I have extensive experience with this sort of thing. I've been in the infantry in the Marine Corps for just over 10 years and when we do operations/training/etc. you only get sleep when you can. When we're not doing that sort of thing I still get up around 5 am every day just to feel normal and so I don't feel as if the whole day was wasted. The thing I realized over the years is that it's just sleep and you can get more of it later. I used to hate feeling tired but I figured that I have things to do and I just have to get over it and do what needs to be done. I can always sleep later. That being said, I have noticed with myself that to wake up feeling refreshed and energized I need about 6 hours of sleep. Any more than seven or any less than than four hours of sleep and I'm pretty groggy the next morning.

I believe that the "need" or want for sleep and being worried about the effects of too little sleep is what gets people worked up over it. I just demoted the importance of sleep and I feel much better the next day about not getting "enough" sleep. Every day we have scientists touting the importance of sleep and how it can have health effects, etc. While not disagreeing with them (obviously your body needs sleep) I think that more damage is done by poor stress management than lack of sleep. If you go to sleep stressed out you're not going to have a good nights rest and no matter how many hours of sleep you get you're not going to wake up feeling rested.

If I have many consecutive nights of 3-4 hours of sleep then I found that my body gets pretty used to only getting that much. If you only have the problem of 3-4 hours of sleep once a week I wouldn't worry about it and try to adjust for your "down" productiveness the next day. At least by admitting that you're going to be worthless to the world the next morning to yourself you can adjust for that in your work schedule and maybe even warn coworkers. Although, if you were my Marine/employee I'd expect more out of someone than to be totally thrown off track by one late night. ;)

Sorry for the rambling but I feel that sleep and the worry of not getting enough makes people over-emphasise sleep. Sort of like people that want to lose weight so they go on starvation diets, they all end up fascinated with food and think about it all day long due to hunger so they end up eating their pantries empty.