[Efficiency of bupivacaine and association with dexmedetomidine in transversus abdominis plane block ultrasound guided in postoperative pain of abdominal surgery]

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

Background

Transversus abdominis plane (TAP) block is beneficial for pain management after conducting abdominal surgery.

Objective

To compare the outcomes of dexmedetomidine and fentanyl, as adjuvants to bupivacaine, for ultrasound-guided TAP block analgesia among patients undergoing radical cystectomy for postoperative pain management.

Methods

This prospective, randomised, comparative study included a total of 60 patients, who underwent radical cystectomy. Participants were randomly divided into three categories with 20 subjects each; group B had patients who received a single shot US-guided TAP block on each side with 20 ml of 0.25% bupivacaine + 2 ml normal saline; group BF had patients who received a single shot US-guided TAP block on each side with 20 ml of 0.25% bupivacaine + 1 µg/kg fentanyl dissolved in 2 ml normal saline and group BD had patients who received a single shot US-guided TAP block on each side with 20 ml of 0.25% bupivacaine + 1 µg/kg dexmedetomidine dissolved in 2 ml normal saline.The researchers recorded the time taken for first rescue analgesia, total analgesic dose in the first 24 h after surgery, patient satisfaction, sedation score, and postoperative complications.

Results

The time taken for first rescue analgesia was significantly lengthier in group (BD) (8.90 ± 2.47) than (BF) (6.50 ± 1.43) and (B) (4.40 ± 1.05) groups. The total nalbuphine consumption, during the first 24 h, was significantly lower in (BD) (0.15 ± 0.00) group compared to (BF) (0.20 ± 0.07) and (B) (0.24 ± 0.08) groups.

Conclusion

In comparison with fentanyl, as an adjuvant to bupivacaine, dexmedetomidine was found to be associated with prolonged postoperative analgesia, less postoperative pain scores and low opioid consumption.

Trial registration

This study was registered at Clinical Trials.gov on 23 March 2020 (registration number: NCT04318158).

Pharmacokinetics and Pharmacodynamics of Dexmedetomidine Administered as an Adjunct to Bupivacaine for Transversus Abdominis Plane Block in Patients Undergoing Lower Abdominal Cancer Surgery

Background

Despite the growing interest in dexmedetomidine as an adjunct to truncal blocks, little is known about the systemic absorption of dexmedetomidine after these blocks and its role in analgesia and in hemodynamics.

Objective

We investigated the pharmacokinetics and pharmacodynamics of dexmedetomidine as an adjunct to transversus abdominis plane (TAP) block in patients undergoing lower abdominal cancer surgery.

Methods

Twenty-four adult patients were randomized to receive a bilateral single-injection TAP block before surgery with 20 mL of bupivacaine 0.5% (TAP group, n = 12) or combined with 1 µg/kg dexmedetomidine (TAP-DEX group, n = 12) and diluted with saline to a volume of 40 mL (20 mL on each side). Plasma concentrations of dexmedetomidine and its pharmacokinetics were investigated using non-compartmental methods, postoperative analgesia, hemodynamics, and adverse events (nausea, vomiting, itching, hypotension, bradycardia, and respiratory depression).

Results

Dexmedetomidine was detected in the plasma of 11 patients in the TAP-DEX group. The mean dexmedetomidine peak plasma concentration (Cmax) was 0.158 ± 0.085 (range, 0.045-0.31) ng/mL. The median time to reach peak plasma concentration of dexmedetomidine (Tmax) was 15 (15-45) min. From 2 to 8 h postoperatively, visual analog pain scale (VAS) scores at rest and during movement were significantly lower in the TAP-DEX group. Analgesia time was (11.3 ± 3.12 vs 9.0 ± 4.69 h; P = 0.213) and postoperative morphine consumption was (7.4 ± 3.24 vs 11.5 ± 4.46 mg; P = 0.033) in TAP-DEX and TAP groups, respectively. Lower mean heart rate and mean blood pressure were recorded in the TAP-DEX group intraoperatively and 2 h postoperatively (P < 0.05). Except for mild nausea and vomiting, no adverse events were recorded in either group.

