Efficacy of adjuvant dexmedetomidine on penile block for pediatric hypospadias repair

Abstract

The management of postoperative pain, particularly in younger children, presents a challenge due to their limited ability to articulate the intensity of pain, lower pain threshold, and restricted availability of approved analgesics for pediatric use. Peripheral nerve blocks may be favored over neuraxial blocks because they allow quicker mobilization after surgery. The present study aims to investigate the potential impact of adding dexmedetomidine to a local anesthetic (bupivacaine) on the analgesic efficacy in dorsal penile nerve block in hypospadias repair surgery. In this prospective double-blinded clinical trial, 50 children aged between 6 months and 6 years old undergoing hypospadias repair surgery participated. Analgesia was administered through a dorsal penile nerve block (DPNB) at the end of surgery. Participants were divided into two groups; one received bupivacaine alone, and the other received dexmedetomidine and bupivacaine in DPNB. Pain and sedation levels were assessed with FLACC score and MOAA/S score, respectively, at 0,1,2 and 4h after surgery. Vital signs and adverse effects were also recorded, including hemodynamic changes, nausea, and vomiting. There was no statistically significant difference in demographic variables. As illustrated in Figure, the median of FLACC score in group BD was significantly lower compared to group B at every measured time point. MOAA/S score was significantly lower in group BD than in group B (p<0.001), indicating a higher sedation level. None of the participants in either group experienced any adverse effect except for vomiting, which was not statistically significant (8% in group B vs. 4% in group BD, p>0.999). Several studies have documented the supplementary analgesic properties of dexmedetomidine when used in conjunction with local anesthetic during various surgical procedures and nerve blocks. The present study provides evidence for the additional analgesic efficacy of dexmedetomidine and bupivacaine in the context of dorsal penile nerve block during hypospadias repair surgery while not yielding any significant adverse outcomes. Although the patients in our study were monitored for 4h in the postanesthesia care unit (PACU), conducting a more comprehensive assessment of patients is advisable. The findings of our study indicate that incorporating dexmedetomidine alongside bupivacaine in dorsal penile nerve block during hypospadias repair surgery may lead to enhanced management of postoperative pain. The lack of adverse effects implies it may be a potentially safe supplementary pain reliever for surgical procedures.