Fluid and Electrolyte including fluid volume disorders: dehydration, hypovolemia, hypervolemia, water intoxication

1. Fluid & electrolytes
Prepared by:
Maria Carmela L. Domocmat, RN, MSN

3. http://www.mayoclinic.com/images/image_popup/fn7_waterinbody.jpg

4. Did you know?
● The total amount of water in the body of an
average adult is 37 litres.
● Human brains are 75% water.
● Human bones are 25% water.
● Human blood is 83% water.

5. Factors affecting body fluids
• Age
• Gender
• Body fat

6. FACTORS AFFECTING BODY FLUIDS
1. AGE - Older adults have less water content
than younger adults because of muscle mass loss
and decreased ratio of lean body mass to total
body weight.
2. GENDER - Males have more water content
than females because of increased stature and
lean body mass. Females have more body fats.
3. BODY FAT - contain little water

8. Water, Electrolyte
• Of the 40 liters of
water in the body
of an average
adult male, about
two-thirds is
intracellular, and
one-third is
extracellular

9. Fluid Compartments

11. Composition of Body Fluids
• Water is the universal solvent
• Solutes are broadly classified into
▫ Electrolytes
 inorganic salts, all acids and bases, some proteins
▫ Nonelectrolytes
 glucose, lipids, creatinine, urea
• Electrolytes have greater osmotic power than
nonelectrolytes
• Water moves according to osmotic gradients

12. Fluid & Elec
Composition

13. Electrolyte Composition of Body Fluids

14. Continuous
Mixing of Body
Fluids

15. Water intake and output

17. Water Balance

18. Water Balance and ECF Osmolality
• To remain properly hydrated, water intake must
equal water output
• Water intake sources
▫ Ingested fluid (60%) and solid food (30%)
▫ Metabolic water or water of oxidation (10%)

19. intake output
• Oral fluids
• Solid foods
• Metabolism
• Others
▫ Parenteral fluids
▫ Enemas
▫ Irrigating fluids
• Urine
• Insensible fluid loss
▫ Perspiration
▫ Feces
▫ Vaporization from lungs
• Others
▫ Emesis
▫ Drainage from fistula

20. Water Balance
• urine
production is
most
important in
the
regulation of
water
balance

21. Water Intake and Output

22. • Water output
▫ Urine (60%) and feces (4%)
▫ Insensible losses (28%), sweat (8%)
• Increases in plasma osmolality trigger thirst and
release of antidiuretic hormone (ADH)

23. Regulation of Water Output
1. KIDNEY
• kidney excrete 1-2 L/day
• Obligatory urine output/day = 400-600mL
depending on fluid intake
• What if you have less than 400mL output
in 24hrs?
▫ effect: retention of waste products
▫ can lead to lethal electrolyte imbalances, acidosis
and toxic buildup of nitrogen.
.

24. 2. INSENSIBLE WATER LOSS
• Water loss from skin, lungs and stool is 15-20
mL/kg/day in healthy adult.
• Excessive insensible water loss result in more hypertonic
ECF with smaller volume
• If this loss is not balanced by intake, the hypertonic and
dehydration can lead to hypernatremia (elevated serum
level).
.

25. Regulation of Water Output
• Dehydration
• osmotic pressure increases in
extracellular fluids
• osmoreceptors in
hypothalamus stimulated
• hypothalamus signals
posterior pituitary to release
ADH
• urine output decreases
• Excess Water Intake
• osmotic pressure decreases
in extracellular fluids
• osmoreceptors stimulated in
hypothalamus
• hypothalamus signals
posterior pituitary to
decrease ADH output
• urine output increases

26. Regulation of Water Intake
• The hypothalamic thirst center is stimulated:
• (increase in osmotic pressure of extracellular fluid stimulates
osmoreceptors in thirst center)
▫ By a decline in plasma volume of 10%–15%
▫ By increases in plasma osmolality of 1–2%
▫ Via baroreceptor input, angiotensin II, and other
stimuli

27. Regulation of Water Intake
• Thirst is quenched as soon as we begin to drink
water
• water is absorbed
• osmotic pressure of extracellular fluid returns to
normal
• Feedback signals that stimulate nerve impulses that
inhibit thirst center include:
▫ Drinking - moistening of the mucosa of the mouth and
throat
▫ distension of the stomach by water (activation of
stomach and intestinal stretch receptors)

28. Regulation
of Water
Intake:
Thirst
Mechanism

29. REGULATORY PROCESSES OF FLUID
AND ELECTROLYTE BALANCE

30. 1. FILTRATION( SOLVENT FLOW)
• movement of water through
cells and blood vessels because
of hydrostatic pressure, that is
from greater amount of
pressure to membrane with
lesser pressure.

