NURS 140 Fluid and electrolyles EXAM STUDY
GUIDE 2023 A+ PASS ASSUARED
Diffusion is the movement of molecules from an area of higher concentration
to an area of lower concentration.
Osmotic factors include
• colloid osmotic pressure which is caused by proteins and
• osmotic pressure which is created primarily by sodium
Capillary fluid flow is directly related to the difference of pressure between
the arterial and venous ends of capillaries.
Arterial hydrostatic pressure (caused by the pumping action of the heart)
pushes water, electrolytes, and nutrients through the capillary walls.
Venous colloid osmotic pressure (created by plasma proteins) pulls water,
electrolytes, and cell waste products into the capillary through the capillary
walls.
Volume imbalances involve sodium (Na+) and water (H2O) increasing or
decreasing together. Examples of ways this happens include:
• Changes in interstitial fluid volume
• Changes in intravascular volume
• Third space fluid shifts (ascites, pleural or pericardial effusions)
Fluid shifts can occur in several ways:decreased vascular colloid osmotic
pressure (pressure created by Plasma proteins. Pulls fluid back into blood vessels at venous end of
the capillary bed. Also called oncotic pressure)increased capillary hydrostatic pressure (a
pushing pressure
at the arterial end of the capillary bed. Forces H2O, oxygen, and nutrients through capillary walls
into interstitial spaces.)
• increased capillary permeability
• lymph obstruction
Decreased colloid osmotic (oncotic) pressure - A decrease in serum protein (as
in malnutrition, burns, nephrosis, or liver disease) results in low colloid
osmotic pressure.
What would be the result of low colloid osmotic (oncotic) pressure?
A.
Less water pulled into the blood vessel from the interstitial spaces.
B.
More water pulled into blood vessels from interstitial spaces.
,NURS 140 Fluid and electrolyles EXAM STUDY
GUIDE 2023 A+ PASS ASSUARED
Increased capillary hydrostatic pressure
Increased venous hydrostatic pressure, as in heart failure or cirrhosis,
prevents water from moving from the interstitial space into the vascular
space. The hydrostatic pressure is higher at the venous end of the capillary
than the colloid oncotic pressure, so water is not pulled back into the
vascular bed. What would be the likely result?
A.
circulatory overload
B.
tissue edema
An increase in capillary hydrostatic pressure can also cause more fluid and
solutes to be forced out of the blood vessel at the arterial end of the
capillary bed, or
prevent colloid osmotic pressure from pulling water in at the venous end.
This increases the amount of fluid in the interstitial space.
Increased capillary permeability
When there is damage to blood vessels as in trauma or burns, proteins leak
into
the interstitial space. The osmotic pull (gradient) that would ordinarily pull
water back into the blood vessel is reduced. As a result, fluid is pulled from
the intravascular area into the interstitial space, or third space areas such as
the abdominal cavity.
The result is tissue edema, since the protein in the interstitial space attracted
water.
Vasodilation
Inflammation, burns, or allergic reaction cause vasodilation and increased
capillary permeability, causing both water and solutes to move out into the
tissues creating tissue edema.
Lymph Obstruction
When lymph nodes are removed, or in cancer metastasis, fluid and protein
are retained in interstitial spaces. The increase in interstitial protein reduces
the osmotic gradient and causes water to be held in the interstitial space.
Obstruction to lymph capillaries creates external pressure which forces the
lymph fluid out into the interstitial space, causing edema.
Sodium and water excess (Hypervolemia) - abnormal increase in blood
volume. This can occur when there is increased sodium (Na+) intake, heart
failure, or aldosteronism. Heart failure causes reduced renal blood flow
and retention of sodium and water. Edema and increased vascular volume
results.
Reduced renal function is a factor due to inability of the kidney to eliminate
,NURS 140 Fluid and electrolyles EXAM STUDY
GUIDE 2023 A+ PASS ASSUARED
water.
