1. Introduction to Fluids & Electrolytes

2. Learning Objective
On completion of this chapter, the learner will be able to:
1. Differentiate between osmosis, diffusion, filtration, and active transport.
2. Describe the role of the kidneys, lungs, and endocrine glands in regulating the body’s fluid composition and volume.
3. Identify the effects of aging on fluid and electrolyte regulation.
4. Plan effective care of patients with the following imbalances: fluid volume deficit and fluid volume excess; sodium deficit (hyponatremia) and sodium excess (hypernatremia); potassium deficit (hypokalemia) and potassium excess (hyperkalemia). .

3. 5. Describe the etiology, clinical manifestations, management, and nursing interventions for the following imbalances: calcium deficit (hypocalcemia) and calcium excess (hypercalcemia); magnesium deficit (hypomagnesemia) and magnesium excess (hypermagnesemia); phosphorus deficit (hypophosphatemia) and phosphorus excess (hyperphosphatemia); chloride deficit (hypochloremia) and chloride excess (hyperchloremia).
6. Explain the role of the lungs, kidneys, and chemical buffers in maintaining acid–base balance.
7. Compare metabolic acidosis and alkalosis with regard to causes, clinical manifestations, diagnosis, and management.

4. 8. Compare respiratory acidosis and alkalosis with regard to causes,
clinical manifestations, diagnosis, and management.
9. Interpret arterial blood gas measurements.
10. Demonstrate a safe and effective procedure of venipuncture.
11. Describe measures used for preventing complications of intravenous therapy

5. Nursing Care is directed toward:
Assessing for clients at risk
Monitoring clients for EARLY manifestations
Implement collaborative and nursing interventions to prevent or correct imbalances
What segment of the life span is at highest risk of fluid imbalances?

6. Fluid Compartments Intracellular (ICF) (2/3 of the fluid)
fluids contained within the cells
Extracellular (ECF) (1/3 of the fluid)
(Remember blood tests measure extracellular fluid only – that’s why sodium is high and potassium is low!)
Interstitial (between the cells)
Intravascular (plasma)
arteries, veins, capillaries
Transcellular
misc: urine, digestive secretions, perspiration etc.
Theoretical Third Space: trapped ECF in actual or potential body space due to disease or injury
Important in burns, shock and cardiovascular

7. Movement of Body Fluids: Important Concept
Body fluids are not static. Fluids & electrolytes shift from compartment to compartment.
Emphasis is always on maintaining homeostasis

8. FLUID MOVEMENT: review & see Table 11-2, p. 145 (Iggy)
Diffusion
Osmosis
Filtration
Active Transport

9. Osmosis
Movement of water across a semi-permeable membrane from an area of low solute concentration (lots of water) to an area of high solute concentration (less water) until even distribution (homeostasis) is achieved
Osmolarity = number of milli-osmoles in liter of solution
Normal = 270 – 300 (or 275 – 295)
Osmolality = number of mill-osmoles in kilogram of solution

10. Isotonic Fluids example: normal saline 0.9% NaCl
No net fluid (water) shifts occur because the fluids are EQUALLY concentrated

11. Hypotonic Fluids example: 0.45% NaCl
When a LESS concentrated fluid is placed next to a MORE concentrated solution, water moves to MORE concentrated solution to equalize the solutions

12. Hypertonic Fluids example: 3% NaCl
When a MORE concentrated fluid is placed next to a LESS concentrated solution, water moves to the MORE concentrated solution to equalize the solutions

13. Body Fluids Sources of fluid intake Fluid Loss ingested fluids/foods
water as byproduct of metabolism
Fluid Loss
Urine
Respiration
Perspiration
Gastrointestinal tract

14. KIDNEY FUNCTIONS Regulate fluid volume and osmolality
by selectively retaining & excreting fluids
Regulate electrolyte levels
by selectively retaining & excreting e-lytes
Regulate pH (acid/base balance)
by selectively retaining & excreting H+
Excrete metabolic wastes & toxic substances

15. THE NEPHRON

16. REGULATORY MECHANISMS
THIRST
KIDNEYS
Kidney Function
HORMONES
Renin-Angiotensin-Aldosterone
Anti-Diuretic Hormone
Parathormone