31. CLINICAL FUNCTION AND
SIGNIFICANCE
Blood pressure is a hydrostatic filtering force that
moves whole blood from the heart to tissue area
where exchange of water, nutrients and waste
products occur when blood arrives at the tissue
capillary.

32. CLINICAL FUNCTION AND
SIGNIFICANCE

33. 2. DIFFUSION (SOLUTE FLOW)
Solutes move or spread from areas of high
concentration to areas of low concentration until
the particles are evenly distributed throughout a
space.
If the membrane is impermeable to substance, it
is "helped" across by carrier proteins - the
process
called facilitated diffusion.

34. 2. DIFFUSION (SOLUTE FLOW)

35. CLINICAL SIGNIFICANCE
• Diffusion is important in control and transport of gases
and in the movement of most electrolytes, atoms, and
molecules through cell membrane.
• Unlike capillaries, cell membranes are selective.
• They permit some substances while inhibit movement of
other substances.
• Ex. Even though glucose is higher in ECF, it cannot pass
through the cell without the help of insulin.

36. 2. DIFFUSION (SOLUTE FLOW)

38. 3.OSMOSIS (WATER FLOW)
The movement of water across cell membrane in the
direction where there is a high concentration of solute but
lower concentration of water until both spaces contain
same proportion of solutes and solvent.
A simple rule to remember is: SALT SUCKS
Salt is a solute. When it is concentrated inside or outside the cell, it
will suck the water in its direction.

39. 3.OSMOSIS (WATER FLOW)

40. 2. Tonicity determines the direction of
water flow

42. CLINICAL SIGNIFICANCE AND
FUNCTION
• The thirst mechanism is how osmosis helps maintain balance.
• When a person loses body water through sweats and most solutes
remain in
• ECF volume decreases that lead to increase osmolarity(solute
concentration).

43. CLINICAL SIGNIFICANCE AND
FUNCTION
• The cells in the thirst center shrinks as water moves to the
hypertonic ECF(higher solute conc.) cells in the thirst center shrinks
as water moves to the hypertonic ECF(higher solute conc.).
• The shrinking of cells trigger a person to drink enough water to
restore amount of water lost thorough sweats and therefore restore
ECF normal fluid osmolarity(fluid volume.

44. CLINICAL SIGNIFICANCE AND
FUNCTION

45. Regulation
of Water
Intake:
Thirst
Mechanism

46. Movement of Fluids
Between Compartments
• Net movements
of fluids between
compartments
result from
differences in
hydrostatic and
osmotic
pressures

47. 4. ACTIVE TRANSPORT
movement of a solute across the cell
membrane with expenditure of energy
(ATP) from high to low concentration or low to
high concentration

48. 4. ACTIVE TRANSPORT

49. CLINICAL SIGNIFICANCE
Cells use active transport to
control cell volume.
All cells function best when their
internal environments are
maintained separately from
the changes occurring in the
ECF environment.

50. Hormonal regulation

51. FLUID AND ELECTROLYTE BALANCE
Hormones secreted by the adrenal cortex is either
stimulated by decreased level of Na+ in ECF or
increased Na+ level in urine.

52. Hormones
1. Aldosterone
2. Antidiuretic hormone (ADH) or vasopressin
3. Natriuretic peptides (NPs)

53. a. Aldosterone
• Protects Na+ balance by preventing Na+ loss.
• Because Na+ exerts osmotic (water pulling)
pressure, water attempts to follow Na+ in
proportionate amount. As a result this Na+ -
water relationship and aldosterone secretion
helps regulate water balance.

54. Aldosterone

55. b. Anti-diuretic hormone
• vasopressin
• In an increased blood Na+ level( increased
osmolarity) result in shrinkage of cell and
triggers ADH release from posterior pituitary
gland. ADH acts on kidney tubules and
collecting ducts making them more permeable to
water. As a result more water is reabsorbed and
returned to the blood making it more dilute.

