Background: Even with an adequate pain assessment, critically ill patients under sedation experience pain during procedures in the intensive care unit (ICU). We evaluated the effects of adjunctive administration of Remifentanil, a short-acting drug, in deeply sedated patient on variation of Bispectral Index (BIS) during a fiberoptic bronchoscopy.

Methods: A prospective, randomized, blinded, placebo-controlled study was conducted in 18-bed ICU. Patients needing a tracheal fibroscopy under deep sedation (midazolam (0.1 mg/kg per hour) fentanyl (4 μg/kg per hour)) and neuromuscular blocking (atracurium 0.5 mg/kg) were included in the study. A continuous monitoring of BIS, arterial pressure, and heart rate were realized before, during, and after the fiberoptic exam. An adjunctive continuous placebo or Remifentanil infusion was started just before the fiberoptic exam with a target effect-site concentration of 4 ng/ml using a Base Primea pump.

Results: Mean arterial pressure and heart rates were comparable between the placebo and Remifentanil groups at all times of the procedure. We did not observe differences in the variation of BIS values between the two groups during procedure. We described no change in BIS values relative to the placebo group in this population.

Conclusions: In deeply sedated and paralyzed patients, receiving analgesic support based on a scale score an additional administration of short-acting analgesic drug, such as Remifentanil, seems not to be necessary for acute pain control.

Trial registration: NCT00162591.