1. Fluid and Electrolyte Balance
KNH 413
Maintaining homeostasis: 1. water/fluid balance, 2. electrolyte balance

3. Plasma: high % Na, l, Bicarb, Pro
Interstitial: tissues
Intracellular: % K, NaP
cc’s of fluid to maintain the balance between these 3
-Food sources: 700 cc’s of fluid (iceberg lettuce, fruits, etc)
-Bi-product of processing/metabolism the food: 200 cc’s

4. Calculating fluid needs of an individual: per kilo
10 kg baby: mL/kg= ~1,000 cc’s
30 cc’s per oz., meaning 33 oz of formula/day (divide by 8, so 4 oz per feeding)
40-60 for an adolescent because they’re probably more active whereas adults generally tend to be less active, so they have a lower fluid need

5. Body Solutes Types of solutes Electrolytes Other molecules
Sodium, potassium, calcium, magnesium, chloride, bicarbonate, phosphate, sulphate
Ions dissociate to form charged particles
Other molecules
Glucose, protein, urea, lactate, organic acids—keep these in a stable range!
Hyperglycemic patient: excess sugar in the blood, where it is pulling fluids out, and fluid status would therefore not be balanced
Remain stable
Intracellular: K, Mg, P
Extracellular: Na, Ca, Cl, Bicarb

6. Body Solutes Distribution of solutes
Sum of cations (positive charge) must be equal to sum of anions (negative charge) within a given compartment
Movement of solutes influenced/measured by:
Molecular size
Electrical charge of the molecule
Hydrostatic pressure (pressure exerted by fluid due to the force of gravity)
Method of solute transport (what’s going on with the proteins?)
Fluid and acid/base balance: Maintaining fluid balance as removing waste between blood and tissue

8. Plasma: 5% water
Interstitial: 15% water
Intracellular: 40% water
Total= 60% of water found in these areas
Look at AI b/c no RDA
Potassium: after 6 months, infants need 3,000 mg K per day (raisons, potatoes, beans, spinach, bananas)
Adults need 4,500 g K per day
Breastfeeding mothers need to maintain K for themselves and their infant, RD would need to work with the individual to see what they prefer as their high source of K. Supplement may be used, yet the concern would be K toxicity so levels would need to be closely monitored (perhaps half supplement during meal)

9. SHOULD JUST KNOW!

10. Regulation of Fluid and Electrolytes
Osmotic and hydrostatic pressure—keep in balance
Thirst—triggered by hypothalamus and increased with fluid intake (preventative hydration)
Renal—increases amount of fluids running through the kidney
Hormonal influence – RAAS (influencing kidneys to retain sodium and pull fluid back into the blood)
Electrolyte regulation—want to keep all of these in balance

11. Regulation of Fluid and Electrolytes
Thirst
Renal function
Renin-Angiotension-Aldosterone System
RAAS

13. Glomerular Filtration Rate

14. High blood Ca, body inhibits vitamin D uptake
Osteoporosis needs Ca regulation
Levels who have high: Phosphate binders/regulating amount of Ca in diet
Low blood calcium client: premature infant who’s kidneys aren’t fully developed

15. Disorders of Fluid Balance
Alterations in volume
Hypovolemia
Hypervolemia
Alterations in osmolality
From electrolytes imbalances
Sodium imbalances
Hyponatremia
Hypernatremia
Potassium imbalances (looking at acid/base balance as well)
Hypokalemia (look at albumin levels first)
Concerns: bone abnormalities/blood clotting
Hyperkalemia (look at renal status)
For Na and K imbalances, look at the Composition of fluid/amount of Na or K in solution

16. Disorders of Fluid Balance
Calcium imbalance
Hypocalcemia
Hypercalcemia
Phosphorus imbalance (looking at a status of energy deficiency and acid/base balance)
Hypophosphatemia
Hyperphosphatemia
Magnesium imbalance (looking at kidneys regulating this and bone)
Hypomagnesemia (muscle weakness and tremors)
Hypermagnesemia (muscle weakness)

17. Disorders of Fluid Balance
What are the…
Causes ?
Kidney disfunction
Clinical manifestations ?
Edema/fluid overload
Pitting edema: hyponatremia (sodium levels)
Laboratory findings ?
Treatment ?
Identify underlying cause
Might need to change the administration of:
Na, K, Pro, Fluid

18. Rapid changes in weight
Pulse/cardiac changes
Osmolality
© 2007 Thomson - Wadsworth

20. Rehydration: normal fluid osmolality: 300 mOsm/L (anything below this would be dehydrated)

21. Fluid and Electrolyte Balance
Assess for factors that affect fluid and electrolyte balance:
Disease or injury: burn patients, individuals who have sores in mouth or brain injury making it so they don’t physically consume enough, DKA
Medication or treatment: medications (Lasics) that pull out Na or K
Fluid loss: gun shot wound
Nutrient restriction: cardiovascular disease, renal disease
Oral intake: inadequate amount
Intake vs. output: concern with geriatric population