G-tube- Gastric- goes to the stomach. IE A Nice little bucket that can hold fluids, if the patient is not digesting foods well. So, do all standard care check residuals when tube feed is running, keep head of bed at 30 degrees etc. If there is no tube feed running you DONT need to check a residual...WHY? what are you checking a residual for?.....TO SEE IF THEY ARE TOLERATING THE FEED.
Now if you were going to start a new feed on a person you need a residual as a base line.
J-tube goes past the pyloric schinctor (sp) into the jejunum- small intestine ie hallow tube. there is no little bucket to trap fluids. There should be no residual there. We do not check residuals on J-tubes.
As for free water. We do give free water, it is a nursing intervention, like offering someone a drink. The only thing is in an acute setting we look at how much IV fluids they are getting. If they are only at KVO we give free water, if they have more fluids per hour is it not as important.
One would also have to consider the particular illnesess of the individual. I have had the big CHF'ers that 100 cc of fluid will tip them over, but if there heart is that bad we generally are privy to that knowledge. As far as their lytes go giving a lot of free water can impact their sodium levels--so can many other things, but allowing someone to be dry has many more consequences to the patient.
I think bacicly the answer to your question is look at the patient and determine what he or she needs.