Sleep is such a critical part of everyone's health and without it our quality of life deteriorates quite rapidly (as many of us kn0w). Our body does a great job of telling us when we are hungry, thirsty, or injured. It also signals quite clearly when we need to sleep.
So why do so many of us (me included some times) battle that signal, sometimes with the help of caffeine or high-caffeine products? I do understand doing that to survive the work day, or the working of different hours, if you are very tired and have no real choice BUT doing this to excess is only going to give you short term gain for long term pain. Yes, you will go for longer than you otherwise could but this is a battle you will never win and ultimately your body will be negatively impacted by this "abuse" and you will pay the price.
Don't battle the sleep signal too long - you will be sorry you did and in the long run you will be happier and much more productive if you have had your needed sleep.