Pain assessment in fentanyl-propofol combination: two dosage levels

Abstract

Background. In the field of intravenous anesthesia, propofol is widely utilized as an induction agent. However, Propofol injection pain is a frequent adverse event that may result in discomfort for patients. Various strategies have been investigated to prevent or alleviate this pain, considering the presence of opioid receptors in the primary afferent nerve endings of peripheral tissues, which suggests a potential role of opioids in mitigating propofol-induced pain. Fentanyl, a short-acting pure opioid agonist commonly used for systemic analgesia during intraoperative and postoperative periods, has been found to possess peripherally mediated analgesic properties within its clinical dosage range. Therefore, the objective of this study was to evaluate the efficacy of a low dose of fentanyl in the fentanyl-propofol combination for reducing propofol injection pain.The objective of our study was to evaluate and compare the efficacy of two distinct doses of fentanyl in mitigating the pain associated with propofol injection.Materials and methods. The study enrolled 90 patients classified as ASA I–II who were scheduled for elective surgery. The study spanned over 4 months, from November 2022 to April 2023, and included patients aged 19 to 65 years. Patients were divided into three groups, each comprising 30 patients. The control group received only 5 ml (50 mg) of propofol. The group M1 received only 5 ml of a mixture of fentanyl and propofol, prepared with 20 ml (200 mg) of propofol and 2 ml (100 μg) of fentanyl, while the group M2 received only 5 ml of a mixture of fentanyl and propofol, prepared with 20 ml (200 mg) of propofol and 4 ml (200 μg) of fentanyl, at an injection speed of 0.5 ml/s. After 10 seconds of medication, patients were asked a standard question about the comfort of the injection, and a verbal rating scale (VRS) was used to assess propofol injection pain. Anesthesia induction was then continued following standard protocols. Statistical significance was set at p < 0.05 for all analyses.Results. The three groups were found to be similar in terms of patient characteristics. In the control group, the incidence of severe pain upon propofol injection was 46.7%, whereas it was 0% in both groups M1 and M2 (p < 0.05).Conclusion. The combination of fentanyl and propofol has been shown to effectively reduce the incidence of propofol injection pain. Interestingly, in this study, no significant difference was observed between the two different doses of fentanyl used in the mixture. This suggests that a low dose of fentanyl may be sufficient in achieving a pain-free environment during propofol induction, thereby offering a cost-effective approach in clinical practice.