Download Fluid and Electrolytes All Slides

Introduction to Fluids &
Electrolytes
Learning Objective
On completion of this chapter, the learner will be able to:
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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).
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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.
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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
Nursing Care is directed toward:
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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?
Fluid Compartments
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Intracellular (ICF)
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fluids contained within the cells
Extracellular (ECF)
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(2/3 of the fluid)
(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
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Important in burns, shock and cardiovascular
Movement of Body Fluids: Important
Concept
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Body fluids are not static. Fluids &
electrolytes shift from compartment to
compartment.
Emphasis is always on maintaining
homeostasis
FLUID MOVEMENT:
review & see Table 11-2, p.
145 (Iggy)
Diffusion
Osmosis
Filtration
Active Transport
Osmosis
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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
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Normal = 270 – 300 (or 275 – 295)
Osmolality = number of mill-osmoles in
kilogram of solution
Isotonic Fluids
example: normal saline 0.9% NaCl
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No net fluid (water)
shifts occur because
the fluids are EQUALLY
concentrated
Hypotonic Fluids
example: 0.45% NaCl
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When a LESS
concentrated fluid is
placed next to a MORE
concentrated solution,
water moves to MORE
concentrated solution
to equalize the
solutions
Hypertonic Fluids
example: 3% NaCl
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When a MORE
concentrated fluid is
placed next to a LESS
concentrated solution,
water moves to the
MORE concentrated
solution to equalize the
solutions
Body Fluids
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Sources of fluid intake
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ingested fluids/foods
water as byproduct of metabolism
Fluid Loss
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Urine
Respiration
Perspiration
Gastrointestinal tract
KIDNEY FUNCTIONS
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Regulate fluid volume and osmolality
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Regulate electrolyte levels
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by selectively retaining & excreting e-lytes
Regulate pH (acid/base balance)
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by selectively retaining & excreting fluids
by selectively retaining & excreting H+
Excrete metabolic wastes & toxic substances
THE NEPHRON
REGULATORY MECHANISMS
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THIRST
KIDNEYS
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Kidney Function
HORMONES
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Renin-Angiotensin-Aldosterone
Anti-Diuretic Hormone
Parathormone
Anti-Diuretic Hormone
(think beer)
Parathyroid Hormone
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Important for Calcium and Phosphorus
balance
Where are the parathyroid glands????
Dehydration
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Isotonic dehydration: water & electrolytes lost
in equal proportions
Hypertonic dehydration: water loss exceeds
electrolyte loss
Hypotonic dehydration: electrolyte loss
exceeds water loss
Dehydration Etiology
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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!)
DEHYDRATION: FLUID VOLUME
DEFICIT nsg dx
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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)
Dehydration
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History (risk factors)
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age (very young & very old)
check loss of body weight
history of fluid losses
Dehydration
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ASSESSMENT/MANIFESTATIONS
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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
Dehydration
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Lab Assessment
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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
Nursing Diagnosis: FLUID VOLUME
DEFICIT
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Diet therapy
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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
Dehydration: Pediatric Implications
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Assessment Manifestations
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FONTANELS (anterior & posterior)
Give isotonic fluids
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Tend to be subtle & happen quickly
You have a site to observe on an infant that no
longer exists on an adult - ??
Pedialyte (Gatorade)
Professional Responsibility
Community Based Care: Adults &
Children
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Health teaching
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Home care management
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Diet, drugs, & avoidance in the future
control environmental temperature & humidification
family offers fluids frequently (avoid large amounts plain
water in formula fed infant – see under hyponatremia)
Health care resources
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Home care visit
Overhydration (nsg dx fluid volume excess)
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PATHOPHYSIOLOGY
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Isotonic = hypervolemia
Hypotonic = excessive fluid (water intoxication)
Hypertonic = rare, excessive sodium intake
SUMMARY: TOO MUCH FLUID!
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Steroids, heart failure, cirrhosis of the liver, renal failure,
adrenal gland disorders, excessive intake IV fluids or Sodium
(foods, meds, IV solutions)
FLUID VOLUME EXCESS
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ASSESSMENT/MANIFESTATIONS
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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
OVERHYDRATION (FVE)
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Diagnostic Tests
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Electrolytes
Decreased hematocrit & BUN (Blood urea
nitrogen)
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Caused by more water, less solute = hemodilution
Increased central venous pressure
Drug therapy
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Diuretics
Sodium & Water Restriction
Overhydration Nursing Diagnoses
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Fluid Volume Excess
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as above & assess I&O, vital signs, edema
daily weights
education: sodium
Risk for Impaired Skin Integrity
Potential: Respiratory Insufficiency