RESUMO
Abstract Introduction: Propofol is a new intravenous hypnotic drug that in combine with a short acting opioid have been used in total intravenous anesthesia [TIVA]. The BIS provides additional information for standard monitoring techniques to recognize depth of sleep and achieve the appropriate dose of drug
Objective: Comparison of different propofol dose for anesthesia induction based on BIS [bispectral index] monitoring
Materials and Methods: forty five patients with ASA class I, II who underwent surgical operation on leg fracture were randomly assigned to 3 groups. Group A with a propofol dose of 1mg/kg, Group B at a dose of 1.5mg/kg and Group C at a dose of 2mg/kg were studied. Remifentanyl [0.5mcg/kg] was added to propofol as opioid drug. The method of BIS index [50-60] has been used for determination of consciousness level and the depth of sleep and for achieving the appropriate dose of propofol. The patients were evaluated to determine occurrence of hypotension, bradycardia, the presence of intubation movement and the autonomic signs
Results: The mean levels of BIS was 58.8 +/- 9.85 in the Group A, 50.2 +/- 6.55 in Group B, and 44 +/- 5.65 in Group C. Comparison between the mean levels of BIS revealed that the Group A was significantly different with the other two groups [p=0.009]. Optimum level of BIS was significantly different in 3 groups .group B [%66.7], group A [%40], group C [%20], less than of all groups [P=0.034]. Hypertension incidence following intubation in group A was 33.3% and Group B was [%6.7] and in group C wasn't any hypertension which detected a significantly different between three groups [P=0.018]. Regarding to need further propofol dose, there was a significant difference [P<0.001]. In group A, it was in %40 of cases, and in groups B and C it was not observed. Regarding to tachycardia, bradycardia, hypotension, movement and autonomic signs, there was no significantly different between 3 groups
Conclusion: It was appeared that group A is not appropriate due to incompatible with BIS, need Further propofol dose and hypertension. Considering the best BIS level in group B and lack of any benefit in group C for further propofol in achieving the optimum level of BIS [50-60], can be concluded that group B with propofol [1.5mg/kg] is the best dose for achieving the desired level of BIS with remifentanil at the mentioned dose