Background and Objectives Unipolar sternocleidomastoid release with myectomy (USRM) for correction of congenital muscular torticollis in pediatric patients produces moderate to severe postoperative pain. The objective of this trial was to examine the effect of ultrasound-guided intermediate cervical plexus block on postoperative pain after USRM.

Methods Thirty-two patients (1–7 years old) were enrolled in this parallel-group, patient- and observer-blinded, randomized controlled trial. In the block group, 0.25% ropivacaine (0.2 mL/kg) was injected into the interfascial plane between the sternocleidomastoid muscle and the prevertebral fascia under ultrasound guidance at the fourth to fifth cervical vertebral level. The primary outcome measure was the face, legs, activity, cry, and consolability (FLACC) score at 5 minutes after entering the postanesthesia care unit (PACU), and secondary outcome measures were the FLACC score at discharge from the PACU and 3, 6, and 24 hours after operation and the use of rescue analgesic in the PACU and ward.

Results The FLACC score at 5 minutes after admission to the PACU was significantly reduced (3 vs 8; median difference, 4; 95% confidence interval, 1–7; P = 0.044), and the fentanyl dose and the number of patients requiring rescue analgesics in the PACU were significantly lower (0.0 vs 0.5 μg/kg, P = 0.014; 5 [29.4%] vs 12 [75.0%], P = 0.032) in the block than in the control group. However, after discharge from PACU, there was no difference in FLACC scores and use of rescue analgesics between groups.

Conclusions Ultrasound-guided intermediate cervical plexus block decreased immediate postoperative pain and opioid requirements in the PACU in pediatric patients who underwent USRM.

Clinical Trial Registration This study was registered at ClinicalTrials.gov, identifier NCT02651311.