Nonopioid (Dexmedetomidine, Dexamethasone, Magnesium) Adjuvant to Ropivacaine Caudal Anesthesia in Pediatric Patients Undergoing Infraumbilical Surgeries: A Comparative Study

Comparison of Analgesic Efficacy of Dexamethasone versus Tramadol in Combination with Ropivacaine in Caudal Anesthesia for Children Undergoing Lower Abdominal Surgeries

Background:

Caudal anesthesia has emerged as a reliable and effective anesthetic technique in the pediatric age group. However, the limited duration of action of the local anesthetic drugs proves to one of the major hindrances in the complete utilization of caudal block as an effective analgesic technique. To overcome this shortcoming, adjuvant drugs were introduced into clinical practice.

Aim:

Our aim was to determine which of the two drugs – dexamethasone and tramadol – serves as a better adjuvant for caudal analgesia in pediatric patients.

Settings and Design:

This was a prospective, randomized, double-blind study that comprised 90 American Society of Anesthesiologist (ASA) physical status I and II pediatric patients posted for lower abdominal surgeries.

Materials and Methods:

Ninety ASA physical status I and II children aged 5–12 years posted for lower abdominal surgeries were chosen. They were randomly divided into three groups – Group R received 0.5 ml.kg⁻¹ of 0.2% ropivacaine plus 0.9% normal saline; Group T received 0.5 ml.kg⁻¹ of 0.2% ropivacaine plus 2 mg.kg⁻¹ tramadol; and Group D received 0.5 ml.kg⁻¹ of 0.2% ropivacaine plus 0.1 mg.kg⁻¹ dexamethasone. Postoperative pain was assessed using a modified objective pain score and time to first rescue analgesia (duration of sensory block) was recorded. Postoperative sedation and any other postoperative adverse effects were noted.

Statistical Analysis:

Student's independent t-test was employed for comparing continuous variables and Chi-square test for categorical variables. Kruskal–Wallis test was used for postoperative pain and sedation score data.

Results:

The duration of sensory block was significantly longer with dexamethasone than tramadol. No significant postoperative sedation or any other adverse effect was noted in any patient.

Conclusion:

Dexamethasone is superior to tramadol as an adjuvant to ropivacaine for pediatric lower abdominal surgeries.

Efficacy and safety of caudal dexmedetomidine in pediatric infra-umbilical surgery: a meta-analysis and trial-sequential analysis of randomized controlled trials

BACKGROUND

Dexmedetomidine is used as a local-anesthetics adjuvant in caudal block to prolong analgesia in pediatric infra-umbilical surgery.

OBJECTIVE

We evaluated the analgesic efficacy and safety of the addition of caudal dexmedetomidine to local anesthetics (vs local anesthetics alone) in pediatric infra-umbilical surgery.

EVIDENCE REVIEW

We searched 10 databases for randomized controlled trials (RCTs) of pediatric patients undergoing infra-umbilical surgery, comparing caudal block with and without dexmedetomidine as local anesthetic adjuvant. We performed a frequentist random-effects meta-analysis (R statistical package). We analyzed continuous outcomes as a ratio of means (ROM) and dichotomous data as relative risk (RR), along with 95% CI. We included 19 RCTs (n=1190 pediatric patients) in the meta-analysis. The primary outcome was duration of analgesia (defined as 'the time from caudal injection to the time at which the study-specific pain score was greater than a cut-off threshold').

FINDINGS

Data from 19 included RCTs (n=1190) suggested that compared with control (mean duration 346 min), the addition of caudal dexmedetomidine significantly prolonged the duration of analgesia (ratio of means 2.14, 95% CI 1.83 to 2.49, p<0.001; 'moderate' evidence). Trial-sequential analysis showed adequate 'information size' for the primary outcome. Caudal dexmedetomidine also reduced the number of analgesic administrations ('low' evidence), total acetaminophen dose ('moderate' evidence) and the risk of emergence delirium ('moderate' evidence). There were no significant differences in adverse effects such as hypotension, bradycardia, post-operative nausea and vomiting, urinary retention and respiratory depression.

CONCLUSIONS

Our results suggest that the addition of dexmedetomidine to local anesthetic in caudal block significantly improves the duration of analgesia and reduces the analgesic requirements, while maintaining a similar risk-profile compared with local anesthetic alone. Further data on neurological safety are needed.

Effect of magnesium added to local anesthetics for caudal anesthesia on postoperative pain in pediatric surgical patients: A systematic review and meta-analysis with Trial Sequential Analysis

BACKGROUND

Magnesium has been investigated as an adjuvant for neuraxial anesthesia, but the effect of caudal magnesium on postoperative pain is inconsistent. The aim of this systematic review and meta-analysis was to evaluate the analgesic effect of caudal magnesium.

METHODS

We searched six databases, including trial registration sites. Randomized clinical trials reporting the effect of caudal magnesium on postoperative pain after general anesthesia were eligible. The risk ratio for use of rescue analgesics after surgery was combined using a random-effects model. We also assessed adverse events. The I2 statistic was used to assess heterogeneity. We assessed risk of bias with Cochrane domains. We controlled type I and II errors due to sparse data and repetitive testing with Trial Sequential Analysis. We assessed the quality of evidence with GRADE.

RESULTS

Four randomized controlled trials (247 patients) evaluated the need for rescue analgesics. In all four trials, 50 mg of magnesium was administered with caudal ropivacaine. The results suggested that the need for rescue analgesia was reduced significantly by caudal magnesium administration (risk ratio 0.45; 95% confidence interval 0.24-0.86). There was considerable heterogeneity as indicated by an I2 value of 62.5%. The Trial Sequential Analysis-adjusted confidence interval was 0.04-5.55, indicating that further trials are required. The quality of evidence was very low. The rate of adverse events was comparable between treatment groups.

CONCLUSION

Caudal magnesium may reduce the need for rescue analgesia after surgery, but further randomized clinical trials with a low risk of bias and a low risk of random errors are necessary to assess the effect of caudal magnesium on postoperative pain and adverse events.

TRIAL REGISTRATION

University Hospital Medical Information Network Clinical Trials Registry UMIN000025344.