Objectives: To determine whether perioperative administration of ropivacaine hydrochloride with epinephrine decreases postoperative pain following adenotonsillectomy and to determine the pharmacokinetics of ropivacaine following injection.
Design: Prospective, randomized, double-blind clinical trial.
Setting: University pediatric ambulatory center.
Participants: A total of 130 children, aged 2 to 12 years, undergoing adenotonsillectomy.
Intervention: Patients received injections, in the tonsillar fossae, of isotonic sodium chloride solution or 0.5% ropivacaine hydrochloride with epinephrine immediately following tonsillectomy.
Main outcome measures: Modified objective pain score, time to 100 mL of oral intake, serial plasma ropivacaine levels, use of analgesics, incidence of retching and emesis, and other symptoms.
Results: Fifty-three patients (80%) in the ropivacaine group had detectable plasma levels in at least 3 of the 4 measurement time periods. The mean +/- SD peak concentration (C(max)) was 0.71 +/- 0.33 micro g/mL and the half-life was 0.96 hours. The average modified objective pain scores over all time points favored the placebo group (P =.06 test of between-subjects effects). Similarly, the average behavior score over time favored the placebo group (P =.046 test of between-subjects effects). Neck pain was better in the placebo group when averaged over postoperative days 1, 3, 7, and 14 (P =.04). The percentage of patients who had retching in the recovery room was greater in the ropivacaine group (41% vs 19%, P =.006).
Conclusions: The injection of 0.5% ropivacaine with epinephrine immediately following adenotonsillectomy results in a measurable plasma level. Ropivacaine with epinephrine injection does not reduce pain postoperatively and adversely affects behavior scores, neck pain scores, and retching frequency compared with placebo. Ropivacaine with epinephrine injection for postoperative analgesia is not recommended for this patient population.