“The influence of female body mass index, menstrual cycle phase and age on propofol injection pain”

Abstract

Background: Eliminating propofol injection pain (PIP) should be multimodal, including pharmacological and non-pharmacological interventions. Understanding risk factors–body mass index, menstrual cycle phase and age for example–leading to increased pain sensitivity will identify patients at most risk for PIP, permitting effective treatment strategies to be initiated at an early stage. Objective: Our goal is to determine occurrence and severity of propofol injection pain among female patients, whether they are obese or non-obese, during different menstrual cycle phases. Methods: Design: A prospective observational study. Setting: Single university teaching hospital’s operating rooms. Patients: 84 female undergoing surgeries under general anesthesia, classified as American Society of Anesthesiologists (ASA) physical status I–II, between 18 and 65 years of age were enrolled. Interventions: We evaluated propofol injection pain using visual analogue scale (VAS) during induction of general anesthesia. Main outcome measure: The relation between propofol induced peripheral venous pain and female body mass index, menstrual cycle phase and age. Results: 71.4% of patients experienced PIP. Of those patients who experienced PIP; 40.5% (34/84 patients) had moderate to severe pain. Age <35 years was the only independent predictor of moderate/severe PIP (sensitivity 62%, specificity 78%). After adjustment for age category, there was no statistically significant association between occurrence of moderate/severe PIP and obesity or menstruation. Conclusion: Propofol injection pain prophylactic measures should be considered in young females <35 years as they may be more prone to moderate/severe PIP. Trial Registration: NCT04078087.