Most IV fluids are isotonic, meaning, they have the same concentration of solutes as blood plasma.

What happens if IV is hypertonic?

* When hypertonic fluids are infused, water moves out of the cells in an attempt to dilute the infusate, shrinking the cells. When they shrink at the I.V. infusion site, the basement membrane of the vein's lining is exposed, creating the risk of phlebitis and infiltration as described above for hypotonic infusions.

When would you use a hypertonic solution?

Examples of when hypertonic solutions are used include to replace electrolytes (as in hyponatremia), to treat hypotonic dehydration, and to treat certain types of shock. Solutions with a lower concentration of solutes than isotonic solutions are hypotonic.