Midazolam vs. Meperidine plus Bupivacaine as spinal anaesthesia in woman undergoing caesarean surgery: clinical trial study. Habib Zakeri 1 , Mona Rajabi 1 , Mehrdad Badpa 2 , Mahshid Abdollahi 2 , Samira Salehi 2 , Ali Hosseinipour 1* 1 Noncommunicable Diseases Research Center, Fasa University of Medical Sciences, Fasa, Iran 2 Student Research Committee, Fasa University of Medical Sciences, Fasa, Iran Abstract Background: The rate of caesarean section has risen from less than 7% in 1970s to more than 25% in 2003. Objective: Due to the side effects of caesarean operation as well as the vital cares needed in this procedure, the raise in the ratio has expressed the technique as a matter of global concern. Methods: A total of 93 patients’ undergone caesarean sections under spinal anaesthesia with American Society of Anaesthesiologists Class 1 and 2 were included in the study. The patients were randomly divided into three groups of 31 persons. All 3 groups received 10 mg of 0.5% bupivacaine then 25 mg of meperidine was added for the second group and 2 mg of midazolam was used for the third group while the first group received placebo in addition to bupivacaine. RM-ANOVA, chi square, and ANOVA using Bonferroni correction method we used to compare the data. All analysis was done using SPSS 20. P- value less than 0.05 considered as the significant level. Results: For 10 (23.3%) subjects in the Midazolam group, 19 (61.3%) subjects in the meperidine group and 24 (77.4%) subjects in the placebo group were used anti-nausea medication. It indicates that the Midazolam group, used anti-nausea medication less than other groups (P=0.001). Immediately after spinal anaesthesia, the rate of pain was lower in the meperidine group (mean of pain score: 0.19) and it started later than other groups until 2 hours after anaesthesia. The frequency of pain was low until 3 hours after anaesthesia. Conclusion: This investigation demonstrates that meperidine for its longer duration of analgesia is better than midazolam while with regard to having fewer side effects, the reverse is preferable. So, injecting sufficient dosage of midazolam along with bupivacaine could be a good choice for additive drug. Keywords: Midazolam, Meperidine, Bupivacaine, Spinal anaesthesia, Caesarean. Accepted on November 12, 2016 Introduction One of the most common surgical procedures in the world is caesarean delivery and its rate has dramatically increased in recent years. The rate of caesarean section has risen from less than 7% in 1970s to more than 25% in 2003 [1]. Due to the side effects of caesarean operation as well as the vital cares needed in this procedure, the raise in the ratio has expressed the technique as a matter of global concern [2]. The most frequent complaint by those who have undergone this operation is pain. Post-caesarean pain is a common cause of acute pain in the obstetrics [3], which can lead to many postoperative complications; for example, an unpleasant feeling increasing during hospitalization, the time needed to get out of bed, immobility and the reduced patient’s desire to move and rise up. In addition, the complications caused by immobility such as atelectasia, deep vein thrombosis, and constipation are mentionable [4]. Therefore, pain management is an important component of postoperative care in which the anaesthesiologist has a considerable role to choose an appropriate technique [5]. In the past two decades, regional anaesthesia has become a preferred method instead of general anaesthesia [6]. The simplicity of this technique along with its reliability, minimal foetal exposure to drugs, patients’ awareness and minimization of the hazards of aspiration are the advantages of spinal anaesthesia rather than general anaesthesia [7]. Bupivacaine is the most common drug used in the spinal anaesthesia but its high dosage is associated with the increased incidence of hypotension [8]. Intraoperative hypotension can cause many detrimental effects on both mother and neonate including nausea, vomiting, dizziness, decreased uteroplacental blood ISSN 0970-938X www.biomedres.info Biomedical Research 2017; 28 (6): 2768-2772 2768 Biomed Res- India 2017 Volume 28 Issue 6