56. Influence and Regulation of ADH
• Water reabsorption in collecting ducts is
proportional to ADH release
• Low ADH levels produce dilute urine and reduced
volume of body fluids
• High ADH levels produce concentrated urine
• Hypothalamic osmoreceptors trigger or inhibit ADH
release
• Factors that specifically trigger ADH release include
prolonged fever; excessive sweating, vomiting, or
diarrhea; severe blood loss; and traumatic burns

57. Mechanisms
and
Consequences
of ADH
Release

58. c. Lymph
• extra fluid that leaks from the capillaries.
• It is returned from the systemic circulation by
lymph vessels to prevent blood volume deficits
and edema in the interstitial spaces

59. d. Natriuretic peptides
• hormones secreted by special cells that line the
heart's atria and ventricles in response to increased
blood volume and pressure, which stretch the heart
tissue.
• NP binds to the receptor sites in the nephrons,
creating effects that oppose renin-angiotensin
system.
• When either ANP or BNP is secreted, kidney
reabsorption of Na+ is inhibited.
• The outcome is increased urine output with high
Na+ content which result in decreased circulating
volume and decreased blood osmolarity

60. Figure 26.10
Mechanisms
and
Consequences
of ANP Release

63. Pathway of RAAS

64. Disorders of Water Balance

65. Fluid Imbalances
Dehydration
Hypovolemia
Hypervolemia
Water intoxication

67. Disorders of Water Balance:
Dehydration
• Water loss exceeds water intake and the body is
in negative fluid balance
• Causes include:
▫ hemorrhage, severe burns, prolonged vomiting or
diarrhea, profuse sweating, water deprivation, and
diuretic abuse

68. Disorders of Water Balance:
Dehydration
• Signs and symptoms:
▫ cottonmouth, thirst, dry flushed skin, and oliguria
• Prolonged dehydration may lead to weight loss,
fever, and mental confusion
• Other consequences include hypovolemic shock
and loss of electrolytes

69. Disorders of Water Balance:
Dehydration
Excessive loss of H2O from
ECF
1 2 3ECF osmotic
pressure rises
Cells lose H2O
to ECF by
osmosis; cells
shrink
(a) Mechanism of dehydration

70. • Renal insufficiency or an extraordinary amount
of water ingested quickly can lead to cellular
overhydration, or water intoxication
• ECF is diluted – sodium content is normal but
excess water is present
• The resulting hyponatremia promotes net
osmosis into tissue cells, causing swelling
• These events must be quickly reversed to
prevent severe metabolic disturbances,
particularly in neurons
Disorders of Water Balance:
Hypotonic Hydration

71. Figure 26.7b
Disorders of Water Balance:
Hypotonic Hydration
Excessive H2O enters
the ECF
1 2 ECF osmotic
pressure falls
3 H2O moves into
cells by osmosis;
cells swell
(b) Mechanism of hypotonic hydration

72. http://www.fashion-writings.com/img/tu/hypertonic-hypotonic-or-isotonic-solution/553px-
Osmotic_pressure_on_blood_cells_diagram_svg.png

75. Clinical Correlates of Dehydration
Severity Fluid Deficit in mL/kg
(percent body wt)*
Signs
Infants Adolescents
Mild 50 (5%) 30 (3%) Slightly dry buccal mucous
membranes, increased thirst, slightly
decreased urine output
Moderate 100 (10%) 50–60 (5–6%) Dry buccal mucous membranes,
tachycardia, little or no urine output,
lethargy, sunken eyes and fontanelles,
loss of skin turgor
Severe 150 (15%) 70–90 (7–9%) Same as moderate plus a rapid, thready
pulse; no tears; cyanosis; rapid
breathing; delayed capillary refill;
hypotension; mottled skin; coma
*Standard estimates for children between infancy and adolescence have not been established. For children between these age
ranges, clinicians must estimate values between those for infants and those for adolescents based on clinical judgment.

