Electrolytes and Fluid Flashcards
Fluid Balance at the Capillary Level relies on a balance between what two forces?
(pushing force of) hydrostatic pressure and (pulling force of) oncotic pressure
At the arterial end of the capillary, is hydrostatic pressure is higher or lower the oncotic pressure?
Higher
At the arterial end of the capillary, hydrostatic pressure is higher than oncotic pressure in the capillary, so fluid moves and is pushed IN or OUT?
Out (into the interstitial space)
Current research shows interstitial hydrostatic pressure has a small negative or positive value?
small negative value
Current research shows that interstitial hydrostatic pressure has a small negative value and contributes slightly to the movement of fluid from the ____________ to the __________
capillary and tissue
At the venous end of the capillary, much of the fluid has moved to the interstitial space, leaving what behind?
solutes (in particular, the plasma proteins)
At the venous end of the capillary, this creates a higher or lower capillary osmotic pressure?
Higher
At the venous end of the capillary, much of the fluid has moved to the interstitial space, leaving the solutes (in particular, the plasma proteins) behind
This creates higher capillary osmotic pressure which effectively does what to the fluid?
pulls fluid from the interstitial space back into the vessel
At the venous end of the capillary, much of the fluid has moved to the interstitial space, leaving the solutes (in particular, the plasma proteins) behind
This creates higher capillary osmotic pressure which effectively pulls fluid from the _______________ __________ back into the _______
Some particles (such as glucose and electrolytes) move from the vessel into the interstitial space and creates interstitial colloidal osmotic pressure, pulling a small amount of fluid into the interstitial space
interstitial space and vessel
At the venous end of the capillary, much of the fluid has moved to the interstitial space, leaving the solutes (in particular, the plasma proteins) behind
This creates higher capillary osmotic pressure which effectively pulls fluid from the interstitial space back into the vessel
Some particles (such as _________ and ____________) move from the vessel into the interstitial space and creates interstitial colloidal osmotic pressure, pulling a small amount of fluid into the interstitial space
glucose and electrolytes
Excess interstitial fluid is taken up by what?
the lymphatics (and returned to the central circulation)
To review, fluid balance is determined by the push and pull of fluids across what type of membrane?
Semi-permeable capillary membrane
Normal movements of fluids depends on the integrity of the capillary membrane.
True or False?
True
Increased capillary hydrostatic pressure can cause what to occur?
high amounts of fluid to leave the capillary
If hydrostatic pressure continues to be high at the ends of the capillary, net movement will be IN or OUT of the capillary?
Out (of the capillary)
Increased capillary hydrostatic pressure can result from what two reasons?
Hypertension and from an increase in fluid volume (for example in the case of sodium and water retention)
Hydrostatic pressure also increases if there is any back-up of blood flow.
- For example, a DVT might obstruct venous blood flow, resulting in a higher than normal pressure at the venous end of the capillary.
True or False?
True
A lack of sufficient capillary oncotic pressure could occur. What does oncotic pressure do, push or pull the fluid? At which end of the capillary?
Pull the fluid (back into the intravascular space) and at the venous end
What is the most prevalent colloid (or solid) in the plasma?
albumin
Any clinical situation that results in decreased albumin, can result in a decrease of what type of pressure?
capillary oncotic pressure
What are 4 common medical diagnoses associated with low albumin?
burns, liver disease, malnutrition, and excessive wound drainage
Increased interstitial colloidal osmotic pressure could occur. In this case, what could escape into the interstitial fluids? What do they take with them and where is it held?
solutes (particles) and they will take fluid with them and hold that fluid in the interstitial space
Recall that the capillary should only allow _________ solutes to escape.
some
Capillary permeability increases in response to what of the inflammatory process (leaky capillaries)?
chemical mediators
An increase in tissue hydrostatic pressure could occur. The can happen when what is obstructed?
lymphatics (fluid is not removed)
What can occur if there is an increase in tissue hydrostatic pressure, the lymphatics are obstructed for some reason and do not remove excess fluid.
Lymphedema
The fourth mechanism that results in fluid imbalance is an increase in tissue hydrostatic pressure.
