1. FLUID, ELECTROLYTE, AND ACID-BASE BALANCE
NUR Chapter 14

2. Body fluids Extracellular fluids (ECF)
Interstitial fluid - fills the spaces between most cells of the body
Intravascular fluid - plasma (WBC, RBC and platelets in this fluid)
Interstitial fluid is 15% of body weight
Intravascular fluid is 5% of body weight

3. Body fluids Intracellular fluids (ICF) Liquids within cell membranes
40% of body weight
Intracellular – 40% of body weight

4. Components in body fluids
Electrolyte
an element that when dissolved can carry an electrical current
Cations - (+) ; Anions - (-)
neuromuscular function
acid-base balance
Cations – positively charged
Anions – negatively charged

5. Components of body fluids
Minerals
ingested compounds
serve as catalysts in nerve response, muscle contraction, and metabolism of nutrients in foods, regulate electrolyte balance

6. Movement of body fluids
Diffusion
Area of higher concentration to an area of lower concentration till even distribution
Osmosis
Movement of a pure solvent, e.g. water through a semipermeable membrane from a solution that has a lower solute concentration to one that has a higher solute concentration

7. Osmotic pressure
Drawing power of water (dependent on the number or molecules in solution)
Isotonic
Hypotonic
Hypertonic
Isotonic - Solution with same osmolality as blood plasma
Hypotonic - Lesser concentration than blood plasma
Hypertonic - Greater concentration than blood plasma

8. Movement of body fluids
Filtration
Water and diffusible substances move together in response to fluid pressure
Active transport
Requires energy
Able to move larger molecules and go from less to greater concentration

9. Fluid Intake Hypothalamus - thirst control center
Oral fluid intake requires an alert state
Osmoreceptors - monitor osmolality

10. Fluid Output Loss through the kidneys and GI tract Insensible Sensible
not perceived by the person
Sensible
perceived by the person
occurs through excessive perspiration

11. Cations Sodium (Na+) Most abundant in the extracellular fluid
Maintains water balance, transmits nerve impulses, contracts muscles
Values mEq/L
Found in processes meats, snacks, canned foods, and table salt

12. Cation Potassium (K+) Major intracellular cation
Regulates neuromuscular excitability, muscular contraction, and acid-base
Value mEq/L
Found in whole grains, fruits, and vegetables

13. Cation
Calcium (Ca2+)
Cardiac conduction, blood coagulation, bone growth and formation, & muscular relaxation
Value mEq/L
Found in dairy products

14. Cation Magnesium (Mg2+) Second most important of intracellular fluids
Enzyme activities, muscular excitability
Value mEq/L

15. Electrolyte Imbalances
Hyponatremia
GI losses, sweating, & diuretics
S/S: N/V/D, abd cramps, personality change
Hypernatremia
Ingestion of large amounts
S/S: Dry tongue and mucous membranes, restlessness, convulsions, thirst, dry skin

16. Electrolyte imbalances
Hypokalemia
Causes: K+ wasting diuretics
N/V/D
polyuria
S/S: weak, irregular pulse
hypotension
weakness

17. Electrolyte imbalances
Hyperkalemia
Causes: Renal failure
S/S: irregular slow pulse, weakness, irritability

18. Electrolyte Imbalances
Hypocalcemia
Causes: Vitamin D deficiency
S/S: Numb and tingling fingers and circumoral region, muscle cramps
Hypercalcemia
Causes: osteoporosis, prolonged immobilization
S/S: decreased muscle tone, weakness, lethargy, kidney stones

19. Electrolyte imbalances
Hypomagnesemia
Causes: malnutrition and alcoholism polyuria
S/S: muscular tremors, hyperactive deep tendon reflexes
Hypermagnesemia
Causes: Renal failure
S/S: hypoactive deep tendon reflexes, shallow and slow respirations

20. Acid - Base Balance Blood pH - 7.35 - 7.45 paCO2 - 35 - 45
Bicarbonate (HCO3) mEq/L

21. Respiratory Acidosis pH < 7.35 paCO2 > 45 mm Hg
Causes: Respiratory failure
Hypoventilation
Resp muscles paralysis
Airway obstruction

22. Respiratory Alkalosis
pH > 7.45
paCO2 < 35 mm Hg
Causes: excessive exhalation of CO2 (hyperventilation)

23. Metabolic Acidosis pH < 7.35 bicarbonate - < 22 mEq/L
Causes: Starvation, DKA, Diarrhea, drug use

24. Metabolic Alkalosis pH > 7.45 bicarbonate > 26 mEq/L
Causes: excessive vomiting, prolonged gastric suctioning

25. Fluid & Electrolyte Imbalances
Burns - body fluid loss
Renal D/O - abnormal retention of Na, Cl, K
GI Disturbances - Loss of fluid, potassium, and chloride
Exercise

26. S/S electrolyte imbalance
Head: irritability
Fontanels: depressed, bulging
Eyes: sunken periorbital edema
Mouth: mucous membranes
CV: neck veins, edema, blood pressure
Resp: Crackles

27. Imbalances GI: abdomen, V/D Renal: Oliguria or anuria (FVD, FE)
Diuresis (FVE)
Increased urine spec. gravity (FVD)
Skin (Temp)
increased - met acidosis, hypernatremia
decreased - FVD

28. Replacement of fluids and electrolytes
Types of IV fluids
Isotonic
Hypertonic
Hypotonic

29. IV complications Infiltration Phlebitis Fluid overload Bleeding
IVF enter SQ space
Phlebitis
vein inflammation
S/S: pain, redness, warmth
Fluid overload
Fluids given too rapidly
Bleeding

30. Discontinuing an IV
Stop infusion
Remove tape
1 - 2 minute pressure

31. Blood transfusions Large bore catheter (18 ga or larger)
Give with normal saline
Baseline vital signs
Double check with two RNs
Begin transfusion slowly
Observe closely for first 15 min

32. Transfusion Reactions
Caused by:
blood incompatibility
allergic sensitivity
S/S: fever, chills, rash, hypotension, shock
Treatment: stop transfusion, give NS, save tubing, prepare for emergency drugs