A Comparative Controlled Study of Preoperative Skin Infiltration with Bupivacaine-Dexmedetomidine versus Bupivacaine-Magnesium for Pain Control Analgesia in Para Umbilical Hernia regarding Their Perioperative Analgesic Effect

Abstract Background Postoperative pain and opioid-related adverse drug events are still among the principal factors affecting the rapid recovery and discharge of patients undergoing surgery. Wound pain at rest and on movement is one of the main sources of postoperative pain. In addition, skin traction stimulation, which can be caused by respiratory movement and the daily activities of patients after surgery, further aggravates the severity of wound pain, resulting in restlessness and insomnia and even inducing serious symptoms such as wound tear and infection. The analgesic regimen needs to meet the goals of providing safe, effective analgesia, with minimal side effects for the patient, together with inhibition of trauma –induced nociceptive impulses. The technique of wound infiltration analgesia has been shown to play an active role in relieving postoperative pain and reducing opioid consumption. Aim of the Work Comparing the effectiveness of pre-incision skin infiltration with bupivacaine- dexmedetomidine mixture versus bupivacaine-magnesium mixture for elective para umbilical hernia repair. Patients and Methods A Prospective randomized, double blinded controlled study was conducted in Ain Shams university hospital on 75 adult patients undergoing para umbilical hernia or infra umbilical incisional hernia repair. They will be randomly divided into three groups. Method of randomization using computer generated number list using opaque sealed envelopes. Patients will be enrolled in group B for bupivacaine alone, group D for bupivacaine-dexmedetomidine and group M for bupivacaine-magnesium. Results This study demonstrated that the addition of dexmedetomidine to wound infiltration with local anesthetics improves postoperative pain and reduces the need for analgesics which can be explained by different mechanisms: inhibition of pain conduction in C-fibers, decreased in the production of inflammatory cytokines, the vasoconstrictive effect of 2 on vascular smooth muscle prolongs the time of analgesia, inhibition of tetrodotoxin-sensitive Na+ channels, and the absorption of dexmedetomidine to systemic circulation resulting in supraspinal analgesia. Conclusion Dexmedetomidine is found to be an effective adjuvant to bupivacaine for local wound infiltration analgesia in terms of effective analgesic duration, need for rescue analgesic and better pain scores in the immediate postoperative period, and provides better sedation than bupivacaine–magnesium sulfate mixture or bupivacaine alone in patients undergoing surgeries for hernia repair.