Postoperative analgesic effect of hyaluronidase versus dexamethasone as additives to bupivacaine in transversus abdominis plane block for inguinal hernia repair: prospective, randomized, and double-blinded controlled study

Background Inguinal hernia repair is associated with severe postoperative pain. Transversus abdominus plain block has been proved to provide effective analgesia for somatic lower abdominal pain. Several adjuvants have been added to local anesthetic to improve the quality of analgesia. This study compares the additive effect of hyaluronidase versus dexamethasone to improve the quality of analgesia of transversus abdominus plain block for inguinal hernia repair. Patients and methods This prospective, randomized, controlled, and double-blind study was carried out in Sohag University Hospital between November 2020 and February 2021. Seventy-five participants scheduled for inguinal hernia repair were included and randomly assigned into control, hyaluronidase, and dexamethasone groups. Exclusion criteria were neurological, psychiatric, neuromuscular, cardiovascular, pulmonary, renal, hepatic disease, alcoholism or drug abuse, pregnancy or lactating women, and patients receiving adrenoceptor agonist or antagonist therapy or chronic analgesic therapy, patients with morbid obesity, coagulopathy, and known allergy to study medications, and sepsis surgical scar at the site to be operated upon and those who refuse. We targeted from this study to assess time to first analgesia, consumption of morphine, and visual analog scale at rest and during physical activity. Also, we targeted to assess heart rate, noninvasive blood pressure, SpO2%, and adverse effects (nausea and vomiting, respiratory depression). Results Our study showed comparable analgesic efficacy for hyaluronidase versus dexamethasone with longer time to the first request of analgesia, less morphine consumption, and less side effects compared with these two groups to the control group. Conclusion Adding hyaluronidase or dexamethasone to bupivacaine not only prolonged the duration of analgesia and decreased the consumption of opioids but also decreased the incidence of adverse effects.