LIDOCAINE 3.0

Propofol can cause pain on injection.
This can be mitigated by using a large-bore cannula, cannulating a large peripheral vein, slow injection...and admixing lidocaine to the preparation or pretreatment of the bolus with IV lidocaine.
Most people can tolerate this pain but...kids?!
How does this mitigating effect work?
No-one knows...

Does the pretreatment with lidocaine work like a Bier's block - even though there is no venous occlusion?

or

Does Lidocaine work as a LA effect on the vessel wall at injection?...surely this is too quick...

But it does work...

And now this Cochrane review for once demonstrates a big effect of this intervention with a high level of evidence.
Interestingly NO difference was demonstrated between the admixture and pre-treatment!
[url=https://servimg.com/view/19522798/5][img]https://i.servimg.com/u/f35/19/52/27/98/screen10.png[/img][/url]
For kids : probably best to avoid too many syringes.
How much? - 1-2 ml
Concentration? - 1% mainly but also 2%...

BUT

Historically (theoretical) concerns : (2003)

Physicochemical problems with the admixture involving dose and time - dependant increases in oil-droplet diameter in emulsion.
Mixture is unstable over time and MAY cause PE, depending on the dose of lidocaine.

Study lives [url=http://www.ncbi.nlm.nih.gov/pubmed/14633535]here[/url]