Effect of 6% hydroxyethyl starch pre-administration for reduction of pain on propofol injection: A placebo-controlled randomised study

BACKGROUND AND AIMS: Colloids modify the vascular endothelium and prevent contact activation of various substances. Pre-administration of colloids may prevent contact activation of vascular endothelium by propofol. The objective of this study was to evaluate the effect of 6% hydroxyethyl starch (HES) 130/0.4 pre-administration on propofol injection pain. METHODS: Adult patients of the American Society of Anesthesiologists physical status I and II patients, 18-65 years old, of either gender and undergoing elective surgery were randomised into two groups. 100 mL bolus of HES or 0.9% normal saline (NS) was administered over three to five minutes through an 18 G cannula placed in the hand or forearm vein, followed by induction with 1% propofol premixed with 2% lidocaine. Pain during propofol injection was assessed every 10 seconds before the loss of verbal contact as 0- no pain; 1- mild pain evident only on questioning after 10 seconds without any obvious discomfort; 2-moderate pain self-reported by patients within 10 seconds with some discomfort; and 3- severe pain accompanied by withdrawing of hand, and behavioural signs. RESULTS: 126 patients completed the study. Overall incidence of pain was significantly higher in the NS group vs HES group (53% vs 28%; P = 0.004; relative risk 1.54, 95% confidence interval 1.13-2.09). Incidence of severe (8% vs 0%) and moderate pain (16% vs 5%) was higher in the NS group, while the incidence of mild pain was comparable (29% vs 23%; NS vs HES). A significant difference was seen in the severity of pain between the groups (P = 0.002). CONCLUSION: Pre-administration of 100 mL bolus of 6% HES 130/0.4 significantly reduced propofol injection pain.