Effect of 6% Hydroxyethyl Starch Pre Administration for Reduction of Pain on Propofol Injection: A Placebo-Controlled Randomised Study

Abstract

Introduction:
Pain on intravenous propofol injection is a common and distressing complication, affecting up to 90% of patients and negatively impacting the induction experience. While various pharmacological agents have been used to mitigate this pain, the role of colloid preloading such as 6% hydroxyethyl starch (HES) has not been extensively studied. This study aimed to evaluate the efficacy of 6% HES in reducing the incidence and severity of pain during propofol injection.

Materials and Method:
This was a prospective, randomized, placebo-controlled, double-blind study conducted from October 2023 to June 2024, involving 126 adult patients (ASA I/II) undergoing elective surgery under general anaesthesia. Patients were randomly allocated into two groups: Group A (n=64) received 100 mL of 6% HES, and Group B (n=62) received 100 mL of normal saline over 3–5 minutes before induction. Pain on propofol injection (1% propofol mixed with 1 mL of 2% lidocaine) was assessed every 10 seconds before loss of verbal contact using a four-point verbal response scale.

Results:
The incidence of pain was significantly lower in the HES group (28%) compared to the saline group (53%) (p = 0.004). Severe pain occurred in 0% of HES patients versus 8% in the saline group, and moderate pain in 5% vs 16%, respectively. The difference in pain severity was statistically significant (p = 0.002), with a large effect size (Cohen’s d = 0.73) and a number needed to treat (NNT) of 4.

Conclusion:
Pre-administration of 6% HES effectively reduces both the incidence and severity of pain on propofol injection and may serve as a safe, simple, and clinically useful strategy.