Comparison of Three Different Doses of Dexmedetomidine Added to Bupivacaine in Ultrasound-Guided Transversus Abdominis Plane Block; A Randomized Clinical Trial

Background: Adding dexmedetomidine to bupivacaine has been shown to prolong the analgesic effects of the transversus abdominis plane (TAP) block. However, the optimal dose of this adjuvant drug is unclear. Objectives: Identifying optimal doses of dexmedetomidine added to bupivacaine in the TAP block. Methods: In this randomized controlled trial, 86 patients candidate for elective open inguinal herniorrhaphy under spinal anesthesia were divided randomly into three groups; low (L), medium (M), and high (H) dose of dexmedetomidine, that finally 80 cases ended the study and were analyzed. At the end of the surgery, the patients underwent ultrasound-guided TAP block. In all patients of the three groups, the analgesic base of the block was 20 mL bupivacaine 0.125% that was supplemented with 0.5, 1, or 1.5 µ/kg of dexmedetomidine in groups L, M, and H, respectively. Results: The maximum duration of the block was 4 hours in group L and 8 hours in groups M and H. None of the patients needed to receive analgesic at 0, 2, and 24 hours after the block. The dose of analgesic required in the first 8 hours of the block in groups M and H was less than in group L (P < 0.02). Patients in groups H and M were more satisfied with the block (P < 0.01) and experienced less pain compared with group L (P < 0.01). Drowsiness and sedation were observed in patients up to 4 hours after the TAP block, which was dependent on the dexmedetomidine dose (P < 0.01). Conclusions: Based on our results, the optimal dose of supplemental dexmedetomidine could be 1 µ/kg in the TAP block.

Ilioinguinal/Iliohypogastric versus quadratus lumborum nerve blockade for elective open inguinal herniorrhaphy: a prospective, randomized, double-blinded, equivalency trial

BackgroundOpen inguinal herniorrhaphy (OIH) is a commonly performed surgical procedure with expected postoperative pain. Historically, an option for regional analgesia has been an ilioinguinal and iliohypogastric nerve block (IINB). More recently, the transmuscular quadratus lumborum block (QLB) has been used as an analgesic technique for a variety of abdominal and truncal surgical procedures. Given our own institutional experiences with the performance of QLB combined with the body of literature supporting the proximal blockade of the ilioinguinal and iliohypogastric nerves via this approach, we compared the analgesia provided by an IINB to a QLB. We hypothesized that the two blocks would provide equivalent analgesia, as defined by a difference of less than±2 points on the pain scale (0–10 numeric rating scale (NRS)), for patients undergoing OIH.MethodsSixty patients scheduled for elective outpatient OIH under general anesthesia were randomized to preoperatively receive either an IINB or a transmuscular QLB with 0.25% bupivacaine/epinephrine/clonidine for postoperative analgesia. The primary endpoint was movement NRS pain scores at 8 hours. Secondary outcomes included resting NRS pain scores at 8 and 24 hours, movement NRS pain scores at 24 hours, incidence of opioid related side effects (nausea, vomiting, pruritus), time-to-first oral opioid analgesic, and total opioid consumption at 24 hours.ResultsFifty-nine patients were analyzed per an intention-to-treat approach (one patient was excluded because the surgical procedure was canceled). Movement pain scores at 8 hours were equivalent (IINB 5.10±3.02 vs QLB 5.03±3.01 (mean NRS±SD); two one-sided test mean difference (90% CI), 0.07 (−1.24 to 1.38), p ≤0.01). There were no differences between groups for any of the secondary endpoints.ConclusionAn IINB and a transmuscular QLB are equivalent with regards to their ability to provide postoperative analgesia after OIH.