This can happen when the lymphatics are obstructed for some reason and do not remove excess fluid.
They are also complicated by increased tissue oncotic pressure which continues to pull fluid from the vessel.
True or False?
True
An increase in tissue hydrostatic pressure could occur.
Lymphatic obstruction can occur in what two instances?
liver disease or from physical obstruction from surgery
What can represent an increase in fluid in the interstitial space?
Edema
When there is an increased capillary hydrostatic pressure, it causes what?
fluid to move into the tissue (eventually edema)
What does a decrease in plasma proteins result in?
The lack of “pull” factors means that fluid remains in the interstitial space instead of moving back to the vessel.
decreased capillary oncotic pressure (this is edema)
Leaky capillaries or increased capillary permeability results in the loss of what to the interstitial space?
This movement is accompanied by fluid and the solutes keep the fluid in the interstitial space.
intravascular proteins and other solids (this is edema)
Lymphatic obstruction results in decreased absorption of what?
interstitial fluid (therefore is edema)
What is it known as when fluid shifts into the transcellular space and cannot be pushed or pulled out of that space OR if there is an obstruction to lymphatic flow and fluid becomes trapped?
(The transcellular compartment is a small subdivision of the extracellular fluid compartment)
third spacing
What are some examples of transcellular space?
joint spaces, the pericardial and pleural cavities, the peritoneum and ocular fluid
Normally, fluid moves in and out of transcellular spaces using the same mechanisms as usual.
True or False?
True
As with edema (fluid trapped in the interstitial space), the fluid is not readily available for exchange with ECF and therefore is referred to as what?
non-functional
In the brain, edema is associated with what two things?
infectors or trauma (both initiate an inflammatory response)
Although the skull is an enclosed space with little room for extra fluid, cerebral edema is not very life threatening.
True or False?
False
Because the skull is an enclosed space with little room for extra fluid, cerebral edema is life threatening
What are these signs of:
headaches, altered level of consciousness or coma, abnormal pupil size or reflexive response, changes in patterns of respiration, and changes in muscle tone and abnormal posturing
Intracranial Pressure (ICP)
Swelling of airway constitutes what?
an acute, life-threatening condition
Swelling of airway constitutes an acute, life-threatening condition
It is frequently due to an inflammatory response to what two things?
allergens or microorganisms
What may result in difficulty swallowing, anxiety, stridor, possible airway obstructions, and asphyxia?
Airway swelling
When fluid is forced out of the capillaries at the level of the lungs and accumulates around the alveoli, the result is a decrease in what two things?
a decrease in gas exchange and a decrease in the ability of the lungs to inflate
What type of edema may occur with the presentation of these symptoms:
anxiety, restlessness, diminished breath sounds, and/or crackles
lung edema
What type of edema may occur with the presentation of these symptoms:
anxiety, restlessness, diminished breath sounds, and/or crackles
lung edema
What is the term for fluid that collects in the peritoneal cavity? Is this an example of third spacing?
ascites and yes
With abdomen edema, this accumulation of fluid could be due to increased intravascular hydrostatic pressure that results when which vein is affected?
the portal vein (by liver cirrhosis)
With abdomen edema, a significant inflammatory response to something like an abdominal girth and a protruding umbilicus.
True or False?
True
With abdomen edema, the client may complain of abdominal discomfort and if the accumulation of fluid is considerable, shortness of breath when the expansion of the diaphragm is impeded by fluid.
True or False?
True
With intestinal edema, clients may experience a third space loss of fluid inside where?
the lumen and wall of the intestine, if obstructed
What are the two reasons why peripheral edema may occur?
obstruction of venous blood flow (which increases capillary hydrostatic pressure) and due to obstruction in lymphatic drainage
Where does peripheral edema predominately occur in ambulatory patients?
lower extremities
Where does peripheral edema predominately occur in bedridden patients?
sacral area
Peripheral Edema can occur:
Predominantly in the lower extremities in ambulatory patients
Also occurs in the sacral area in bedridden patients;
In both cases, this is referred to as what?
“dependent” edema
Edema that is related to salt retention is usually called what?