76. http://www.willisms.com/archives/dehydration.gif

77. Dehydration
• Loss of body fluids  increased
concentration of solutes in the blood and a
rise in serum Na+ levels
• Fluid shifts out of cells into the blood to
restore balance
• Cells shrink from fluid loss and can no longer
function properly

78. Clients at Risk
•Confused
•Comatose
•Bedridden
•Infants
•Elderly
•Enterally fed

79. What Do You See?
• Irritability
• Confusion
• Dizziness
• Weakness
• Extreme thirst
•  urine output
• Fever
• Dry
skin/mucous
membranes
• Sunken eyes
• Poor skin turgor
• Tachycardia

81. Management
• Fluid restoration
▫ Oral rehydration
▫ IV rehydration
• Correction of underlying
problem
▫ Antiemetic
▫ Antidiarrheal
▫ Antibiotics
▫ Antipyretics
• Fluid Replacement - oral or IV
over 48 hrs.
• Monitor symptoms and vital
signs
• Maintain I&O
• Maintain IV access
• Daily weights
• Skin and mouth care

82. Composition of Appropriate Oral
Rehydration Solutions
Solution
Carbo-
hydrate
(g/dL)
Sodium
(mEq/L)
Potassium
(mEq/L)
Base
(mEq/L)
Osmo-
lality
Pedialyte 2.5 45 20 30 250
Infalyte 3 50 25 30 200
Rehydralyte 2.5 75 20 30 310
WHO/UNICEF* 2 90 20 30 310
* World Health Organization/United Nations Children's Fund

83. Composition of Inappropriate Oral
Rehydration Solutions
Solution
Carbohydr
ate (g/dL)
Sodium
(mEq/L)
Potassium
(mEq/L)
Base
(mEq/L)
Osmolality
Apple juice 12 0.4 26 0 700
Ginger ale 9 3.5 0.1 3.6 565
Milk 4.9 22 36 30 260
Chicken
broth
0 2 3 3 330

85. Hypovolemia
• Isotonic fluid loss
from the
extracellular
space
• Can progress to
hypovolemic
shock
• Caused by:
▫ Excessive fluid
loss
(hemorrhage)
▫ Decreased fluid
intake
▫ Third space
fluid shifting

86. What Do You See?
• Mental status
deterioration
• Thirst
• Tachycardia
• Delayed capillary
refill
• Orthostatic
hypotension
• Urine output < 30
ml/hr
• Cool, pale
extremities
• Weight loss

87. What Do We Do?
• Fluid replacement
• Albumin
replacement
• Blood transfusions
for hemorrhage
• Dopamine to
maintain BP
• MAST trousers
for severe shock
• Assess for fluid
overload with
treatment

89. Hypervolemia
• Excess fluid in the extracellular compartment
as a result of fluid or sodium retention,
excessive intake, or renal failure
• Occurs when compensatory mechanisms fail
to restore fluid balance
• Leads to CHF and pulmonary edema

90. What Do You See?
• Tachypnea
• Dyspnea
• Crackles
• Rapid, bounding pulse
• Hypertension
• S3 gallop
• Increased CVP,
pulmonary artery
pressure and pulmonary
artery wedge pressure
(Swan-Ganz)
• JVD
• Acute weight gain
• Edema

91. Edema
• Fluid is forced into tissues by the hydrostatic
pressure
• First seen in dependent areas
• Anasarca - severe generalized edema
• Pitting edema
• Pulmonary edema

92. Disorders of Water Balance: Edema
• Atypical accumulation of fluid in the interstitial
space, leading to tissue swelling
• Caused by anything that increases flow of fluids
out of the bloodstream or hinders their return
• Factors that accelerate fluid loss include:
▫ Increased blood pressure, capillary permeability
▫ Incompetent venous valves, localized blood vessel
blockage
▫ Congestive heart failure, hypertension, high blood
volume

93. Edema
• Hindered fluid return usually reflects an
imbalance in colloid osmotic pressures
• Hypoproteinemia – low levels of plasma
proteins
▫ Forces fluids out of capillary beds at the arterial
ends
▫ Fluids fail to return at the venous ends
▫ Results from protein malnutrition, liver disease,
or glomerulonephritis

94. Edema
• Blocked (or surgically removed) lymph vessels:
▫ Cause leaked proteins to accumulate in interstitial
fluid
▫ Exert increasing colloid osmotic pressure, which
draws fluid from the blood
• Interstitial fluid accumulation results in low
blood pressure and severely impaired circulation

