Medicine
Intravenous Fluid Composition and Tonicity in Perioperative Care
Quick fact
After infusing 1 liter of isotonic crystalloid, only about 250 mL remains in the bloodstream—the rest leaks into the interstitial space within 30 minutes.
Why this is interesting
You've just given a patient 2 liters of IV fluid, but where does that water actually go? And why might the simple choice of bag—saline vs. balanced crystalloid—subtly alter their acid-base balance?