Analgesic efficacy of dexamethasone versus dexmedetomidine as an adjuvant to ropivacaine in ultrasound-guided transversus abdominis plane block for post-operative pain relief in caesarean section: A prospective randomised controlled study

Transversus Abdominis Plane Block Following Cesarean Section: A Prospective Randomized Controlled Study Comparing the Effects on Pain Levels of Bupivacaine, Bupivacaine + Dexmedetomidine, and Bupivacaine + Dexamethasone

Background: The transversus abdominis plane (TAP) block is providing effective postoperative analgesia in patients undergoing cesarean section (CS). This study aims to evaluate and compare the effects on pain levels of bupivacaine alone versus bupivacaine combined with dexmedetomidine and bupivacaine combined with dexamethasone in ultrasound-guided TAP block for postoperative pain after CS. Material and Method: In this randomized controlled trial, 120 patients with American Society of Anesthesiologists (ASA) physical status I and II scheduled for elective cesarean section under spinal anesthesia were randomly divided into three groups. At the end of the surgery, an ultrasound-guided TAP block was performed on all patients: bupivacaine 0.5% (Group B), bupivacaine 0.5% + dexmedetomidine (1 µg/kg) (Group BD), and bupivacaine 0.5% + dexamethasone (4 mg) (Group BDx). Postoperatively, all patients were evaluated at 0, 1, 4, 8, 16, and 24 h for visual analog scores VASs, tramadol consumption, complications, and patient satisfaction. A p value of < 0.05 is statistically significant. Results: At 0 h, VASs in the sitting and supine positions were significantly higher in the BDx group (0.85 ± 1.61 and 0.85 ± 1.36, respectively) compared to the B group (0.05 ± 0.32 in both positions) and the BD group (0.15 ± 0.48 in both positions) (p = 0.005 and p = 0.001, respectively). At the 24th hour, VASs in the sitting and supine positions were significantly lower in the BDx group (1.7 ± 1.2 and 1.43 ± 1.05) compared to the B group (2.3 ± 0.68 and 2.2 ± 0.72) and the BD group (2.57 ± 1.01 and 2.28 ± 0.78) (p = 0.005 and p = 0.001, respectively). At 0 h, the tramadol requirement was highest in the BDx group at 12.5%, while it was not required in the B and BD groups (p = 0.005). At 0 h, the rate of nausea and vomiting was highest in the BDx group at 17.5%, compared to 2.5% in the BD group and 0% in the B group (p = 0.003). Patient satisfaction scores were higher in the dexamethasone group compared to the other groups. This was significant between Group B and Group BDx (p = 0.009 < 0.05). Conclusions: Adding dexmedetomidine or dexamethasone to bupivacaine in ultrasound-guided TAP blocks reduces postoperative pain and increases patient satisfaction after cesarean sections. Dexamethasone, due to its delayed onset but extended duration, achieves lower pain scores and higher satisfaction. Further research is necessary to confirm these findings.

Comparative Study of Ropivacaine and Ropivacaine With Dexmedetomidine in Transversus Abdominis Plane (TAP) Block for Post-operative Analgesia in Patients Undergoing Cesarean Sections

Background Adequate post-operative analgesia in the obstetric patient is necessary to facilitate breastfeeding and the care of the newborn. Considering the limitations of intravenous analgesic options such as non-steroidal anti-inflammatory drugs (NSAIDs) and opioids, other alternatives have been tried for offering better analgesia with fewer potential side effects. Transversus abdominis plane (TAP) block is one such option that has been tried with various local anesthetic drugs, either alone or in combination with other adjuvants. The addition of dexmedetomidine to bupivacaine in TAP block has been shown to prolong the duration of post-operative analgesia when compared to local anesthetic alone. This study was conducted to determine the efficacy of dexmedetomidine, as an adjuvant to ropivacaine, when administered in TAP block in patients undergoing cesarean section. Methodology The study was a prospective, randomized, parallel assignment, triple-blinded controlled trial. Hundred patients posted for elective lower segment cesarean section, fulfilling the inclusion criteria, were randomly divided into two equal groups, group R and group RD, comprising 50 patients each. Patients in group R were administered bilateral TAP block by landmark technique using ropivacaine alone, whereas patients in group RD were administered TAP block with dexmedetomidine 1 micrograms/kg, in addition to a similar dose of ropivacaine. Mean arterial pressure (MAP), heart rate (HR), visual analog scale (VAS)-R (pain score on VAS scale at rest), VAS-C (pain score on VAS scale on coughing), nausea and vomiting, and Ramsay sedation score were recorded on admission to post-operative care unit (PACU), and at first, fourth, eighth, 12th, 18th, and 24th hours post-operatively. Rescue analgesia was provided with intravenous morphine. Short Assessment of Patient Satisfaction Score (SAPS) was noted on a five-point scale after 24 hours based on patient satisfaction regarding the quality of post-operative analgesia. Results While there was no significant difference between groups R and RD with respect to VAS-C and VAS-R immediately after shifting and at the first, fourth, and eighth hours, a significant difference was observed at the 12th and 18th hours post-operatively. After 24 hours, no significant difference was observed between groups R and RD with respect to VAS-C and VAS-R. While 50% of patients needed rescue analgesia in group R, only 28% of patients needed rescue analgesia in group RD. There was significantly better patient satisfaction measured by the Short Assessment of Patient Satisfaction Score (SAPS) with respect to the quality of analgesia in patients in group RD as compared to those in group R. Conclusions The addition of dexmedetomidine to ropivacaine increased the duration of post-operative analgesia up to 18 hours post-operatively in cases of elective lower segment cesarean section. Also, the quality of post-operative analgesia is better in such patients, as shown by a significant difference in patient satisfaction scores between the two groups.

