Fluid And Electrolytes Part 1 Flashcards
The body is always trying to achieve:
Homeostasis
Water uses in the body:
- Metabolic transport
- Transport
- Lubricant
- Insulator
- Body temperature
How are fluids lost?
- Kidney: Urine output of 1 mL/kg/hr
- Skin loss: sensible due to sweating and insensible due to fever, exercise, and burns.
- Lungs: 300 mL everyday, greater with increased RR.
- GI: Losses due to diarrhea or fistulas.
Factors affecting water balance:
- Age
- Sex/ Gender
- Body habitus
- Temperature
- Disease state
Approximately 60% of typical adults are fluid, how is this dispersed?
- Intracellular fluid (~40% of body weight/ 28 liters): ⅔ of body fluid, skeletal muscle mass.
- Extracellular fluid (~20% of body weight/14.5 liters):
- Intravascular (5% / 3.5 liters): Plasma, erythrocytes, leukocytes, thrombocytes.
- Interstitial (14% / 10 liters): Lymph
- Transcellular (1% / 1 liter): Cerebrospinal, pericardial, synovial.
Osmolarity:
Fewer particles =
Lower osmolarity
Osmolarity:
More particles =
Higher osmolarity
Normal serum osmolarity:
280-295 mOsm/kg
Osmolarity - Isotonic fluid:
Fluid with the same osmolarity.
Isotonic fluid examples:
0.9% NaCl and LR
Osmolarity - Hypotonic fluid:
Solutes are less concentrated than the cells.
Hypotonic fluid examples:
0.45% NaCl
Osmolarity- Hypertonic Fluid:
Solutes are more concentrated than the cells.
Hypertonic fluid examples:
3% NaCl
D5W is considered what kind of fluid?
Both Isotonic and hypotonic crystalloid fluid.
Osmosis definition:
Water moves from an area of low solute concentration to an area of high solute concentration.
During osmosis water moves across a ______ _______.
Semipermeable membrane.
Hydrostatic Pressure:
Exerted on walls of blood vessels.
Blood pressure generated by heart contractions.
Osmotic pressure:
Exerted by proteins in plasma.
Proteins (albumin) in plasma attract water, pulling from the tissue spaces into the vascular space.
The direction of fluid movement depends on differences in:
Hydrostatic and osmotic pressure.