IV Fluids Review
💦 IV fluids – What the tonic?
✏️The human body is composed of 60% water 💦
-Two-thirds of it is available INTRAcellularly (space INside cells)
-One-third of it is stored EXTRAcellularly (EXTERNAL space in blood vessels and around cells)
⭐ There are different types of fluids with varying chemical compositions of salt and electrolytes that are designed to bring fluid into cells or keep fluid within the bloodstream.
🔑 Key Tips:
-Water flows where sodium (or particles) goes!
-Solutions want to have the same ratio or balance of solvents (water) to solute (particles such as salt)
-Water will flow from an area of low particles to an area of high particles
-Semi-permeable membranes allow water to pass through but not particles
⭐ First, think of the starting point as the space within blood vessels (or intravascular space) since IV fluids are infused directly into the bloodstream 🩸
⭐ ISOtonic fluids: “ISOlated in the vasculature”
-Equal amounts of water and particles so there is no movement between the compartments
-Water from IV fluids stay ISOlated in the vasculature – used in situations where there is fluid loss and replacement is needed (ex: hemorrhage, diarrhea, vomiting)
-Examples include: 0.9% sodium chloride (normal saline), dextrose 5% in water (D5W), lactated ringer (LR)
⭐ HypOtonic fluids: “Out of the vasculature”
-Low amounts of particles compared to water
-Water flows OUT of the vascular into the cells
-Used in situations where we have intracellular dehydration (ex: DKA, HHS)
-Examples include: 0.45% sodium chloride (1/2 normal saline), 2.5% dextrose in water
⭐ HypErtonic fluids: “Enter the vasculature”
-High amounts of particles compared to water
-Water ENTERS the highly concentrated vasculature from cells
-Used in situations where there are swollen cells (ex: cerebral edema) or hyponatremia
-Examples include: 3% sodium chloride (hypertonic saline), dextrose 10% in water (D10W)