18. Anti-Diuretic Hormone (think beer)

19. Parathyroid Hormone Important for Calcium and Phosphorus balance
Where are the parathyroid glands????

20. Dehydration
Isotonic dehydration: water & electrolytes lost in equal proportions
Hypertonic dehydration: water loss exceeds electrolyte loss
Hypotonic dehydration: electrolyte loss exceeds water loss

21. Dehydration Etiology
Isotonic: inadequate fluid intake, fluids shifts between compartments, excessive loss of body fluids
Hypertonic: excessive perspiration, hyperventilation, fever, diarrhea, ketoacidosis
Hypotonic: chronic illness such as renal failure, excessive ingestion hypotonic fluids (babies & water!)

22. DEHYDRATION: FLUID VOLUME DEFICIT nsg dx
PATHOPHYSIOLOGY
Loss of GI fluids (vomiting, diarrhea, NG suctioning, fistulas, intestinal drainage, chronic abuse of laxatives and/or enemas)
Renal loss from diuretics
Water loss from sweating or heat
Blood loss (hemorrhage)
Fluid lost to Third Space (burns, trauma)

23. Dehydration History (risk factors) age (very young & very old)
check loss of body weight
history of fluid losses

24. Dehydration ASSESSMENT/MANIFESTATIONS
Hypotension (decreased systolic, narrowed pulse pressure, postural hypotension)
Weak, rapid pulse with collapsed veins
Decreased skin turgor, dry membranes
Output > Intake (urine high specific gravity)
Weight loss (1000 ml = 1000gm or 1 kg (2.2 pounds) ** very important

25. Dehydration Lab Assessment Serum electrolytes abnormal
Urine specific gravity high (urine is concentrated)
Low central venous pressure
Elevated hematocrit and BUN (blood urea nitrogen)
Caused by more solute, less water = hemoconcentration

26. Nursing Diagnosis: FLUID VOLUME DEFICIT
Diet therapy
Oral fluid replacement
Oral rehydration therapy
Pediatric implications to follow on future slide
Drug therapy (varies with type of dehydration)
IV = isotonic (safest)
0.9% NaCl, Ringer’s Lactate
Meds to treat underlying problem

27. Dehydration: Pediatric Implications
Assessment Manifestations
Tend to be subtle & happen quickly
You have a site to observe on an infant that no longer exists on an adult - ??
FONTANELS (anterior & posterior)
Give isotonic fluids
Pedialyte (Gatorade)
Professional Responsibility

28. Community Based Care: Adults & Children
Health teaching
Diet, drugs, & avoidance in the future
Home care management
control environmental temperature & humidification
family offers fluids frequently (avoid large amounts plain water in formula fed infant – see under hyponatremia)
Health care resources
Home care visit

29. Overhydration (nsg dx fluid volume excess)
PATHOPHYSIOLOGY
Isotonic = hypervolemia
Hypotonic = excessive fluid (water intoxication)
Hypertonic = rare, excessive sodium intake
SUMMARY: TOO MUCH FLUID!
Steroids, heart failure, cirrhosis of the liver, renal failure, adrenal gland disorders, excessive intake IV fluids or Sodium (foods, meds, IV solutions)

30. FLUID VOLUME EXCESS ASSESSMENT/MANIFESTATIONS Increased blood pressure
Strong, bounding pulse with neck vein distention
Taut skin turgor, moist mucous membranes
Intake > Output (urine low specific gravity)
Weight gain
Crackles in lung sounds, orthopnea, irritating cough

31. OVERHYDRATION (FVE) Diagnostic Tests Drug therapy Electrolytes
Decreased hematocrit & BUN (Blood urea nitrogen)
Caused by more water, less solute = hemodilution
Increased central venous pressure
Drug therapy
Diuretics
Sodium & Water Restriction

32. Overhydration Nursing Diagnoses
Fluid Volume Excess
as above & assess I&O, vital signs, edema
daily weights
education: sodium
Risk for Impaired Skin Integrity
Potential: Respiratory Insufficiency