99. Management
• Restriction of Sodium and
fluids
• Monitor vital signs
• Hourly I&O
• Breath sounds
• Monitor ABGs and labs
• Elevate HOB and give O2 as
ordered
• Maintain IV access
• Skin & mouth care
• Daily weights
• Promote urine output
▫ Diuretics
▫ ACE inhibitors, ARBs
(angiotensin II receptor
blockers), low-dose beta-
blockers, aldactone
antagonists

101. Water Intoxication
• Hypotonic
extracellular fluid
shifts into cells to
attempt to restore
balance
• Cells swell

102. Water Intoxication
• Causes:
▫ SIADH
▫ Rapid infusion of hypotonic solution
▫ Excessive tap water NG irrigation or enemas
▫ Psychogenic polydipsia

103. What Do You See?
• Signs and symptoms of increased intracranial
pressure
▫ Early: change in LOC, N/V, muscle weakness,
twitching, cramping
▫ Late: bradycardia, widened pulse pressure,
seizures, coma

104. What Do We Do?
• Prevention is the best
treatment
• Assess neuro status
• Monitor I&O and vital signs
• Fluid restrictions
• IV access
• Daily weights
• Monitor serum Na+
• Seizure precautions

105. Volume depletion
• Postural hypotension
• Tachycardia
• Absence of JVP @ 45o
• Decreased skin turgor
• Dry mucosae
• Supine hypotension
• Ascites
• Organ failure
Volume overload
• Hypertension
• Tachycardia
• Raised JVP / gallop rhythm
• Edema
• Pleural effusions
• Pulmonary edema
• Oliguria
• Organ failure

106. ASSESSMENT OF FLUID AND
ELECTROLYTE BALANCE

107. 1. History data – Gordon’s Functional Health
Pattern
a. INTAKE AND OUTPUT
exact intake and output volume.
amount of fluids and foods ingested
to determine amount of osmolarity.
b. MEDICATIONS
check laxatives, diuretics with dosage and the length of
time taken and adherence with drug regimen. Misuse
and over use of these
drugs can lead to serious imbalance.

108. c. WEIGHT
daily weight measurement and body weight changes,
thirst or excessive drinking, exposure to hot
environments, and presence of disorders such as kidney
and endocrine diseases.(DM, Addison's disease,
Cushing's and diabetic insipidus).
d. Level of consciousness
awareness of time, place and person. confusion
associated with electrolyte imbalance.

109. PHYSICAL ASSESSMENT
a. Hydration
alert, moist eyes and mucous membranes.
b. Urine output nearly the same with amount
ingested with urine specific gravity of 1.015.

110. c. Good skin turgor
Pinch a fold of skin in areas that have little fat
tissue such as over the sternum, forehead or
back of hand. Folded skin should return
immediately to its original shape. Decreased
turgor is a sign of dehydration when the fold
slowly rebounds. (tenting) Older person is hard
to assess because of loss of skin elasticity related
to aging.
• Check for dryness of skin including nose, eyes,
conjunctiva and mucous membranes. A dry,
sticky, cottony mouth, the absence of tears,
weight loss and decreased urine output all
indicate decreased fluid volume.

111. d. NEUROLOGIC AND BEHAVIORAL
ASSESSMENT
In hypertonic states, neuron shrinkage may
induce nervous excitability, hyperactivity and
convulsions, coma and death.
Muscle tone and strength, movement,
coordination and tremors
e. CARDIAC SYSTEM
Heart rate, strength of contractions and presence of
dysrhythmias

112. f. GASTROINTESTINAL SYSTEM
Peristalsis may indicate changes of excitable membrane
function. Decreased or increased motility
g. INSENSIBLE WATER LOSS
Fluid loss from wounds, gastric or intestinal drainage,
hemorrhage and other body secretions.

113. h. Previous Findings
Mental status, physical exam, and laboratory
data. Fluid and electrolyte imbalance can occur
quickly, be familiar with the patient's baseline
assessment data to detect changes.

114. 3. PSYCHOSOCIAL ASSESSMENT
Depressed clients may refuse fluids.
Clients with bulimia or anorexia nervosa may
abuse laxatives or may induce vomiting.
Alcohol or drug abuse