, NURS 140 Fluid and electrolyles EXAM STUDY
GUIDE 2023 A+ PASS ASSUARED
Hypervolemia involves retention of both water and electrolytes (especially sodium). There is
usually an increase in the serum sodium which causes water retention.
Hypervolemia may also occur when the serum sodium level decreases due to water retention or
the effects of ADH ((antidiuretic hormone) a hormone secreted by the posterior lobe of the
pituitary gland that conserves water).
Causes of fluid volume excess include:
• congestive heart failure
• renal failure
• cirrhosis of the liver
• Cushing's syndrome
• Excessive use of corticosteroid drugs
• Excessive use of salt (sodium chloride)
• Excessive amounts of sodium-containing IV fluids
Hypervolemia may be manifested by:
• weight gain, increased abdominal girth
• peripheral edema
• distended neck and peripheral veins
• bounding, full pulse
• polyuria
• pulmonary edema, moist rales
• ascites, pleural effusion
• elevated central venous pressure (CVP)
• serum sodium may be normal or decreased
• hematocrit may be decreased
• low BUN(blood urea nitrogen) –blood, an end -product of protein metabolism
and nitrogen
Management of fluid volume excess includes:
• treat the problem, if possible
• limit fluid intake, using clinical situation as guide
• diuretics to promote fluid and sodium loss
• restrict sodium intake to reduce thirst
On average, we have 40 liters (40,000 ml) of fluid which make up 60% of body weight. Of
the 40 liters, 25 (25,000 ml) are intracellular fluids about 40%. Extracellular
fluids account for the remaining 15 liters (15,000 ml). Of that, about 10
liters (10,000 ml)
is interstitial fluid. And the 15 liters of extracellular fluids make up roughly
20% of body weight.
The intracellular fluids (ICF) make up the largest portion,
approximately 40%. The extracellular fluids (ECF), which include
interstitial fluids (ISF)
and intravascular fluids (plasma), make up roughly 20% of body weight.
GUIDE 2023 A+ PASS ASSUARED
Diffusion is the movement of molecules from an area of higher concentration
to an area of lower concentration.
Osmotic factors include
• colloid osmotic pressure which is caused by proteins and
• osmotic pressure which is created primarily by sodium
Capillary fluid flow is directly related to the difference of pressure between
the arterial and venous ends of capillaries.
Arterial hydrostatic pressure (caused by the pumping action of the heart)
pushes water, electrolytes, and nutrients through the capillary walls.
Venous colloid osmotic pressure (created by plasma proteins) pulls water,
electrolytes, and cell waste products into the capillary through the capillary
walls.
Volume imbalances involve sodium (Na+) and water (H2O) increasing or
decreasing together. Examples of ways this happens include:
• Changes in interstitial fluid volume
• Changes in intravascular volume
• Third space fluid shifts (ascites, pleural or pericardial effusions)
Fluid shifts can occur in several ways:decreased vascular colloid osmotic
pressure (pressure created by Plasma proteins. Pulls fluid back into blood vessels at venous end of
the capillary bed. Also called oncotic pressure)increased capillary hydrostatic pressure (a
pushing pressure
at the arterial end of the capillary bed. Forces H2O, oxygen, and nutrients through capillary walls
into interstitial spaces.)
• increased capillary permeability
• lymph obstruction
Decreased colloid osmotic (oncotic) pressure - A decrease in serum protein (as
in malnutrition, burns, nephrosis, or liver disease) results in low colloid
osmotic pressure.
What would be the result of low colloid osmotic (oncotic) pressure?
A.
Less water pulled into the blood vessel from the interstitial spaces.
B.
More water pulled into blood vessels from interstitial spaces.
