Sedation with 1 mg Intravenous Midazolam in Subarachnoid Block with Bupivacaine and Fentanyl for Lower Limb Surgeries Causes Clinical Sedation without Hemodynamic Compromise: A Randomized Controlled Trial

Abstract

cardiac arrest. Thus frequently IV sedation in SAB is frequently discouraged.
Hypothesis of the present study was that SAB with bupivacaine and fentanyl would correspond to a BIS < 90,
level of clinical sedation and IV midazolam 1 mg in such patients may cause hemodynamic compromise.
Primary objective was to compare BIS post SAB with and without IV midazolam. Secondary objective was to
compare hemodynamic parameters.
Methods: 60 patients of age 20-60 years, ASA 1 or 2, undergoing lower limb surgeries were given SAB with
0.5% hyperbaric bupivacaine 2 mL (10 mg) and fentanyl 0.5 mL (25mcg). Thereafter Group A (n=30) was given
SAB with 1ml IV saline and Group B (n=30) was given SAB with IV 1mg midazolam.
Parameters were recorded at baseline, then every 15 minutes till 90 minutes.
Results: In Group B, BIS < 90 but not < 80 was noted from 30 minutes to at least 90 minutes. In Group A, BIS <
90 was noted from 45 minutes to 60 minutes and was > 90 at all other time frames. Mean BIS was significantly
more in Group A compared to Group B (90.41 +/- 4.05 v/s 86.58 +/- 3.50 respectively) (P< 0.001). Hemodynamic
parameters of heart rate, non-invasive blood pressure, oxygen saturation and respiratory rate were comparable
between both groups (p value >0.05).
Conclusion: SAB does not result in adequate intra operative patient sedation. IV midazolam 1 mg causes BIS
<90 from 30 minutes till at least 90 minutes without hemodynamic compromise.