A COMPARATIVE STUDY OF EFFECT OF DEXMEDETOMIDINE AND DEXAMETHASONE AS AN ADJUVANT TO 0.2% ROPIVACAINE FOR ULTRASOUND GUIDED TRANSVERSUS ABDOMINIS PLANE BLOCK FOR INFRAUMBILICAL SURGERIES

Background: The relief of pain and suffering is, and always has been, one of the primary concerns of mankind and one of the prime factors that has influenced the course of history of medicine. Transversus abdominis plane (TAP) block is a regional anaesthetic technique which blocks the abdominal neural afferents by introducing local anaesthetic into the neuro-fascial plane between the internal oblique and the transversus abdominis muscle. Aim: To compare the efficacy of Dexmedetomidine and dexamethasone as an adjuvant to 0.2%ropivacaine in ultrasound guided transverses abdominis plane block in infra umbilical surgeries in terms of, 1. Time to initial postoperative pain. 2. Time to initial rescue analgesia. 3. Quality of block.. 4. Total postop analgesic consumption. 5. Patient satisfaction with regard to pain relief. 6. Post-operative nausea and vomiting. Materials And Methods: We included 80 patients of age between 18-60 years of American Society of Anesthesiologists status (ASA)I and II scheduled for elective infraumbilical surgeries in our study. We randomly allotted these patients into two groups namely Group A and Group B of each. Patients in Group APatients who received transversus abdominis plane block with - 18ml Ropivacaine 0.2%+ 2 ml Dexamethasone 8mg. Patients in Group B received transversus abdominis plane block with-18ml Ropivacaine 0.2%+ 2 ml Dexmedetomidine .This TAP block was given soon after the surgery is completed. The duration of block and regression of sensory block, time for rescue analgesia, degree of sedation, hemodynamic parameters, post operative analgesia and adverse effects were noted. Result: The two groups were comparable on the basis of duration of surgery, site of surgery, ASA and BMI. Heart rates and mean arterial pressure were compared and it was found to be significantly lower in group B compared to group A until initial 5 hours. In our study we found that the visual analogue score at rest and on coughing between groups A and B was statistically insignificant. However, the time to first rescue analgesia (330 mins vs 240 mins) and total analgsic consumption in the 24 hours period post operatively was significantly lesser for group A compared to group B. Ramsey sedation score was significantly higher in group B compared to group A until 8 hourspost operatively. Nausea and vomiting in 3 cases of group A , and 2 cases in group B. No other significant side effects were noted. Conclusion: USG-guided TAP block is an effective and safe adjunct for postoperative analgesia in infra umblical surgeries. Addition of dexamethasone as an adjuvant prolongs the duration and reduces post-operative analgesic requirement in patients significantly more than dexmedetomidine whereas dexamethasone provides better control of the heart rate and mean arterial pressure.背景：缓解疼痛与痛苦始终是人类的核心关切之一，亦是推动医学发展历程的关键因素之一。腹横肌平面（Transversus abdominis plane, TAP）阻滞作为一种区域麻醉技术，通过将局部麻醉药物注入腹内斜肌与腹横肌之间的神经筋膜平面，阻断腹部神经传入信号。 目的：本研究旨在比较超声引导下TAP阻滞中，以0.2%罗哌卡因为基础，分别添加右美托咪定与地塞米松作为佐剂的临床疗效，评估指标包括：1. 术后首次疼痛发作时间；2. 首次补救镇痛时间；3. 阻滞质量；4. 术后镇痛药物总消耗量；5. 患者对疼痛缓解效果的满意度；6. 术后恶心呕吐发生情况。 材料与方法：本研究纳入80例年龄18~60岁、美国麻醉医师协会（American Society of Anesthesiologists, ASA）分级I~II级、拟行择期脐下手术的患者。将所有患者随机分为A、B两组，每组各40例。A组患者接受18ml 0.2%罗哌卡因联合2ml 8mg地塞米松的TAP阻滞方案；B组患者接受18ml 0.2%罗哌卡因联合2ml右美托咪定的TAP阻滞方案。该阻滞操作于手术结束后即刻实施。本研究记录的指标包括：阻滞持续时间、感觉阻滞消退时间、补救镇痛时间、镇静程度、血流动力学参数、术后镇痛情况及不良反应。 结果：两组患者在手术时长、手术部位、ASA分级及BMI方面均具有可比性。对比心率与平均动脉压可见，术后最初5小时内，B组的上述指标均显著低于A组。本研究显示，两组患者静息及咳嗽时的视觉模拟评分（Visual Analogue Score, VAS）差异无统计学意义。然而，A组的首次补救镇痛时间（330min vs 240min）及术后24小时镇痛药物总消耗量均显著低于B组。术后8小时内，B组的Ramsey镇静评分显著高于A组。A组共出现3例恶心呕吐病例，B组为2例，未观察到其他显著不良反应。 结论：超声引导下TAP阻滞用于脐下手术术后镇痛是安全有效的辅助手段。相较于右美托咪定，添加地塞米松作为佐剂可显著延长阻滞持续时间并降低患者术后镇痛药物需求量，且地塞米松对心率与平均动脉压的控制效果更优。