,NURS 140 Fluid and electrolyles EXAM STUDY
GUIDE 2023 A+ PASS ASSUARED
Increased capillary hydrostatic pressure
Increased venous hydrostatic pressure, as in heart failure or cirrhosis,
prevents water from moving from the interstitial space into the vascular
space. The hydrostatic pressure is higher at the venous end of the capillary
than the colloid oncotic pressure, so water is not pulled back into the
vascular bed. What would be the likely result?
A.
circulatory overload
B.
tissue edema
An increase in capillary hydrostatic pressure can also cause more fluid and
solutes to be forced out of the blood vessel at the arterial end of the
capillary bed, or
prevent colloid osmotic pressure from pulling water in at the venous end.
This increases the amount of fluid in the interstitial space.
Increased capillary permeability
When there is damage to blood vessels as in trauma or burns, proteins leak
into
the interstitial space. The osmotic pull (gradient) that would ordinarily pull
water back into the blood vessel is reduced. As a result, fluid is pulled from
the intravascular area into the interstitial space, or third space areas such as
the abdominal cavity.
The result is tissue edema, since the protein in the interstitial space attracted
water.
Vasodilation
Inflammation, burns, or allergic reaction cause vasodilation and increased
capillary permeability, causing both water and solutes to move out into the
tissues creating tissue edema.
Lymph Obstruction
When lymph nodes are removed, or in cancer metastasis, fluid and protein
are retained in interstitial spaces. The increase in interstitial protein reduces
the osmotic gradient and causes water to be held in the interstitial space.
Obstruction to lymph capillaries creates external pressure which forces the
lymph fluid out into the interstitial space, causing edema.
Sodium and water excess (Hypervolemia) - abnormal increase in blood
volume. This can occur when there is increased sodium (Na+) intake, heart
failure, or aldosteronism. Heart failure causes reduced renal blood flow
and retention of sodium and water. Edema and increased vascular volume
results.
Reduced renal function is a factor due to inability of the kidney to eliminate
,NURS 140 Fluid and electrolyles EXAM STUDY
GUIDE 2023 A+ PASS ASSUARED
water.
, NURS 140 Fluid and electrolyles EXAM STUDY
GUIDE 2023 A+ PASS ASSUARED
Hypervolemia involves retention of both water and electrolytes (especially sodium). There is
usually an increase in the serum sodium which causes water retention.
Hypervolemia may also occur when the serum sodium level decreases due to water retention or
the effects of ADH ((antidiuretic hormone) a hormone secreted by the posterior lobe of the
pituitary gland that conserves water).
Causes of fluid volume excess include:
• congestive heart failure
• renal failure
• cirrhosis of the liver
• Cushing's syndrome
• Excessive use of corticosteroid drugs
• Excessive use of salt (sodium chloride)
• Excessive amounts of sodium-containing IV fluids
Hypervolemia may be manifested by:
• weight gain, increased abdominal girth
• peripheral edema
• distended neck and peripheral veins
• bounding, full pulse
• polyuria
• pulmonary edema, moist rales
• ascites, pleural effusion
• elevated central venous pressure (CVP)
• serum sodium may be normal or decreased
• hematocrit may be decreased
• low BUN(blood urea nitrogen) –blood, an end -product of protein metabolism
and nitrogen
Management of fluid volume excess includes:
• treat the problem, if possible
• limit fluid intake, using clinical situation as guide
• diuretics to promote fluid and sodium loss
• restrict sodium intake to reduce thirst
On average, we have 40 liters (40,000 ml) of fluid which make up 60% of body weight. Of
the 40 liters, 25 (25,000 ml) are intracellular fluids about 40%. Extracellular
fluids account for the remaining 15 liters (15,000 ml). Of that, about 10
liters (10,000 ml)
is interstitial fluid. And the 15 liters of extracellular fluids make up roughly
20% of body weight.
The intracellular fluids (ICF) make up the largest portion,
approximately 40%. The extracellular fluids (ECF), which include
interstitial fluids (ISF)
and intravascular fluids (plasma), make up roughly 20% of body weight.
