Prevention of hypotension and prolongation of postoperative analgesia in emergency cesarean sections: A randomized study with intrathecal clonidine

BACKGROUND AND CONTEXT: Different adjuvants been tried out for neuraxial anesthesia in emergency caesarean section so that the dose of the local anesthetic can be reduced and hypotension thereby prevented. AIMS AND OBJECTIVES: The present study was carried out in patients presenting for emergency lower segment caesarean section (LSCS) to establish the dose of intrathecal clonidine that would allow reduction of the dose of local anesthetic (thereby reducing the incidence and magnitude of hypotension) while at the same time providing clinically relevant prolongation of spinal anesthesia without significant side effects. MATERIALS AND METHODS: This randomized clinical study was carried out in our institution among 100 pregnant females who underwent emergency caesarean section. The participants were divided randomly into four groups: A, B, C, and D, each comprising 25 parturients. Subarachnoid block was performed using a 26G Quincke needle, with 12 mg of hyperbaric bupivacaine (LA) in group A, 9 mg of LA + 30 μg of clonidine in group B, LA + 37.5 μg of clonidine in group C, and LA + 45 μg of clonidine in group D. The solution was uniformly made up to 2.2 mL with normal saline in all the groups. Onset of analgesia at T(10) level, sensory and motor blockade levels, maternal heart rate and blood pressure, neonatal Apgar scores, postoperative block characteristics, and adverse events were looked for and recorded. Statistical analysis was carried out with SPSS(®) version 10.0 for Windows(®), using the ANOVA test with post hoc significance, the Chi-square test, and the Mann-Whitney U test. P<.05 was considered significant and P<.0001 as highly significant. RESULTS: One hundred patients were enrolled for this study. The four groups were comparable with regard to demographic data and neonatal Apgar scores. Onset and establishment of sensory and motor analgesia was significantly shorter in groups C and D, while hypotension (and the use of vasopressors) was significantly higher in groups A and D. Perioperative shivering, nausea, and vomiting were significantly higher in groups A and D, while incidence of dry mouth was significantly higher in group D. CONCLUSIONS: The addition of 45 μg, 37.5 μg, and 30 μg of clonidine to hyperbaric bupivacaine results in more prolonged complete and effective analgesia, allowing reduction of up to 18% of the total dose of hyperbaric bupivacaine. From the results of this study, 37.5 μg of clonidine seems to be the optimal dose.