Conclusion

Systemic absorption of dexmedetomidine administered in a TAP block is common. Direct central effects on the locus coeruleus caused by this systemic absorption may play a role in the analgesia and hemodynamic effects produced by TAP-dexmedetomidine in addition to local mechanisms.

Trial Registration

ClinicalTrial.gov (identifier: NCT03328299).

Levobupivacaine versus levobupivacaine plus dexmedetomidine in transversus abdominis plane block in patients undergoing abdominal aortic surgery

Background:

Severe postoperative pain is a major dilemma for patients undergoing abdominal aortic surgery. Transversus abdominis plane (TAP) block has been described a successful pain management technique after major abdominal surgery. Dexmedetomidine was proved to enhance the analgesic action of local anesthetics.

Aim:

This study was aimed to assess the impact of adding dexmedetomidine to levobupivacaine during TAP block in patients undergoing abdominal aortic operations.

Patients and Methods:

We included 114 patients in this prospective trial, and they were enrolled into two groups; the L group received levobupivacaine only, and the LD group received levobupivacaine plus dexmedetomidine. The block was performed before anesthetic induction. Postoperative pain score was our main outcome.

Statistical Analysis:

The collected data were tabulated and analyzed through the SPSS software program IBM's Statistical Package for the Social Sciences (SPSS) statistics for Windows (version 25, 2017) (IBM Corporation, Armonk, NY, USA). The categorical data were expressed as numbers and percentages and then compared using the Chi-square test. The continuous data were expressed as mean and standard deviation if normally distributed, or median and range if abnormally distributed. The former data were compared through the one-way ANOVA, while the latter were compared through the Kruskal–Wallis test. Any P < 0.05 was considered statistically significant.

Results:

Group LD showed significantly earlier sensory blocks compared to the other group. Postoperative pain scores were comparable between the two groups for the initial 4 h following the surgery. Adjuvant dexmedetomidine was associated with better pain scores for the subsequent 12 h compared to Group L. The duration till the first analgesic request showed a significant increase in the LD group (13.3 vs. 11.09 h in Group L). In addition, the same group showed a significant decline in their opioid consumption after the operation (48.95 μg vs. 72.63 μg in the other group). Postoperative nausea and vomiting were significantly increased in Group L.

Conclusion:

Adjuvant dexmedetomidine has a significant beneficial impact on postoperative analgesic profile. Its use as an adjuvant to peripheral and neuraxial nerve blocks should be recommended in pain management practice.

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.

Ultrasound-guided transversus abdominis plane block for postoperative analgesia in laparoscopic cholecystectomy: A retrospective study

OBJECTIVE:

This study aimed to investigate the effects on postoperative pain of ketamine and dexmedetomidine addition to bupivacaine in a transversus abdominis plane (TAP) block in laparoscopic cholecystectomy.

METHODS:

A retrospective study was conducted patients who underwent ultrasound-guided TAP block in laparoscopic cholecystectomy. The patients were divided into three groups: Group BD (Bupivacaine+Dexmedetomidine), Group BK (Bupivacaine+Ketamine), and Group B (Bupivacaine). Our primary outcomes were pain scores with Visual Analogue Scale (VAS), postoperative first analgesic time and tramadol consumption in 24 hours postoperatively. Secondary outcomes were intraoperative hemodynamic changes, rescue analgesic requirement and side effects.

RESULTS:

The first analgesic administration time was significantly shorter in Group B and significantly longer in Group BD than the other two groups. Pain score at rest in Group B at 0^th hours was significantly higher than that of Group BD and VAS pain score Group BD at 2^nd hours was significantly lower than the other two groups. There was no significant difference between the groups regarding tramadol consumption and the requirement of rescue analgesics.

CONCLUSION:

Dexmedetomidine and ketamine can be added to the bupivacaine for the TAP block without major side-effects. The combination of dexmedetomidine and bupivacaine provides better analgesia in the first postoperative 2^nd hour than other groups and hence extends the time to the first analgesic demand.

