Question about Defribrillation

I am trying to understand the requirements for Debribrillation.
I know that for CPR it is extremely important to have a flat surface available to administer CPR. But is a flat surface necessary to administer Defribrillation?

Thanks.

[ed34]

Yes, defibrillation is normally in many times in conjunction with cpr. The patient should be laying down to enable the body to easier equalise blood pressure and the body will jerk when receiving a shock, making it a danger to you and the patient if not laying down. A patient in a chair receiving a shock could suddenly be out of the chair laying over you, stopping your heart.
I have to laugh when I watch Defibs being used in films or tv hospital shows. Have you seen the position they put the paddles in? always right next to each other in the middle of the chest. Current wouldnt pass through the heart, it would just go through the skin, burning it, and into the other paddle.
Here's an interesting report :)  

http://www.bmj.com/cgi/content/full/322/7299/1393