After reading these links, looks like coconut water has been used with some success. I drink it myself as a cold beverage from time to time. Easily found at my local health food stores. Good source of electrolytes and potable water.

Hmmm, I wonder what the risk of infection from those cartons of coconut water would be if used as an IV straight from the box? I believe they are pasteurized. I know, that's not the same thing as saying something is "sterile" but we're talking worst case scenario here.

However, sounds like a rather odd situation to be--had the equipment to administer an IV but only coconut water available? Sounds like wartime, like maybe a Sarajevo scenario.

Another way to get this into your system might be the good ol' enema. Slower but safer than injecting it directly, if utmost speed isn't critical.