š¦ ā IV fluids – What the tonic?
āļøThe human body is composed of 60% water š¦ ā
-Two-thirds of it is available INTRAcellularly (space INside cells)ā
-One-third of it is stored EXTRAcellularly (EXTERNAL space in blood vessels and around cells)ā
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ā 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.ā
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š Key Tips:ā
-Water flows where sodium (or particles) goes!ā
-Solutions want to have the same ratio or balance of solvents (water) to solute (particles such as salt)ā
-Water will flow from an area of low particles to an area of high particlesā
-Semi-permeable membranes allow water to pass through but not particlesā
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ā First, think of the starting point as the space within blood vessels (or intravascular space) since IV fluids are infused directly into the bloodstream š©øā
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ā ISOtonic fluids: āISOlated in the vasculatureāā
-Equal amounts of water and particles so there is no movement between the compartmentsā
-Water from IV fluids stay ISOlated in the vasculature ā used in situations where there is fluid loss and replacement is needed (ex: hemorrhage, diarrhea, vomiting)ā
-Examples include: 0.9% sodium chloride (normal saline), dextrose 5% in water (D5W), lactated ringer (LR)ā
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ā HypOtonic fluids: āOut of the vasculatureāā
-Low amounts of particles compared to waterā
-Water flows OUT of the vascular into the cellsā
-Used in situations where we have intracellular dehydration (ex: DKA, HHS)ā
-Examples include: 0.45% sodium chloride (1/2 normal saline), 2.5% dextrose in water ā
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ā HypErtonic fluids: āEnter the vasculatureāā
-High amounts of particles compared to water ā
-Water ENTERS the highly concentrated vasculature from cellsā
-Used in situations where there are swollen cells (ex: cerebral edema) or hyponatremiaā
-Examples include: 3% sodium chloride (hypertonic saline), dextrose 10% in water (D10W) ā
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