Caudal Analgesia for Hypospadias in Pediatrics: Comparative Evaluation of Adjuvants Dexamethasone and Dexmedetomidine Combination versus Dexamethasone or Dexmedetomidine to Bupivacaine: A Prospective, Double-Blinded, Randomized Comparative Study

Abstract

Background: Caudal block is the most commonly used regional anesthetic technique in pediatric surgeries; different additives have been used for better and safer outcome.

Aim: The aim of this study is to compare the combination of dexamethasone and dexmedetomidine as adjuvants to bupivacaine versus using each agent solely with bupivacaine in pediatric caudal block as regards their efficiency in pain relief (the duration of postoperative analgesia, first time to request analgesia, and modified objective pain score [MOPS]).

Study design: This was a prospective, double-blinded, randomized study.

Patients and methods: Patients and Methods: Sixty-three children scheduled for hypospadias surgery wererandomized into three groupsaccording to the adjuvant drug added to caudal bupivacaine : Group I (n = 21): dexamethasone 0.1 mg/kg + 0.5 mg/kg bupivacaine 0.25%, Group II (n = 21): dexmedetomidine0.01 μg/kg + 0.5 mg/kg bupivacaine 0.25% and Group III (n = 21): dexamethasone 0.1 mg/kg + dexmedetomidine 0.01 μg/kg + 0.5 mg/kgbupivacaine 0.25%. Intraoperative and postoperative hemodynamics were recorded. In postoperative anesthesia care unit and then the ward, MOPS and sedation score were recorded at 30 min and 1, 2, 3, 6 and 12 h. Further, the time of first analgesic request and side effects were recorded.

Statistical analysis: Categorical data were presented as frequencies (%) and analyzed using Chi-square test. Continuous data were presented as mean (standard deviation) and median (quartiles). Continuous data were analyzed using one-way analysis of variance for single measures and two-way mixed model for repeated measures. Kaplan-Meier analysis was performed for the duration of analgesia.

Results: In Group III, MOPS was lower than Groups I and II at the study times. Further, Group III had prolonged time for first request of analgesic. Sedation scores were prolonged in Group III and Group II than in Group I. There was a reduction in heart rates in Group III more than Group I and Group II but with no significant difference. However, there was a significant reduction in mean arterial blood pressure 30 min intraoperatively and postoperatively in Group III as compared to Groups I and II.

Conclusion: The addition of combined dexmedetomidine at a dose of 1 μg/kg and dexamethasone 0.1 mg/kg to caudal bupivacaine seemed to be an attractive alternative to each drug if used alone with more prolonged analgesia and almost no adverse effects.

Keywords: Caudal block; combined dexamethasone and dexmedetomidine; hypospadias surgery; pediatric surgery; postoperative analgesia.

Figure 1

Consort chart

Figure 2

*P < 0.05 significant difference between Dexmedetomidine group and decadron group, ^#P < 0.05 significant difference between Combined (dex + decadron) group and decadron group, ^πP < 0.05 significant difference between Dexmedetomidine group and combined group. T1 ½ h, T2 1hr, T3 2hr, T4 3hr, T5 6hr, T6 12hr postoperatively

Figure 3

Heart rate changes at different times in each group. Data expressed as mean ± standard deviation. T1 Baseline, T2 at induction, T3 30 min intraoperative, T4 postoperative

Figure 4

Blood pressure changes at different times in each group. Data expressed as mean ± standard deviation. T1 Baseline, T2 at induction, T3 30 min intraoperative, T4 postoperative

Figure 5

Sedation score between three groups at different study times. Data expressed as median (interquartile range). T1 ½h, T2 1 h, T3 2 h, T4 3 h, T5 6 h, T6 12 h postoperatively

Figure 6

Kaplan–Meier graph presenting first time to analgesia difference between the three groups