Efficacy of 6% Hydroxyethyl Starch and 2% Lidocaine in Reducing the Pain of Propofol Injection: A randomised, placebo-controlled trial.

Objectives: Propofol administration is associated with pain, mediated by the activation of vascular endothelium. Hydroxyethyl starch (HES) inhibits endothelial membrane activation by various nociceptive substances. Thus, this study hypothesised that pre-administration of HES can reduce pain on propofol administration. This study aimed to compare the proportion of patients with no pain on propofol administration and to compare the severity of pain and any change in pre- and post-induction haemodynamic variables.

Methods: This prospective, randomised, placebo-controlled clinical trial was conducted at Chirayu Medical College & Hospital, Bhopal, India, between August 2023 and December 2023 and included patients undergoing elective surgery under general anaesthesia. Patients were randomly assigned to 3 groups to receive either 100 mL of 6% HES followed by propofol (Group HES), 100 mL normal saline (NS) followed by propofol premixed with 2% lidocaine (Group L) or 100 mL NS followed by propofol induction (Group P).

Results: A total of 339 patients were included. The proportion of patients with no pain on propofol injection was significantly higher in the HES group (n = 75) than in the lignocaine (n = 33) and placebo (n = 13) groups (P <0.0001 each). The median pain scores were 0 (interquartile range [IQR]: 0-1), 1 (IQR: 0-1) and 2 (IQR: 2-3) in the HES, lignocaine and placebo groups, respectively. The proportion of patients with moderate (n = 44) and severe (n = 48) pain scores was significantly higher in the placebo group than in the HES and lignocaine groups (P <0.0001 each).

Conclusion: The proportion of patients experiencing pain on propofol injection was found to be significantly less with the pre-administration of 100 mL 6% HES compared to the pre-administration of lidocaine.