Fluid Therapy Flashcards
What % of an animal’s body consists of water?
60-70%.
What portion of total body water (TBW) is intracellular?
2/3.
What portion of total body water (TBW) is extracellular?
1/3 (4% in the blood or lymph vessels and 16% interstitial fluid).
How is interstitial fluid created?
By ultrafiltration.
What is ultrafiltration?
Where pressure in the capillaries forces small molecules out of the capillaries, while large molecules stay inside the capillaries.
What is interstitial fluid similar to?
Plasma, w/o proteins or RBCs.
What is the purpose of extracellular fluid?
To bathe cells, supply oxygen to the cells, and provide nutrients to the cells.
What is edema?
Abnormal excess accumulation of fluid in tissue.
What is pulmonary edema?
Abnormal excess accumulation of fluid in the lungs.
What is cutaneous/pitting cutaneous edema?
Abnormal excess accumulation of fluid under the skin that has little pits in it when pushed on.
What is edema a common sign of?
The abnormal movement of fluid from the vascular to interstitial space.
What is diffusion?
The movement of molecules from high concentration to low concentration along a concentration gradient until equilibrium is reached.
ex: Opposite of osmosis.
What 3 factors determine the ability of a molecule to pass through the cell membrane?
- Molecular charge (Charged molecules require a special pore/channel to pass through a cell membrane).
- Molecular size (The larger the molecule, the more difficult it is for it to pass through the cell membrane).
- Lipid solubility (Lipid soluble molecules will more easily pass through the cell membrane).
What is osmosis?
The PASSIVE movement of water through a semipermeable membrane from a dilute solution to a more concentrated one (Higher solvent to lower solvent or Lower solute to higher solute) until equilibrium is achieved.
*Opposite of diffusion.
What is osmotic pressure?
The force of water moving from one side to the other.
What are the characteristics of isotonic fluid?
- Osmolality comparable to that of normal blood.
- ECF has the same concentration of dissolved substances as intracellular fluid.
What are the characteristics of hypotonic fluid?
- Osmolality is less than that of normal blood.
- Cytoplasm of the cell is more concentrated than the ECF.
- Water flows into the cell and causes it swell and possibly lyse.
ex: 0.45% NaCl.
What are the characteristics of hypertonic fluid?
- Osmolality is greater than that of blood.
- ECF is more concentrated than the cytoplasm.
- Water shifts into the extracellular space, causing the cell to shrink and become shriveled. Could possibly crenate.
ex: Hypertonic saline (7% NaCl).
How many mL of water is lost in urine daily?
20 mL/kg.
How many mL of water is lost in feces daily?
10-20 mL/kg.