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Abstract CAUDAL analgesia, a relatively simple technique with a predictable level of blockade, provides excellent postoperative analgesia and reduced general anesthetic requirements. Ease of performance and reliability makes caudal analgesia the most common of all blocks performed in children. It is widely used for various surgical procedures, such as lower abdominal, urological and lower limb surgery. In order to decrease intra and postoperative analgesic requirements after caudal blockade, various additives such as morphine, fentanyl, ketamine, adrenaline, clonidine and magnesium can be added with local anesthetics. Bupivacaine has been in clinical use for more than 30 years and is available commercially as a racemic mixture containing equal proportions of the S (-) and R (+) isomers. It is widely used for caudal epidural analgesia in children because of its long duration of action and beneficial ratio of sensory to motor blocks. Magnesium is an antagonist of the N-methyl-D-aspartate (NMDA) receptor ion channel, and this may explain part of its analgesic activity and it has been called “nature’s physiological calcium channel blocker. Fentanyl is anopioid analgesic with potency eighty times that of morphine; fentanyl is extensively used for anaesthesia and analgesia in the operating room and intensive care unit. It is frequently given intrathecally as a part of spinal ana¬esthesia or, and also used as a sedative. The present study included 60 patients of class I and class II of the ASA classification, 2 to 10 years old, who were scheduled for either lower abdominal or penoscrotal surgical procedures. All patients received general anaesthesia using halothane and oxygen. No sedatives or analgesic drugs were used prior to surgery. This study was designed to evaluate and investigate the efficacy of caudal bupivacaine alone compared to its mixture with magnesium sulphate in a group and its mixture with fentanyl in another group. Therefore, patients were divided into three groups; • group I: 20 patients received l ml/kg of plain bupivacaine 0.25%. • group II: 20 patients received 1ml/kg plain bupivacaine 0.25% plus magnesium sulphate 50 mg (0.5ml). • group III: 20 patients received 1ml/kg plain bupivacaine 0.25% with fentanyl (1µg/kg). Those groups were comparable as regards age, sex and duration of surgical procedures. All patientsofthe 3 groups were monitored by; heart rate (HR) , non-invasive systolic arterial blood pressure (MAP) and arterial oxygen saturation (SO2). All these parameters were recorded just before and after caudal injection, every 5 minutes till the end of surgery, then every 15 minutes for the first hour postoperatively and then after 2,3,4, 6 and 12 hours post-operatively. Pain was assessed using the pediatric objective pain score (POPS) and Children’s Hospital of Eastern Ontoria Pain Scale (CHEOPS) and was recorded at 15 minutes, 1,2, 3,4,6 and 12 hours. It is clear from this study that addition of magnesium sulphate 0.5 ml (50 mg) to bupivacaine 1ml/kg 0.25% has no more analgesic effect than bupivacaine 1ml/kg 0.25% alone or bupivacaine with fentanyl but it has a rapid onset of action of its analgesic effect intraoperatively and this is clear by early stabilization of hemodynamics intraoperatively. Also, addition of fentanyl 1µg/kg to bupivacaine 1ml/kg 0.25% has significantly prolonged the postoperative analgesic effect in comparison to the addition of magnesium sulphate to bupivacaine or bupivacaine alone and this was obvious by the persistent low POP and CHEOPS scores and subsequent deceased needs of postoperative rescue analgesia till the 12th hour postoperatively. No side effects were reported as prolonged sedation, respiratory distress, motor weakness or urine retention. |