How to integrate nodejs in codeigniter

I want to integrate node.js in codeigniter framework but I am having confusion that how to execute node.js in codeigniter.I have knowledge about codeigniter but nodeJS is still quite new for me.
How do I integrate nodejs in my existing website which is in codeigniter?
Any kind of help would be highly appreciated.

You need to be more specific on what you want to do. Both are server side processors, and they aren't built to co-exist. You generally use one of them.