Question: is d5 1/2 normal saline isotonic?
Answer: Notice that sodium plays a bigger part in determining your osmolality than glucose. That's why D5 1⁄2 NS is not an isotonic solution. As such, D5 1⁄2 NS is NOT appropriate for most medical patients who are hypovolemic. Such patients need isotonic fluids (normal saline or Lactated Ringers).