Postoperative Analgesia with Epidural Dexmedetomidine Compared with Clonidine following Total Abdominal Hysterectomies: A Prospective Double-blind Randomized Trial

Methods of prolonging the effect of caudal block in children

Caudal epidural blockade is one of the most frequently administered regional anesthesia techniques in children. It is a supplement during general anesthesia and for providing postoperative analgesia in pediatrics for sub-umbilical surgeries, especially for genitourinary surgeries. However, the duration of the analgesic effect is occasionally unsatisfactory. In this review, we discuss the main advantages and disadvantages of different techniques to prolong postoperative analgesia for single-injection caudal blockade in children. A literature search of the keywords "caudal", "analgesia", "pediatric", and "children" was performed using PubMed and Web of Science databases. We highlight that analgesic quality correlates substantially with the local anesthetic's type, dose, the timing relationship between caudal block and surgery, caudal catheterization, and administration of epidural opioids or other adjuvant drugs.

Epidural nalbuphine versus dexmedetomidine as adjuvants to bupivacaine in lower limb orthopedic surgeries for postoperative analgesia: a randomized controlled trial

BACKGROUND

Administration of adjuvant drugs epidurally in combination with local anesthetics offers new dimensions in the management of postoperative pain. This study aimed to compare the addition of either nalbuphine or dexmedetomidine to epidural bupivacaine for postoperative analgesia in lower limb orthopedic surgeries under combined spinal-epidural anesthesia.

METHODS

This prospective randomized double-blind study included 69 patients scheduled for lower limb orthopedic surgeries. Anesthesia was started with 15 mg hyperbaric bupivacaine 0.5% intrathecally, and then an epidural bolus dose of 12 ml (10 ml 0.25% bupivacaine with 2 ml normal saline in group C, 2 ml (10 mg) nalbuphine in group N or dexmedetomidine 2 ml (100 µg) in group D was administered when sensory regression to T10. Postoperatively, when visual analogue scale (VAS) was ≥ 3, an epidural top-up dose of 8 ml (6 ml 0.25% bupivacaine plus 2 ml normal saline in group C, 2 ml (2 mg) nalbuphine in group N or 20 µg dexmedetomidine (2 ml) in group D was given. The primary outcome was to evaluate the duration of postoperative analgesia and secondary outcomes were any side effects and patient satisfaction.

RESULTS

The onset of epidural analgesia was 17.83 ± 2.53 versus 13.39 ± 1.27 versus 12.17 ± 1.27 min in groups C, N and D, respectively (p value < 0.001). The mean duration of analgesia was 241.3 ± 14.24 versus 318.38 ± 22.54 versus 365.87 ± 18.01 min in groups C, N and D, respectively (p value < 0.001). The mean sedation score was less in group C than group N and D (P < 0.001). The patient satisfaction score showed the lowest degree of satisfaction in group C (p value < 0.001). Top-up doses consumed and total analgesic requirements were lower in groups N and D than in group C. There was a statistically significant difference between the studied groups regarding VAS over time (p value < 0.001), intraoperative bradycardia (p value 0.029), and shivering (p value 0.029).

CONCLUSION

The addition of either nalbuphine or dexmedetomidine to epidural bupivacaine was effective for postoperative analgesia in terms of onset, duration, and patient satisfaction with the superiority of dexmedetomidine over nalbuphine.

TRIAL REGISTRATION

Approval from the research ethics committee of the Faculty of Medicine, Zagazig University was obtained with the reference number (ZU-IRB#:7045-15-8-2021) and it was registered under clinicaltrials.gov (NCT05041270) on registration date 13/09/2021.

Dexmedetomidine or Fentanyl, Which One Is Better as an Adjunct Drug in Epidural Anesthesia and Causes More Postoperative Pain Reduction? A Comparative Study, a Randomized Clinical Trial

Objectives

This study compared dexmedetomidine to fentanyl as an adjunct to ropivacaine for epidural anesthesia in patients undergoing femoral neck fracture surgery.

Methods

A total of 56 patients in two different groups with dexmedetomidine and fentanyl underwent the epidural anesthesia method by ropivacaine. This study compared the onset and duration of sensory block, duration of motor block, visual analog scale (VAS) analgesia, and sedation score. The VAS and hemodynamics (e.g., heart rate and mean arterial pressure) were measured every 5 to 15 minutes, then every 15 minutes to the end of the surgery, and then in the 1st, 2nd, 4th, 6th, 12th, and 24th hours after surgery.

Results

In the fentanyl group, the onset time of the sensory block was longer (P < 0.001), and the duration of the block was shorter than in the dexmedetomidine group (P = 0.045). In the fentanyl group, the onset time of motor block was longer than in the dexmedetomidine group (P < 0.001). The mean highest VAS score for each patient in the dexmedetomidine group was 4.9 ± 0.6, compared to the fentanyl group (5.8 ± 0.9), with a significant difference between the two groups (P < 0.001). The sedation score was higher from the 30th minute (P = 0.01) to the 120th minute (P = 0.04) in the patients of the dexmedetomidine group than in the fentanyl group. Side effects, such as dry mouth, hypotension, and bradycardia, were more common in the dexmedetomidine group, and nausea and vomiting were more common in the fentanyl group; however, there were no differences between the groups. There was no respiratory depression in both groups.

Conclusions

This study presented that dexmedetomidine as an adjuvant in epidural anesthesia for orthopedic femoral fracture surgery shortens the onset time of sensory and motor block, increases analgesia length, and prolongs anesthesia. Sedation with dexmedetomidine is better than fentanyl, with fewer side effects, and more effective as preemptive analgesia.

