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. 2013 Jul;57(4):351-7.
doi: 10.4103/0019-5049.118557.

Bispectral index score and observer's assessment of awareness/sedation score may manifest divergence during onset of sedation: Study with midazolam and propofol

Dipanjan Bagchi  1 , Mohan Chandra Mandal, Sabyasachi Das, Sekhar Ranjan Basu, Susanta Sarkar, Jyotirmoy Das
Affiliations

Bispectral index score and observer's assessment of awareness/sedation score may manifest divergence during onset of sedation: Study with midazolam and propofol

Dipanjan Bagchi et al. Indian J Anaesth. 2013 Jul.

Abstract

Background: Correlation between the clinical and electroencephalogram-based monitoring has been documented sporadically during the onset of sedation. Propofol and midazolam have been studied individually using the observer's assessment of awareness/sedation (OAA/S) score and Bispectral index score (BIS). The present study was designed to compare the time to onset of sedation for propofol and midazolam using both BIS and OAA/S scores, and to find out any correlation.

Methods: A total of 46 patients (18-60 years, either sex, American Society of Anesthesiologists (ASA) I/II) posted for infraumbilical surgeries under spinal anaesthesia were randomly allocated to receive either injection propofol 1 mg/kg bolus followed by infusion 3 mg/kg/h (Group P, n=23) or injection midazolam 0.05 mg/kg bolus followed by infusion 0.06 mg/kg/h (Group M, n=23). Spinal anaesthesia was given with 2.5 ml to 3.0 ml of 0.5% bupivacaine heavy. When sensory block reached T6 level, sedation was initiated. The time to reach BIS score 70 and time to achieve OAA/S score 3 from the start of study drug were noted. OAA/S score at BIS score 70 was noted. Data from 43 patients were analyzed using SPSS 12 for Windows.

Results: Time to reach BIS score 70 using propofol was significantly lower than using the midazolam (P<0.05). Time to achieve OAA/S score 3 using propofol was comparable with midazolam (P=0.358).

Conclusion: A divergence exists between the time to reach BIS score 70 and time to achieve OAA/S score 3 using midazolam, compared with propofol, during the onset of sedation.

Keywords: Bispectral index score; midazolam; observer's assessment of awareness/sedation score; propofol; sedation.

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Conflict of interest statement

Conflict of Interest: None declared

Figures

Figure 1
Figure 1
Comparison between time to reach BIS 70 and time to achieve OAA/S score 3. Graphs A and B compare the time in total patient population in study groups P and M respectively. Graphs C and D compare the time in patients who were severely anxious in study group P and M. The time to reach BIS score 70 and time to reach OAA/S 3 show a big divergence in group M patient population in comparition to group P. Group P received inj. Propofol; group M received inj. Midazolam
Figure 2
Figure 2
Comparison of the MAP and HR in both the study groups. Both MAP and HR were comparable in both the groups. Group P received inj. Propofol; group M received inj. Midazolam
See this image and copyright information in PMC

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