To force yourself to stay awake,
without any alertness aid, in order to perform
required duties/responsibilities, even though you had minimal (if any) sleep
the night before.
He insisted he would scrudge through his work day without any caffeine even though he only had 3 hours of sleep
the night before. He was
looking forward to his evening nap before another
long night, minimal sleep, and another scrudging day tomorrow.