💦 ⁠ 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) ⁠