41. Patient, age 24, has been suffering from food poisoning with vomiting and diarrhea. He has been drinking a lot of plain water, not Gaitoraid or Pedialite. Skin and mucous membranes are dry, and he's complaining of a headache. Heart rate is normal, but he has high BP=200/120.
Do you give an iv solution that is hyper, hypo, or isotonic? Why?