Clonidine as an Additive to Local Anesthetics in Caudal Block for Postoperative Analgesia in Pediatric Surgery: A Systematic Review and Meta-Analysis

Background: Clonidine is an anesthetic with favorable efficacy and safety profiles for caudal epidural block, but comparisons with other adjuvants need to be confirmed in pediatric patients. Aim: To investigate the effects of clonidine as an adjuvant in caudal epidural block to improve the intraoperative and postoperative analgesia in pediatric surgery. Methods: PubMed, Embase, and the Cochrane Library were searched for available papers published up to February 2021. The outcomes were pain score, duration of analgesia, complications, and number of analgesic requirements. The meta-analysis was performed using random-effects models. Results: Fifteen randomized controlled trials (RCTs) were included. There were no differences between clonidine and the control drug regarding the duration of analgesia (SMD = -0.71, 95%CI: -1.64, 0.23; I ² = 95.5%, P_{heterogeneity} < 0.001), pain score (SMD = 0.35, 95%CI: -0.28, 0.98; I ² = 80.8%, P_{heterogeneity} < 0.001), and requirement for additional analgesia (OR = 8.77, 95%CI: 0.70, 110.58, I ² = 81.9%, P_{heterogeneity} = 0.004), but using clonidine resulted in fewer complications than the control drugs (OR = 0.33, 95%CI: 0.20, 0.54, I ² = 21.8%, P_{heterogeneity} = 0.217). The sensitivity analysis showed that the results were robust. A publication bias was observed. Conclusion: Clonidine has the same efficacy as the other adjuvants for caudal epidural block for pediatric surgery but fewer complications. These results support clonidine as an adjuvant to local anesthetic, but additional studies should be conducted.

Comparative Study of the Adverse Events Associated With Adjuvant Use of Dexmedetomidine and Clonidine in Local Anesthesia

Background: Although clonidine and dexmedetomidine are used as alpha-2 agonists to improve the quality and duration of blockade induced by local anesthetics, no study has been reported to compare their associated adverse events in local anesthesia. The aim of this study is to compare the adverse events associated with the adjuvant use of dexmedetomidine and clonidine in local anesthesia.

Methods: A comprehensive search was performed to retrieve any reported adverse event associated with adjuvant use of dexmedetomidine and clonidine in local anesthesia from published literature up to 1 July 2020. Assessment of the quality of included studies was performed by the Jadad score. A comparison of any reported adverse event was made between interventions by pooling data from studies using a direct meta-analysis technique. Dichotomous outcomes were summarized as risk ratios. The review was performed according to PRISMA guideline.

Results: From 121 articles retrieved from the search finally 14 articles including 1,120 patients had eligibility criteria for including in the meta-analysis. No significant difference was observed between bradycardia/hypotension (OR = 1.17; 95 % CI = 0.66–2.10; P = 0.580; I² = 53.78 %, P = 0.027), nausea/vomiting (OR = 0.91; 95% CI = 0.59-1.42; P = 0.706; I² = 0.0 %, P = 0.940) dizziness/headache (OR = 1.10; 95% CI = 0.44–2.75; P = 0.831; I² = 0.0 %, P = 0.882) shivering (OR = 0.95 % CI = 0.50–1.66; P = 0.831; I² = 0.0 %, P = 0.920) and dry mouth (OR = 1.00; 95 % CI = 0.50–1.96; P = 0.996; I² = 0.0%, P = 0.900). No significant difference was observed in subgroup comparison of adverse events in the intravenous or local adjuvant use of the study drugs (p > 0.05).

Conclusion: There is no difference in adverse events associated with the intravenous or local adjuvant use of dexmedetomidine and clonidine in local anesthesia.

Influence of Epidural Ropivacaine with or without Dexmedetomidine on Postoperative Analgesia and Patient Satisfaction after Thoraco-Lumbar Spine Instrumentation: A Randomized, Comparative, and Double-Blind Study

Study Design

This was a prospective, randomized, and double-blind study.

Purpose

Thoraco-lumbar spine surgery is associated with severe postoperative pain and can cause chronic pain. We aimed to compare the impact of epidural ropivacaine with and without dexmedetomidine on postoperative analgesia after thoracolumbar spine instrumentation wherein an epidural catheter was placed by the surgeon intraoperatively.

Overview of Literature

Very few studies have reported the use of epidural dexmedetomidine in spine surgeries. When used via the epidural route, dexmedetomidine is safe and efficacious and is associated with reduced rescue analgesia consumption, increased duration of analgesia, reduced pain scores, but not with major hemodynamic adverse effects.

Methods

Total 60 American Society of Anesthesiologists I–III adult patients aged 18–65 years who were scheduled to undergo thoraco-lumbar spine instrumentation were randomly allocated into group RD (epidural ropivacaine+dexmedetomidine) or group R (epidural ropivacaine plus saline). We aimed to compare the total rescue analgesic consumption on postoperative day 0, 1, and 2. Moreover, we studied the time to first rescue analgesia with visual analogue scale score <4 and the overall patient satisfaction scores.

Results

There was no difference between the demographic characteristics of the two groups. The mean value of total rescue analgesia consumption was 162.5±68.4 mg in the RD group and 247.5±48.8 mg in the R group. The mean time to first rescue analgesia was 594.6±83.0 minutes in the RD group and 103.6±53.2 minutes in the R group. The mean patient satisfaction score was 4.2±0.7 in the RD group and 3.2±0.6 in the R group. No patient had any respiratory depression or prolonged motor blockade during the postoperative period.

Conclusions

This study demonstrated the superior efficacy, in terms of postoperative analgesia and patient satisfaction scores, of epidural ropivacaine plus dexmedetomidine over that of ropivacaine alone in patients undergoing surgery for thoraco-lumbar spine.