Hemodynamic Effects of Intravenous Paracetamol in Patients Undergoing Emergency Laparotomy

Hemodynamic Effects of Intravenous Paracetamol in Patients Undergoing Emergency Laparotomy: a Randomized Controlled Trial

Emergency laparotomy is a high-risk procedure often performed in patients with severe physiological derangements due to sepsis, making perioperative management challenging. Although multimodal analgesia is essential, options are often limited by factors such as hemodynamic instability, renal dysfunction, and coagulopathy. Intravenous paracetamol is commonly recommended for perioperative analgesia because of its opioid-sparing effect, but evidence suggests it may cause hypotension through peripheral vasodilation, particularly in critically ill patients. Most data on this effect come from observational studies, and evidence regarding its intraoperative hemodynamic impact remains limited.

Study Overview

• Status: Recruiting
• Conditions: Hypotension Drug-Induced; Paracetamol; Emergency Surgery
• Intervention / Treatment: Drug: Paracetamol (acetaminophen); Other: Placebo Control

Detailed Description

Preoperative fluid administration will be guided by stroke volume change after passive leg raising maneuver Patients will receive propofol 2 mg/kg and fentanyl 1 µg/kg for induction, followed by succinylcholine 1 mg/kg for intubation. Anesthesia will be maintained with isoflurane (end-tidal 1.2%) and atracurium 0.5 mg/kg, then 0.1 mg/kg every 20 minutes.

After administration of the study drug (paracetamol or placebo), Heart rate and blood pressure will be monitored at 2 min intervals for 20 min. If patients developed hypotension (mean arterial pressure [MAP] ≤ 70% of the baseline reading and/or <65 mmHg), a 5-mcg bolus of norepinephrine will be given. The norepinephrine bolus will be repeated if mean arterial pressure was not restored within 2 min.

• Study Type: Interventional
• Enrollment (Estimated): 90
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Maha Mostafa; Phone Number: +201000365115; Email: maha.mostafa@cu.edu.eg

Study Locations

• Egypt
  • Cairo Governorate
    • Cairo, Cairo Governorate, Egypt
      • Recruiting
      • Cairo University
      • Contact: ahmed Hasanin, Lecturer; Phone Number: +2010095076954; Email: ahmedmohamedhasanin@gmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Adult patients, ASA I-III undergoing emergency laparotomy

Exclusion Criteria:

• Severe cardiac morbidities (impaired contractility with ejection fraction < 40%, heart block, arrhythmias, tight valvular lesions)
• Hemodynamically unstable patients (defined as patients with MAP < 65 mmHg or need vasopressor to maintain MAP>65 mmHg).
• Patients with high shock index (heart rate / systolic blood pressure >1)
• Pregnant or lactating women,
• Allergy of any of the study drugs

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Control group	Other: Placebo Control; Patients will receive 100 mL saline 0.9% (prepared by withdrawing 100 mL of saline 0.9% into two 50 mL syringes). The dose will be infused at a rate of 600 mL/h.
Active Comparator: Paracetamol group	Drug: Paracetamol (acetaminophen); Patients will receive 1 g intravenous paracetamol (prepared by withdrawing 100 mL of paracetamol into two 50 mL syringes). The drug will be infused at a rate of 600 mL/h to be completed over a period of 10 minutes

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mean arterial pressure	noninvasive mean arterial pressure	10 minutes after infusion of the study drug

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
drug induced hypotension	mean arterial pressure ≤ 70% of the baseline reading and/or <65 mmHg	from drug administration until 30 minutes after drug administration
Heart rate		from drug administration until 30 minutes after drug administration
mean arterial pressure		from drug administration until 30 minutes after drug administration

Collaborators and Investigators

• Sponsor: Cairo University

Study record dates

Study Major Dates

• Study Start (Actual): March 18, 2026
• Primary Completion (Estimated): September 1, 2026
• Study Completion (Estimated): September 1, 2026

Study Registration Dates

• First Submitted: March 8, 2026
• First Submitted That Met QC Criteria: March 8, 2026
• First Posted (Actual): March 12, 2026

Study Record Updates

• Last Update Posted (Actual): March 20, 2026
• Last Update Submitted That Met QC Criteria: March 18, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Hypotension; Organic Chemicals; Anilides; Amides; Aniline Compounds; Amines; Acetanilides; Acetaminophen
• Other Study ID Numbers: MD-404-2025

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: data related to this research will be available from the PI upon reasonable request

Drug and device information, study documents

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