Comparison of the Effects of Two Different Doses of Remifentanil Infusion on Intraoperative Blood Loss and Hemodynamic Parameters in Patients Undergoing Femur Surgery

To compare the effects of two different doses of remifentanil infusion (0.25 and 0.5 mcg/kg/min) on intraoperative blood loss and hemodynamic changes in patients undergoing femur surgery.

A randomized, double-blind, parallel-group, controlled clinical trial with 1:1 allocation ratio on 60 patients undergoing femur surgery. Random Allocation software was used for randomization.

The study will be conducted at Shahid Mohammadi Hospital in Bandar Abbas. After obtaining informed consent, 60 patients will be randomly allocated. Hemodynamic parameters will be recorded every 15 minutes. For postoperative pain with a visual analogue scale greater than 3, pethidine will be administered.

Patients aged 18 to 70 years who are candidates for elective femur surgery under general anesthesia with ASA class I and II will be included. Exclusion criteria include severe cardiovascular diseases, remifentanil allergy, lack of informed consent, and need for additional morphine during surgery.

Group one receives remifentanil 0.25 mcg/kg/min and group two receives 0.5 mcg/kg/min. All patients receive identical anesthesia induction with midazolam, fentanyl, propofol, and atracurium plus morphine sulfate 0.1 mg/kg.

Primary outcomes include intraoperative blood loss and hemodynamic parameters (systolic blood pressure, diastolic blood pressure, mean arterial pressure, and heart rate). Secondary outcomes include blood transfusion requirements, fluid consumption, surgeon satisfaction, postoperative pain intensity, analgesic requirements, and urine output.

In this clinical trial, simple block randomization with individual randomization units will be used. Patients aged 18 to 70 years with ASA class I and II who are candidates for femur surgery under general anesthesia will be placed in blocks of 4 and 6 individuals and assigned in a 1:1 ratio to two groups: low-dose (0.25 mcg/kg/min) and high-dose (0.5 mcg/kg/min) remifentanil. Random Allocation Software will be used to generate the random sequence, with sealed opaque envelopes as a backup method. The seed number will be extracted from the system time at execution and recorded for reproducibility. Allocation concealment will be ensured through a central system that does not reveal allocation until complete patient information is registered, unique coding for each patient, separation of research team responsibilities (separation of enrollment personnel from allocation personnel), emergency envelopes for urgent cases, restricted access control to the randomization sequence, and complete process documentation to minimize selection bias.

This is a double-blind clinical trial in which patients, surgeons, surgical team, and outcome assessors will be unaware of the remifentanil dose administered (0.25 or 0.5 μg/kg/min) and the patient's group allocation. Drug preparation and administration will be performed by an anesthesiologist who is not involved in outcome assessment, and syringes containing remifentanil will be prepared with coded labels (A or B) without indicating the actual dose. Allocation codes will be kept in sealed envelopes and will not be opened until the end of the study and completion of data analysis, except in emergency situations. Data collection will be performed by a nurse or research assistant who is blinded to patient grouping, and only the anesthesiologist responsible for drug preparation and the person responsible for randomization (who are not involved in enrollment and outcome assessment) will be aware of the allocation.

Still undecided - no release schedule yet.