Ultrasound-guided transversus abdominis plane block using ropivacaine and dexmedetomidine in patients undergoing caesarian sections to relieve post-operative analgesia: A randomized controlled clinical trial

Dexmedetomidine, which is a highly selective α2 adrenoreceptor agonist, enhances the analgesic efficacy and prolongs the analgesic duration when administered in combination with local anesthetics. The current study aimed to evaluate the effects of dexmedetomidine combined with ropivacaine in ultrasound-guided transversus abdominis plane (TAP) block on post-operative analgesia following cesarean section (CS). A total of 70 patients scheduled for CS were divided randomly into 2 groups: The ropivacaine (R) group, in which patients were administered bilateral 20 ml 0.3% ropivacaine and 2 ml 0.9% normal saline, and the dexmedetomidine (RD) group, in which patients were administered bilateral 20 ml 0.3% ropivacaine and 2 ml dexmedetomidine (0.5 µg/kg). The primary outcome was pain-free duration, and secondary outcomes included heart rate (HR) and mean blood pressure (MBP) measurements, visual analogue scale (VAS) pain scores, number of patients who required rescue analgesic, time to first request for analgesia and patient satisfaction. There was no significant difference in HR and MBP between the two groups at 1 h post-surgery (P>0.05). However, VAS pain scores decreased at 6 and 8 h post-surgery [2 (1-2) vs. 0 (0-0.25) and 2 (2-3) vs. 0 (0-1), respectively; P<0.05], pain-free duration was prolonged (5.91±1.08 vs. 9.62±1.46 h; P<0.05), the number of patients who required rescue analgesic was reduced (19 vs. 9; P<0.05), the time to first request for analgesia was prolonged (7.10±1.21 vs. 11.60±2.11 h; P<0.05) and patient satisfaction was improved [3.5 (3-4) vs. 4 (4-5); P<0.05] in the RD group compared with the R group. Furthermore, no bradycardia or hypotension was observed. In conclusion, the results of the present study demonstrated that adding 0.5 µg/kg dexmedetomidine to 0.3% ropivacaine used in TAP block in patients undergoing CS prolonged pain-free duration, decreased VAS pain scores, reduced the number of patients who required rescue analgesic, prolonged the time to first request for analgesia and improved the patient satisfaction without serious side effects.

Dexmedetomidine as an Adjuvant to Local Anesthetics in Transversus Abdominis Plane Block: A Systematic Review and Meta-analysis

OBJECTIVES

The objective of this meta-analysis was to evaluate the analgesic effects of dexmedetomidine (DEX) in transversus abdominis plane (TAP) blocks for abdominal surgery.

METHODS

Electronic databases, including PubMed, EMBASE, Chinese National Knowledge Infrastructure (CNKI), Wan Fang, and the Cochrane Library, were conducted to collect the randomized controlled trials (RCTs) from inception to March 2018. RCTs investigating the impact of adding DEX to local anesthetics for TAP blocks were included in this analysis. Pain scores (at rest and movement), opioid consumption, the duration of the TAP block and the common adverse effects were analyzed.

RESULTS

Twenty published trials including 1212 patients met the inclusion criteria. The addition of DEX significantly reduced pain scores 8 hours postoperatively at rest (WMD, -0.78; 95% CI, -1.27 to -0.30; P=0.001), 4 hours postoperatively on movement (WMD, -1.13; 95% CI, -1.65 to -0.60; P<0.001), and opioid consumption (WMD, -13.71; 95% CI, -17.83 to -9.60; P<0.001) when compared with control group. Furthermore, perineural DEX significantly prolonged the duration of the TAP block (WMD, 3.33; 95% CI, 2.85 to 3.82; P<0.001). It did not affect the incidence of postoperative nausea and vomiting, hypotension, bradycardia, somnolence, or pruritus.

CONCLUSIONS

DEX is a potential anesthetic adjuvant that can facilitate better postoperative analgesia, reduce postoperative analgesic requirements, and prolong the local anesthetic effect when administered in TAP blocks.