Efficacy of adding midazolam to bupivacaine for transversus abdominis plane block on postoperative analgesia after hysterectomy: A randomized controlled study

Abstract

Background and Aim:Different adjuncts have been utilized to promote the quality and prolong the duration of local anesthetics for a variety of regional block techniques. This study aimed to assess the effects of midazolam coadministered with bupivacaine in transversus abdominis plane (TAP) block on the 24-h morphine consumption, the postoperative analgesia duration and adverse effects.Settings and Design:A prospective, randomized, controlled double-blind trial that was carried out at a university hospital.Patients and Methods:Eighty-two females subjected to open total abdominal hysterectomy under general anesthesia were involved in this trial. Participants were allocated randomly to either of two groups (41 each). Control group: received TAP block with 20 mL of 0.25% bupivacaine or midazolam group: received TAP block using the same volume of bupivacaine plus 50 μg/kg midazolam/side. Postoperative cumulative 24-h morphine consumption, analgesia duration, pain score, sedation score, and adverse events were recorded.Statistical Analysis:Student's t-test, Mann–Whitney U-test, and Chi-square test were used.Results:Patients in the midazolam group had a lower cumulative 24-h morphine consumption [median doses (interquartile range): 15 (10–19.50) mg compared to 25 (17.50–37) mg, P < 0.001], lower postoperative pain score at rest at the 4th, 6th, and 12th h (P = 0.01, 0.02, and 0.02, respectively) and on movement at 2, 4, 6, and 12 h (P < 0.001), longer time till the first postoperative demand for rescue analgesia (430.11 ± 63.02 min) compared to 327.78 ± 61.99 min (P < 0.001), and less sedation, nausea and/or vomiting, and pruritus.Conclusions:Adding midazolam as a bupivacaine adjuvant for TAP block reduces the 24-h morphine consumption, extends the postoperative analgesia duration, and decreases the incidence of adverse effects following abdominal hysterectomy.

Comparative study of dexmedetomidine versus fentanyl as adjuvants to bupivacaine in ultrasound-guided transversus abdominis plane block in patients undergoing radical cystectomy: a prospective randomised study

“…Sedation scores were evaluated using a sedation scale (0 = awake, 1 = drowsy, 2 = asleep but arousable, 3 = deeply asleep). Patients were considered sedated, if they had a sedation score of > 0 at any time, during the first 24 h after surgery [ 19 ]. Patient satisfaction (area of satisfaction was pain relief) was also assessed in the form of 1 = poor, 2 = moderate, 3 = good, and 4 = perfect [ 20 ].…”

Adjuvant Drugs for Peripheral Nerve Blocks: The Role of Alpha-2 Agonists, Dexamethasone, Midazolam, and Non-steroidal Anti-inflammatory Drugs

“…A 2019 prospective randomized control trial by El Kenany and colleagues of this purpose reported a reduction in 24h morphine use and prolongation of postoperative analgesia (47). They assuaged the concern of neurotoxicity through the use of the established dosage of 50 µg/kg of midazolam (but with 20 mL of 0.25% bupivacaine) that has previously been proven to be safe (47). In their 2021 review, Desai et al describe the results for perineural effectiveness of midazolam to be conflicting due to unclear evidence about its benefits over systemic administration (52).…”

“…The data for the use of midazolam as an adjunct to local anesthetics in peripheral nerve blocks are limited in the field's current literature landscape (45). Midazolam could be a promising adjuvant owing to its ability to maintain the patient's hemodynamics (unchanged blood pressure and heart rate), relatively low costs, rapid action onset, and metabolic clearance that is better than other benzodiazepines that could warrant its further characterization (46,47).…”

“…Besides in brachial plexus blocks, midazolam has also lately been explored as an adjuvant to bupivacaine for a TAP block. A 2019 prospective randomized control trial by El Kenany and colleagues of this purpose reported a reduction in 24h morphine use and prolongation of postoperative analgesia (47). They assuaged the concern of neurotoxicity through the use of the established dosage of 50 µg/kg of midazolam (but with 20 mL of 0.25% bupivacaine) that has previously been proven to be safe (47).…”

“…The greatest concern about midazolam adjuvant use in PNB is its potential neurotoxicity (47). Multiple animal studies show intrathecal midazolam administration to be neurotoxic and midazolam's ability to significantly worsen neuronal cytotoxicity when combined with LA (36,45).…”