Comparing the Duration of the Analgesic Effects of Intravenous and Rectal Acetaminophen Following Tonsillectomy in Children

Background: Postoperative pain control (especially, after adenotonsillectomy) has a very important effect on recovery time, hospitalization duration, hemodynamic disorders, bleeding, nausea, vomiting and medical costs. Objectives: The aim of this study was to investigate and compare the effects of intravenous and rectal acetaminophen on controlling post-adenotonsillectomy pain in children, and duration of their analgesic effects. Patients and Methods: In this randomized double-blinded clinical trial, 96 children aged 4 - 10 years old with ASA physical status I or II who were candidates for adenotonsillectomy surgery in Amir-al-Momenin Hospital, Rasht, Iran were entered into the study and randomly divided into two equal groups. Anesthesia in both groups was induced injecting fentanyl-thiopental and at racurium; afterwards is of lurane was used to maintain anesthesia. After anesthesia induction, one group received intravenous and the other one, rectal acetaminophen, and were later compared based on CHIPPS criteria. Results: Data analysis indicated a significant relationship between reduction of postoperative pain and the use of intravenous or rectal acetaminophen (P = 0.0001); in group receiving IV cetaminophen, only 10.4% of patients had no pain whereas in group receiving rectal acetaminophen, this number reached 43.8%. Also, on 4 and 6 hour time intervals, pain in rectal acetaminophen receiving group was less than that in IV acetaminophen receiving group (P < 0.05). Demand for additional analgesic medication in rectal acetaminophen receiving group was less than that in IV group (P = 0.0001). Conclusions: Post-operative pain in rectal acetaminophen group was less than that in intravenous acetaminophen group, and rectal acetaminophen group demanded their first additional analgesic medication later.