Addition of dexmedetomidine or fentanyl to ropivacaine for transversus abdominis plane block: evaluation of effect on postoperative pain and quality of recovery in gynecological surgery

Dexmedetomidine adjunct to ropivacaine for ultrasound-guided transversus abdominis plane block for open inguinal hernia repair in the older adults: A randomised clinical trial

OBJECTIVE

The aim of this study was to evaluate the effect of adding dexmedetomidine to ropivacaine on pain relief and quality of recovery in older patients undergoing open inguinal hernia repair surgeries.

METHODS

This was a prospective and randomised clinical trial of 102 patients aged over 65 years who received an ultrasound-guided transversus open mesh herniorrhaphy abdominis plane (TAP) block with either 0.375% ropivacaine 20 ml (Group R, n = 47) or 0.375% ropivacaine combined with 1 μg/kg dexmedetomidine 20 ml (Group RD, n = 45) in the pre-anaesthesia care unit before elective open inguinal hernia surgeries. The primary outcome measure was Visual Analogue Scale (VAS) pain scores at rest and on movement at 2, 4, 8, 12 and 24 h and at 1 and 3 months' postoperatively. The secondary outcome measures were the incidence of post-operative delirium (POD), nausea and vomiting and the occurrence of side effects or complications on post-operative day 1.

RESULTS

Group RD had lower VAS scores at rest and on movement at 8 and 12 h postoperatively and a lower incidence of POD on the post-operative day 1 than Group R. Transient bradycardia was more frequent in Group RD than in Group R, and side effects or post-operative complications were reported in either group.

CONCLUSION

The addition of dexmedetomidine to ropivacaine in a TAP block enhances postoperative analgesia during hospitalisation and improves the quality of recovery without affecting chronic pain in older patients undergoing open inguinal hernia repair surgery.

Impact of adding opioids to paravertebral blocks in breast cancer surgery patients: A systematic review and meta-analysis

BACKGROUND

Several breast cancer studies have reported the use of adjuvant opioids with the paravertebral block (PVB) to improve outcomes. However, there is no level-1 evidence justifying its use.

AIM

To elucidate if the addition of opioids to PVB improves pain control in breast cancer surgery patients.

METHODS

We conducted an electronic literature search across PubMed, Embase, Scopus, and Google Scholar databases up to October 20, 2020. Only randomized controlled trials (RCTs) comparing the addition of opioids to PVB with placebo for breast cancer surgery patients were included.

RESULTS

Six RCTs were included. Our meta-analysis indicated significantly reduced 24-h total analgesic consumption with the addition of opioids to PVB as compared to placebo [standardized mean difference (SMD) -1.57, 95% confidence interval (CI): -2.93, -0.21, I² = 94%]. However, on subgroup analysis, the results were non-significant for studies using single PVB (SMD: -1.76, 95%CI: -3.65, 0.13 I² = 95.09%) and studies using PVB infusion (SMD: -1.30, 95%CI: -4.26, 1.65, I² = 95.49%). Analysis of single PVB studies indicated no significant difference in the time to first analgesic request between opioid and placebo groups (mean difference -11.28, 95%CI: -42.00, 19.43, I² = 99.39%). Pain scores at 24 h were marginally lower in the opioid group (mean difference -1.10, 95%CI: -2.20, 0.00, I² = 0%). There was no difference in the incidence of postoperative nausea and vomiting between the two groups.

CONCLUSION

Current evidence suggests a limited role of adjuvant opioids with PVB for breast cancer surgery patients. Further homogenous RCTs with a large sample size are needed to clarify the beneficial role of opioids with PVB.

Analgesic efficacy of ultrasound-guided transversus abdominis plane block for laparoscopic gynecological surgery: a randomized controlled trial

Background

This study aimed to determine whether ultrasound-guided transversus abdominis plane (TAP) block is more effective in reducing postoperative pain and analgesic consumption than local anesthetic infiltration (LAI) at the port site for elective laparoscopic gynecological surgeries.

Methods

Eighty patients with the American Society of Anesthesiologists status I/II undergoing laparoscopic gynecology surgery were enrolled for this randomized control trial. After general anesthesia was administered, patients in group C received LAI at each port site, and patients in group T received bilateral ultrasound-guided TAP block. Postoperative pain was assessed at time intervals of 1/2, 2, 4, 6, 8, and 24 h using the numeric rating scale (NRS). Clinical metrics such as postoperative analgesic diclofenac consumption, need for rescue fentanyl, nausea-vomiting scores, and antiemetic requirements were also recorded.

Results

Seventy-four patients were included in the final analysis. Postoperatively, patients in group T had significantly lower NRS than those in group C (P < 0.05). The highest difference in the postoperative NRS was observed at 2 h (median [1Q, 3Q]; group C = 3 [2, 4]; group T = 1 [0, 2]; P < 0.001). A statistically significant difference was observed in the frequency of diclofenac (75 mg intravenous) requirement between the groups (P = 0.010). No significant difference was observed between the groups in need of rescue fentanyl or antiemetic and the nausea-vomiting scores.

Conclusions

In patients undergoing laparoscopic gynecological surgery, ultrasound-guided TAP block provided greater postoperative analgesic benefits in terms of lower NRS and reduced analgesic requirements than port site LAI.

An Image Study on Local Anesthetic Spread in Healthy Volunteers Receiving Subcostal Exterior Semilunaris Transversus Abdominis Plane (SE-TAP) Block

Background

Despite the popularity of the ultrasound-guided transversus abdominis plane (TAP) block and the diversity of advancing approaches, the extent of injectate spread limits its clinical benefits. This study used three-dimensional computed tomography (3D-CT) imaging and a cold stimulus to evaluate the spread of a local anesthetic injected through the subcostal exterior semilunaris to transversus abdominis plane (SE-TAP) block in healthy volunteers.

Methods

Eight healthy volunteers received a right-side ultrasound-guided SE-TAP block with 25 mL of 0.3% ropivacaine. The sensory block was assessed by a cold stimulus at 30 min, 2 h, 4 h, and 8 h following the SE-TAP block according to the 18-zone division method. A CT scan and 3D imaging were performed after the first sensory assessment.

Results

The injectate spread into the transversus abdominis space in all eight volunteers. 3D imaging confirmed that the injectate spread extensively along the costal margin in the plane of the transverse abdominis muscle and that it surpassed the semilunaris. Regarding the assessment using cold stimulus, five of six anterior zones and three of six lateral zones obtained successful rates of cutaneous sensory block higher than 75% 30 min after SE-TAP. Sensory block was achieved in the ventral dermatomes of all volunteers.

Conclusion

Our study showed that the SE-TAP injectate, which was administered using simple anatomical landmarks to provide reliable analgesia for abdominal surgery, consistently spread along the costal margin and extensively blocked cutaneous sensitivity in the anterior and lateral abdominal walls.

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.