine if propofol infusion can be steered automatically by using bispectral index (BIS) as a controller during lung transplantation.

Design: A prospective study of patients undergoing lung transplantation.

Setting: University hospital.

Participants: Twenty consecutive patients scheduled for bilateral (n = 14) or single (n = 6) lung transplantation.

Interventions: The goal of the closed-loop administration of propofol was to maintain the BIS value between 40 and 60 during the maintenance phase. The remifentanil infusion was adjusted according to standard clinical practice.

Measurements And Main Results: The closed-loop system was able to provide anesthesia maintenance for all patients. Cardiopulmonary bypass was used in 5 patients, and 14 patients received a thoracic epidural catheter. The BIS value was maintained between 40 and 60 during 84% +/- 16% of the maintenance phase. Eleven patients were extubated in the operating room, and 1 patient needed reintubation.

Conclusion: Closed-loop control of consciousness by a computer during lung transplantation is clinically feasible.