Journal of Anesthesiology and Pain

Background and aims
The efficacy of adding midazolam to intrathecal bupivacaine has been widely documented. The aim of this study was to assess the effects of combination of intrathecal midazolam and lidocaine on postoperative pain.
Methods
In a randomized controlled trial that was performed in 2007 in a teaching hospital of Arak University of Medical Sciences, forty five male patients who were candidates for elective inguinal herniorrhaphy entered and randomly divided into three groups of Control (lidocaine 5% plus Normal saline), M0.5 (lidocaine 5% and midazolam 0.5mg) and M1 (lidocaine 5% and midazolam 1 mg) according to intrathecal solution injected for spinal anesthesia. Mean arterial blood pressure, heart rate, post-operative pain, narcotic requirements, and complications (nausea, vomiting, pruritis, headache, hypotension and bradycardia) were recorded.
Results
The severity of post-operative pain was lowest in M1 group in all postoperative measurements except at 2 hours after operation.There was significant difference in vomiting between three groups which had the highest frequency in M0.5 group. No severe hypotension was seen though, bradycardia occurred in one patient in M0.5 group which needed treatment.
Conclusions
Our findings suggest that administration of intrathecal midazolam (especially 1mg) together with lidocaine is effective in reducing post-operative pain in patients undergoing open inguinal herniorrhaphy and is not associated with adverse effect.