Elective Total Abdominal Hysterectomy With Preoperative Analgesia Intravenous Paracetamol Versus Placebo

We conducted a randomized, double-blind, placebo-controlled trial at our hospital (QSMH) , including women undergoing elective TAH The trial was conducted between October 2024 (two thousand twenty-four) and May 2025 (two thousand twenty-five) , with approval from the institutional review board.

Participants were randomized 1:1 (one to one) to receive IV paracetamol 1 g or IV normal saline, administered in the operating room before induction of anesthesia, Postoperatively, pain was assessed intermittently using the NRS (์numeric rating scale) at 1, 6, 12, and 24 hours, with morphine 0.1 mg/kg (zero point one milligrams per kilogram) Intravenous provided on demand.

The primary outcome was the number of morphine injections within 24 hours; the secondary outcome was NRS pain scores.

Inclusion criteria

• Female patients aged 30-50 years.
• Scheduled to undergo total abdominal hysterectomy (TAH) at Queen Savang Vadhana Memorial Hospital at Sriracha
• No history of allergy to paracetamol (acetaminophen) or morphine.
• Normal renal function: serum creatinine ≤ 1.2 mg/dL.
• No severe or recurrent liver disease, and AST or ALT ≤ 3× the upper limit of normal.
• Able to communicate in Thai, complete the questionnaire, and provide written informed consent (no restriction on race or nationality).

Exclusion criteria

• Incomplete medical record.
• Use of any analgesic medications within 24 hours preoperatively.
• Receipt of any postoperative analgesic other than morphine during the first 24 hours after surgery.
• Withdrawal from the study.
• Adverse reaction after administration of the study drug.
• Concomitant surgery involving other organs (e.g., ovary or lymph nodes).