Aim: The aim of this study is to evaluate the effect of the low doses of ketamine and midazolam with bupivacaine intrathecally in terms of duration of analgesia and haemodynamic parameters.

Materials and Methods: This prospective randomized double blind study conducted in patients posted for Infra umbilical surgeries. Patients with physical status ASA I and ASA II with Infra umbilical surgeries like herniorrhaphy, varicose vein surgery, orthopaedic surgeries with less than 3 hr duration were taken up for the study.

Results: All demographic details are not significant. With addition of midazolam and ketamine the mean onset of sensory block is quicker compared to other two groups. with addition of midazolam and ketamine the mean onset of motor block is quicker compared to other two groups. With addition of Midazolam and ketamine the maximum sensory level and reached in higher compared to other two groups. With addition of midazolam and ketamine the duration of sensory block and motor block is prolonged compared to other two groups. With addition of ketamine and Midazolam the mean duration of  pain free interval is prolonged and rescue analgesics required are less compared to other two groups. In all three groups the mean systolic blood pressure was comparable and they are not statistically significant. The Vasopressors required in Group A and C were compared and they are not statistically significant. In Group B and Group C the sedation score was higher compared to Group A.

Conclusion: Low doses of preservative free ketamine (0.1mg/kg) and midazolam (0.02mg/kg) when added to bupivacaine intrathecally provides prolonged post operative analgesia without any significant side effects.