Effect of 6% hydroxyethyl starch (130/0.4) for prevention of pain on propofol injection: randomized control trial

Propofol is an excellent induction agent for anaesthesia, However, pain on propofol injection is an unpleasant experience for most patients undergoing surgery. Many agents including local anaesthetics, opioids, antiemetics, hypnotics have all been tried to mitigate the pain on propofol injection with varying degrees of success. Colloids are usually given to patients undergoing surgery to maintain the intravascular volume and adequate tissue perfusion. Preloading with colloids is also a common practice to prevent hypotension during induction of anaesthesia. There is evidence that colloids prevent the adhesion of platelets and other molecules to venous endothelium by coating the veins. Since the main mechanism of pain is irritation of veins due to release of kinins by direct activation of venous endothelium by the phenol moiety of propofol, it would be useful to see if the pre-administration of colloids would coat the venous endothelium and prevent the contact activation of the venous endothelium by propofol and thus, prevent the pain on propofol injection.