Observation of anesthesia depth in severe burn patients with target controlled infusion of propofol and remifentanil by bispectral index / 解放军医学杂志

ABSTRACT

Objective To evaluate the feasibility and efficiency of bispectral index (BIS) for monitoring the anesthesia depth of severe burn patients with target controlled infusion (TCI) of propofol and remifentanil. Methods A total of 80 severe burns patients undergoing eschar excision (<1week) were randomly divided into BIS group (group A) and control group (group B), with 40 cases assigned in each group. These patients were 18 years to 65 years old, ASAII-III. Their total burn surface areas (TBSA) were from 31% to 50%, or 11% to 20% with three-degree burns. All patients received remifentanil and propofol for TCI intravenous anesthesia. The mean arterial pressure (MAP) and heart rate (HR) were determined at following time points, namely, entrance to the operation room, loss of consciousness, 2min after intubation, before surgery, 2, 15, and 30min after the start of surgery, end of surgery, eye opening, and period when Aldrete score reaching 9 points, as well as the target concentrations of remifentanil and propofol. The time frames from stoppage of drug infusion to eye opening and the period when Aldrete score reaching 9 points were also recorded. Results Compared with group B, the target concentrations of remifentanil (2.12 0.35ng/ml vs. 2.50 0.21ng/ ml) and propofol (2.54 0.22μg/ml vs. 2.86 0.31μg/ml) were significantly lower in group A during anesthetic maintenance (P<0.01). The time interval from stoppage of drug infusion to eye opening (7.90 0.58min vs. 8.35 0.66min) and period when Aldrete score reaching 9 points (9.15 0.69min vs. 11.13 0.96min) were significantly reduced in group A. The MAP of both groups from loss of consciousness at all time points, except 2min after intubation, was significantly lower than the basic values upon entrance into the operation room (P<0.05). The HR at all time points were significantly lower compared with the basic data (P<0.05). Conclusion BIS for monitoring the anesthetic depth of severe burns patients with TCI of propofol and remifentanil is helpful in reducing the dosage of propofol and in shortening the time for the patients to regain consciousness.