Dexmedetomidine vs Dexamethasone as an Adjuvant to Levobupivacaine in Ultrasound-Guided Transversus Abdominis Plane Block for Postoperative Analgesia in Patients Undergoing Total Abdominal Hysterectomies

Background

In the postoperative period, open total abdominal hysterectomy (TAH) surgeries induce considerable pain. Multimodal strategies are being used to alleviate pain.

Objectives

This study aimed to examine the efficacy and safety of dexamethasone and dexmedetomidine as an adjuvant to levobupivacaine in ultrasound-guided transversus abdominis plane (TAP) blocks for postoperative pain in TAH patients.

Methods

A total of 72 patients with ASA grade I and grade II were randomly and equally assigned to two groups. After the completion of surgery with a subarachnoid block (SAB), patients in group 1 received a mixture of 20 mL of 0.25% levobupivacaine and 4 mg of dexamethasone on each side of the TAP block. Patients in group 2 received a mixture of 20 mL of 0.25% levobupivacaine and dexmedetomidine, with a total dose of 1 µg/kg body weight evenly distributed bilaterally in the TAP block. Patients were evaluated for pain using the Visual Analog Scale (VAS), total tramadol consumption as rescue analgesia, time to first rescue analgesia, any adverse effects, and patient satisfaction.

Results

When comparing VAS scores for pain assessment, we observed that the mean VAS score was initially comparable between the two groups for the first hour. However, at 6, 9, and 12 h, VAS scores were significantly lower in group 2. The mean total tramadol consumption was higher in group 1 than in group 2 (213.33 ± 44.08 vs 161.11 ± 37.93 mg, P-value 0.027). The time to the first rescue analgesia after the TAP block in the postoperative period was significantly longer in group 2 (47.5 ± 62.76 vs 77.22 ± 56.14 min, P-value 0.002). No significant side effects were noted, and a greater proportion of patients in group 2 expressed satisfaction with their overall pain treatment.

Conclusions

The addition of dexmedetomidine to levobupivacaine is superior to the addition of dexamethasone, as it prolongs the duration of the block in the dexmedetomidine group. However, the use of dexamethasone as an adjuvant is a good alternative option, particularly due to its lower cost and reduced incidence of adverse effects such as postoperative nausea and vomiting.

Effect of transversus abdominis plane block combined with low-dose dexmedetomidine on elderly patients undergoing laparoscopic colectomy

Introduction

Colon cancer is a common malignancy, for which surgery is currently the preferred therapy.

Aim

To assess the effect of transversus abdominis plane block (TAPB) combined with low-dose dexmedetomidine on elderly patients undergoing laparoscopic colectomy.

Material and methods

Sixty-two elderly patients undergoing laparoscopic colectomy between March 2021 and March 2022 were randomly selected and equally divided into Group A (low-dose dexmedetomidine) and Group B (TAPB + low-dose dexmedetomidine) by the randomized double-blind method. The treatment outcomes were compared.

Results

The resting and active Visual Analogue Scale and Pittsburgh Sleep Quality Index scores were lower in Group B than those in Group A at 6 h, 1 day, 2 days and 3 days after operation (p < 0.05). The two groups had no significant differences in the levels of cluster of differentiation 4+ (CD4+), CD8+ and free Cor, CD4+/CD8+ ratio and NK cell level before anesthesia (p > 0.05). At 24 h after the operation, the level of CD4+, CD4+/CD8+ ratio and NK cell level were higher in Group B than those in Group A, and the levels of CD8+ and free Cor were lower in Group B (p < 0.05). Group B had higher partial pressure of oxygen ((45.52 ±11.14) mm Hg) and pH (7.42 ±0.06) (p < 0.05) and lower partial pressure of carbon dioxide ((4.05 ±0.32) mm Hg) than those of Group A (p < 0.05).

Conclusions

TAPB combined with low-dose dexmedetomidine can exert better anesthetic, analgesic and sedative effects, and ameliorate stress responses.

Dexmedetomidine as an Adjuvant in Peripheral Nerve Block

Peripheral nerve block technology is important to balanced anesthesia technology. It can effectively reduce opioid usage. It is the key to enhance clinical rehabilitation as an important part of the multimodal analgesia scheme. The emergence of ultrasound technology has accelerated peripheral nerve block technology development. It can directly observe the nerve shape, surrounding tissue, and diffusion path of drugs. It can also reduce the dosage of local anesthetics by improving positioning accuracy while enhancing the block's efficacy. Dexmedetomidine is a highly selective drug α₂-adrenergic receptor agonist. Dexmedetomidine has the characteristics of sedation, analgesia, anti-anxiety, inhibition of sympathetic activity, mild respiratory inhibition, and stable hemodynamics. Numerous studies have revealed that dexmedetomidine in peripheral nerve blocks can shorten the onset time of anesthesia and prolong the time of sensory and motor nerve blocks. Although dexmedetomidine was approved by the European Drug Administration for sedation and analgesia in 2017, it has not yet been approved by the US Food and Drug Administration (FDA). It is used as a non-label drug as an adjuvant. Therefore, the risk-benefit ratio must be evaluated when using these drugs as adjuvants. This review explains the pharmacology and mechanism of dexmedetomidine, the effect of dexmedetomidine on various peripheral nerve block as an adjuvant, and compare it with other types of adjuvants. We summarized and reviewed the application progress of dexmedetomidine as an adjuvant in nerve block and look forward to its future research direction.