Using PDO with CodeIgniter

[eluser]MEM[/eluser]
I'm the most newbie you can get on frameworks, programming, oop, design patterns etc, so please, have patience.

Right now, without CI, I'm using PDO for my database interactions.
I have a singleton myPDOclass that extends PDO and then I have an AbstractDAOClass that use this myPDO singleton class. All my DAO classes then extend my abstract class, hence, all the classes are database connected.

I don't know if I can keep this structure using CI, however, I would be glad if I can use PDO.

I've googled PDO and CodeIgniter and I've found no relevant information so, I'm just asking if someone could give me a hand on this and tell me, if it's possible, and if it could be easy implemented.

Regards,
MEM