Preoperative High-Dose Oral Paracetamol for Postoperative Analgesia in Children Undergoing Tonsillectomy"

Effect of Preoperative Oral Paracetamol Loading Dose Versus Standard Dose on Postoperative Opioid Consumption in Pediatric Tonsillectomy With Multimodal Analgesia: A Randomized Controlled Trial

This randomized clinical trial compares two different preoperative doses of oral paracetamol (acetaminophen) in children undergoing elective tonsillectomy. The aim is to determine whether a higher loading dose (30 mg/kg) decreases the need for opioid rescue medication after surgery compared with the standard dose (15 mg/kg), when used as part of a multimodal pain management approach. Children aged 3 to 15 years will be randomly assigned to receive either 30 mg/kg or 15 mg/kg of oral paracetamol before surgery. All participants will receive the same standard anesthesia and postoperative pain management. The primary outcome is the total amount of rescue opioid (fentanyl) required during the first 12 hours after surgery. Secondary outcomes include postoperative pain scores and the occurrence of side effects such as nausea and vomiting. This study seeks to determine whether a higher initial dose of paracetamol offers additional clinical benefits in pediatric tonsillectomy with multimodal analgesia.

Study Overview

• Status: Not yet recruiting
• Conditions: Post Operative Analgesia; Tonsillectomy With or Without Adenoidectomy
• Intervention / Treatment: Drug: Paracetamol (acetaminophen)

Detailed Description

Tonsillectomy is one of the most commonly performed surgical procedures in children, yet it is often associated with significant postoperative pain. Effective pain management is critical to minimizing complications, and a multimodal approach to analgesia is recommended to reduce opioid consumption while providing effective pain relief. Paracetamol is a widely used and safe analgesic component within these multimodal regimens.

While previous studies indicate that an oral paracetamol loading dose of 30 mg/kg effectively reduces fever and provides consistent serum levels, there remains a limited direct comparison of clinical outcomes between an oral preoperative loading dose and a standard dose within preemptive standardized multimodal analgesia protocols for pediatric tonsillectomy. This randomized controlled trial aims to evaluate whether an oral paracetamol loading dose yields a superior opioid-sparing effect compared to a standard dose in this patient population.

A total of 54 pediatric patients, aged 3 to 15 years with ASA physical status I-III, scheduled for elective tonsillectomy (with or without adenoidectomy) will be enrolled. Participants will be randomized in a 1:1 ratio into two groups:

Group L (Loading Dose): Will receive a preoperative oral paracetamol dose of 30 mg/kg (adjusted body weight, maximum 1000 mg) 30-60 minutes before anesthesia induction.

Group C (Standard Dose): Will receive a preoperative oral paracetamol dose of 15 mg/kg (maximum 1000 mg) 30-60 minutes before anesthesia induction.

To maintain strict quadruple blinding, both groups will receive the same commercial paracetamol syrup formulation (250 mg/5 mL) prepared in opaque oral syringes by independent research staff. Participants, caregivers, treating anesthesiologists, surgeons, and outcome assessors (ward nurses) will be blinded to the group allocation.

All participants will undergo general anesthesia with endotracheal intubation and receive a standardized multimodal analgesia protocol. This protocol includes preoperative ibuprofen (10 mg/kg), intraoperative IV dexamethasone (0.2 mg/kg), local infiltration with 1% lidocaine with epinephrine, IV ondansetron (0.1 mg/kg), and postoperative oral paracetamol (15 mg/kg every 6 hours), ibuprofen (10 mg/kg every 8 hours).

Postoperative pain will be evaluated using age-appropriate validated tools: the revised FLACC scale for children aged 3-7 years (or those with cognitive impairment) and the Numerical Rating Scale (NRS) for children aged 7-15 years. Pain assessments will occur upon arrival at the post-anesthesia care unit (PACU) (hour 0), before transfer to the ward (hour 1), and at 6 and 12 hours postoperatively on the ward. If a patient reports a pain score of 4 or greater, rescue IV fentanyl (0.25 mcg/kg) will be administered according to protocol guidelines.

The primary outcome of the study is the total postoperative opioid (fentanyl) consumption within the first 12 hours after surgery. Secondary outcomes include postoperative pain scores at multiple time points, time to first rescue opioid requirement, the number of rescue opioid doses administered, and the incidence of adverse events such as nausea, vomiting, and sedation. The observation window is confined to the initial 12 hours post-surgery because most patients are discharged within 24 hours without oral opioid prescriptions, and the drug's pharmacological effects are expected to be most pertinent during this early recovery phase.

• Study Type: Interventional
• Enrollment (Estimated): 54
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Waranya Lertpaitoonpan, MD; Phone Number: +66892039291; Email: waranya.anesthtu@gmail.com

Study Locations

• Thailand
  • Changwat Pathum Thani
    • Pathum Thani, Changwat Pathum Thani, Thailand, 12120
      • Thammasat University
      • Contact: Waranya Lertpaitoonpan, MD; Phone Number: +66892039291; Email: waranya.anesthtu@gmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Children aged 3 to 15 years
2. ASA physical status I-III
3. Scheduled for elective tonsillectomy with or without adenoidectomy

Exclusion Criteria:

1. Known allergy or contraindication to paracetamol or any agents in the study protocol
2. Chronic opioid use

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: High-dose oral paracetamol (30 mg/kg); Participants receive oral paracetamol 30 mg/kg approximately 30-60 minutes before surgery.	Drug: Paracetamol (acetaminophen); Oral paracetamol administered preoperatively as a single dose ( 15 mg/kg or 30 mg/kg, depending on assigned arm).
Active Comparator: Standard-dose oral paracetamol (15 mg/kg); Participants receive oral paracetamol 15 mg/kg approximately 30-60 minutes before surgery.	Drug: Paracetamol (acetaminophen); Oral paracetamol administered preoperatively as a single dose ( 15 mg/kg or 30 mg/kg, depending on assigned arm).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Total postoperative opioid consumption	Total postoperative opioid consumption (expressed as cumulative IV fentanyl dose in mcg/kg) was administered.	0-12 hours after surgery

Collaborators and Investigators

• Sponsor: Thammasat University

Study record dates

Study Major Dates

• Study Start (Estimated): March 1, 2026
• Primary Completion (Estimated): September 1, 2026
• Study Completion (Estimated): November 1, 2026

Study Registration Dates

• First Submitted: March 5, 2026
• First Submitted That Met QC Criteria: March 5, 2026
• First Posted (Actual): March 11, 2026

Study Record Updates

• Last Update Posted (Actual): March 11, 2026
• Last Update Submitted That Met QC Criteria: March 5, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: acetaminophen; tonsillectomy; postoperative analgesia; paracetamol; pediatric anesthesia; multimodal analgesia
• Additional Relevant MeSH Terms: Organic Chemicals; Anilides; Amides; Aniline Compounds; Amines; Acetanilides; Acetaminophen
• Other Study ID Numbers: MTU-EC-AN-0-306/68

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No