How come sometimes it takes longer for a patent to wake up from a operation then before?

Question: How come sometimes it takes longer for a patent to wake up from a operation then before?
- Keywords:
  operation,
  patient,
  sleep
Asked by petsrcool to Christina on 23 Jun 2013.
- Christina Pagel answered on 23 Jun 2013:
  
  When you have an operation, the doctors give you a general anaesthetic to knock you out. How much they give you is carefully calculated by adjusting for things like your weight, your height, how much exercise you do, how much acohol you drink and how much tea and coffee you drink…all these things (and others) affect how well your brain responds to the anaesthetic…
  
  While doctor’s are really good at doing this there is always a bit of uncertainty, so having a drink of coffee shortly before an operation or having had a heavy night drinking a couple of days before can affect how long the drugs work for – this is why every time you have an operation how long it takes you to wake up is likely to be different!
  
  Also, you need more anaeasthetic for longer operations and it takes longer to wake up after lots of anaesthetic than a little… so how long your operation took is also going to make a difference.

Question: How come sometimes it takes longer for a patent to wake up from a operation then before?