The Effect of Bispectral Index Monitoring during Induction of Anesthesia on the Amount of Propofol Consumtion in Patients Candidates for Surgery

Introduction Propofol is a new intravenous hypnotic drug that is widely used in anesthesia and monitoring the depth of anesthesia. BIS is a parameter derived from electroencephalography that is associated with sleep deprivation and loss of consciousness. This study investigated the effect of Bispectral index (BIS) during induction of anesthesia on the amount of propofol consumed in patient candidates for surgery. Materials and Methods This double-blind clinical trial study was performed on patients undergoing elective surgery under general anesthesia in a hospital. Patients were divided into case and control groups. After being transferred to the operating room, patients were monitored including ECG 3 or 5 leads, non-invasive barometer and pulse oximetry. Mean arterial blood pressure and heart rate were measured before and after induction, immediately and 5 minutes after intubation. The dose of propofol was then measured. Data analysis was performed by SPSS software version 20. Results In the present study, no significant difference was found between the mean age and gender (P > 0.05). The amount of propofol consumed in the case group was significantly lower than the control group (P = 0.039) and the amount of propofol consumed in men and women was not statistically significant (P < 0.05). Mean arterial blood pressure before induction was not statistically significant between the two groups (P = 0.83). However, a statistically significant difference was found in the mean arterial blood pressure of the patients during the 4 time points (P = 0.001). There was no statistically significant difference in heart rate between patients before induction (P = 0.48). Statistical analysis of data by ANOVA test did not show a significant interaction between time and group (P = 0.418 and P = 0.74). However, a statistically significant difference was found in patients'heart rate during the 4 time points (F = 7.59 and P = 0.001). Moreover, a significant increase was observed in heart rate after intubation in both groups (P = 0.001). Conclusion The use of BIS can be effective in reducing the amount of propofol consumed and its side effects. The condition of patients under general anesthesia can be improved by BIS, resulting in improvement of their subsequent condition.