Fluid Status/Diuretics Flashcards
When people say fluid what are they talking about?
Blood, plasma, water
How does fluid enter the body?
PG, NG Tube, IV, drinking, absorption
How does fluid leave the body?
Urine, Sweat, breathing (insensible loss), bleeding, vomiting, defecation
Describe how fluid is distributed in the body?
40% solid, 60% Fluid
2/3 ICF, 1/3 ECF (20% plasma, 80% Interstitial fluid)
What are the standards we must consider when looking at TBW?
1L of water = 1 kg
Values are based on the 70 kg man
What is tonicity?
Concentration of a solution compared to another solution
What is osmole?
Number of osmotically active particles in a solution
What is osmolality?
Osmoses/kg of water
What is osmolarity?
Osmoles/Liter of solution
What components are not included in the TBW and osmolarity of body fluids?
WBC, RBC, platelets
What are extracellular electrolytes?
Cations: Na+, Ca2+
Anions: Cl-, HCO3-
What are the intracellular electrolytes?
Cations: K+, Mg2+
Anions: PO4^3-, proteins
What is the physiological osmolarity?
280 mOsm/L
What is the difference between filtration and reabsorption?
F: Fluid exits the arterial capillary due to capillary hydrostatic pressure
R: Fluid moves in the venous capillary driven by colloid osmotic pressure
How do we maintain fluid status?
- ADH
- RAAS (retain Na+ and water)
- Natriuretic peptides (lose Na+ and water)
- Osmoreceptors in the hypothalamus
- Proteins
Water follows the highest concentration of solute
What are the types of fluid balance states?
- Hypervolemia
- Euvolemia
- Hypovolemia
What are the daily fluid requirements?
1st 10 kg/ → 100mL/kg
2nd 10 kg → 50 mL/kg
Weight over 20 kg → 20 mL/kg
What are the hourly fluid requirements?
1st 10 kg/ → 4 mL/kg
2nd 10 kg → 2 mL/kg
Weight over 20 kg → 1 mL/kg
What is the clinically utilized fluid requirement?
25-30 mL/kg
What is progressions of hypovolemia?
Euvolemic → GI and intraabdominal → lack of intake → skin → kidneys → insensible losses → dehydration
What are the signs and symptoms of hypovolemia?
- Fatigue
- Thirst
- Dry mucous membraneis
- Low UO
- Muscle cramps
- Lightheadedness
- DZ
- Hypotension
- Poor skin turgor
- Sunken eyes
What are the lab findings of hypovolemia?
≥295 mOsm/kg
BUN/sCr >10:1
Low urine Na+ concentration
High urine osmolality