Use coconut water as a substitute for plasma or IV fluid?

There are stories from WW2 in the Pacific that American and British medics sometimes used coconut water when IV bags or plasma were scarce.

Coconut water is similar to blood plasma, but instead of being high sodium and low in potassium, it's the opposite. So it was better than nothing, but not ideal. It'd be easy enough to blend coconut water with something else to get the right concentrations. 

Coconut water IV plus some salt tablets would work for patients able to swallow. A low potassium diet would also help until the patient recovers.