David: A February 2016 addition to the nearly 200 reviews from the Cochrane Anaesthesia, Critical and Emergency Care Group examines the evidence on lidocaine as a way to reduce the pain from using propofol to induce anaesthesia. Hayley Hassan, from the Cochrane Central Executive Team, describes the need for the review and its findings in this podcast, on behalf of the review authors.

Hayley: Propofol is a very popular anaesthetic. It acts quickly, gives predictable levels of sedation and has a short recovery time. However, it has one common undesirable effect: it can be very painful when it is injected. One way to try to ease this pain is to use a drug called lidocaine and although there have been reviews showing that this can reduce the incidence and severity of propofol-induced pain, none of them have focused on lidocaine for preventing high-intensity pain. Our review fills this gap by assessing the efficacy and adverse effects of lidocaine in preventing high-intensity pain caused by propofol injection. We also wanted to look at patient satisfaction but none of the 87 randomised trials we found reported on this.
However, we could use 84 of the studies, with nearly ten and a half thousand patients, in our quantitative analyses of other outcomes. These participants ranged in age from 13 to 89 years, and were having elective surgery for non-life threatening conditions. 
The results are convincing. Intravenous lidocaine, either when it was mixed lidocaine with the propofol or given before it, reduced both the incidence and the level of pain, at both high and low doses of lidocaine. However, low-dose lidocaine pretreatment did appear to be the least effective form. Adverse effects, such as thrombophlebitis which is an inflammation of the vein at the injection site, were reported in only two studies, and were rare and no more common in the lidocaine than the control groups.
In summary, the overall quality of the evidence was high, with a large beneficial effect. The currently available data from randomized trials confirm that lidocaine mixed with propofol and pretreatment with lidocaine are both effective in reducing pain on propofol injection, with no significant differences in the effect between these two techniques.

David: If you would like to read more about the different techniques and the strength of the evidence supporting the use of lidocaine, visit Cochrane Library dot com where a simple search for 'Lidocaine and propofol-induced pain' will show you the review.