Dose effect of local anesthetics on analgesic outcomes for the transversus abdominis plane (TAP) block in children: a randomized, double-blinded, clinical trial.

Abstract

Current knowledge on local anesthetic dosage for the TAP block in pediatric patients is very limited. To evaluate the effect of two escalating local anesthetic doses on postsurgical analgesic outcomes in children receiving a TAP block. The study was a prospective, randomized, double-blinded, clinical trial. Children (<8 years) were randomized to one of the two intervention groups: TAP block with bupivacaine at a dose of 2.5 mg · kg(-1) or 1.25 mg · kg(-1). Analgesic outcomes included pain scores in the postanesthesia care unit (PACU), time to analgesic requirement and total number of analgesic requirements. Thirty-six patients were recruited in the study. Pain scores in PACU were not different between study groups. The total number of analgesic dosage required in 24 h after surgery was higher in the lower dose group, median (IQR) of 4 (3 to 5) compared to 2.5 (1.5 to 3) in the greater dose group, P = 0.03. There was a clinically but not statistically significant difference in the time to first analgesic requirement in the 2.5 mg · kg(-1) group, median (IQR) of 248 (130 to 367) minutes compared to 146 (95 to 261) minutes in the 1.25 mg · kg(-1) dose group, P = 0.15. The use of higher local anesthetic doses for the TAP block in children does not provide benefits on early pain scores but seems to improve analgesic duration and decrease the need for additional analgesics over 24 h after surgery. The use of higher, but yet safe, local anesthetic dosages for TAP blocks is a viable strategy to improve analgesia in children.