(When a finger is pressed into the edematous area, the fluid in the soft tissue shifts and when the finger is removed, a “pit” is evident)
“pitting” edema
What type of edema is only apparent after significant amounts of fluid have collected?
Overt edema
Health care team (doctors, nurses, etc.) need to determine the mechanisms underlying a client’s edema, then treat/correct accordingly to correct or control what?
the cause
Treatment may be simple or complex for edema, depending on the situation?
True or False?
True
If edema is related to malnutrition and the lack of albumin, an obvious solution would be to ensure the client consumes what?
adequate amounts of protein
If the mechanism responsible for edema is a lack of albumin intravascularly, but the problem is that a massive inflammatory response has created capillary permeability so protein is leaking from the vessels.
The treatment of this problem would be more complex.
In this case, the client would require transfusions of albumin or other colloid solutions to increase the capillary oncotic pressure, but unless the problem of increased capillary permeability is resolved, albumin will continue to move to the interstitial space and will take fluid with it, increasing the edema
True or False?
True
The body’s fluid-conserving mechanisms can further complicate the problem of edema
What body part will conserve water and sodium, effectively increasing the capillary hydrostatic pressure and increasing the edema?
the kidneys
When there increased ECF volume, what type of therapy is commonly used?
(For those with hypertension and edema)
Diuretic therapy
For pregnant clients who had swelling of her ankles due to increased hydrostatic pressure, they should do what?
Keep legs elevated and not stand for extended periods of time to decrease swelling in ankles.
Clients who have peripheral edema due to heart disease should wear _______________ _______________ to increase interstitial fluid pressure, thereby providing some resistance to the movement of fluid from the capillary to the interstitial space
supportive stockings
Edema and third-space fluid shifts are examples of what?
loss of intravascular fluid volume
Movement of body fluid between the Intracellular Fluid (ICF) and Extracellular Fluid (ECF) compartments, depends on what?
The ECF levels of water and of sodium
What is the primary solute in the ECF?
Sodium
What is the major regulator of sodium and water balance?
the amount of circulating blood volume
Our bodies strive to maintain __________ ____________ ___________ to effectively perfuse tissues, supplying them with nutrients and removing wastes.
adequate vascular volume
The Fluid Balance Receptors or Sensors pick up messages in the body about the adequacy of our circulating fluid volume.
True or False?
True
What type of receptors are located in the hypothalamus and keep track of the osmolality (concentration of the blood)?
Osmoreceptors
Where are osmoreceptors located?
In the hypothalamus
What are osmoreceptors responsible for?
Keeping track of the osmolality (concentration of the blood)
What type of receptors are located on the blood vessel walls and in the kidneys and measure the stretch in the vessel walls that is produced by blood volume and blood pressure?
Baroreceptors
Where the two places that are baroreceptors located?
on the blood vessel walls and in the kidneys
What are baroreceptors responsible for?
They measure the stretch in the vessel walls that is produced by blood volume and blood pressure
The body uses several mechanisms of fluid balance in response to messages from the osmoreceptors and baroreceptors including what 5 things?
Thirst, ADH, Sympathetic Nervous System, Renin-Angiotensin-Aldosterone System, and Natriuretic Peptides
What is the primary regulator of water intake?
Thirst
Normally, we drink without being “reminded” by the thirst mechanism.
True or False?
True
Sometimes, our bodies can experience unanticipated decreases of blood volume or increases in osmolarity, that alter the body to take what?
corrective action
When eating a lot of salty food, the thirst mechanism will prompt you to do what?
drink more
Thirst develops only with a large change in fluid volume or osmolarity.
True or False?
False
Thirst develops with even a small change in fluid volume or osmolarity
Other than thirst, what is the second mechanism of fluid regulation?
ADH (antidiuretic hormone/vasopressin)
Where is ADH made and then stored?
hypothalamus and posterior pituitary
What can the Hypothalamus can detect?
low blood volume or increased osmolality
What does the hypothalamus do after it detects low blood volume or increased osmolality?
send a signal to the posterior pituitary to release ADH
ADH acts on the kidney tubules to ________ ________ and therefore increases _________ ___________ and reduces serum osmolality
retain water and blood volume
Which nervous system responds to changes in arterial blood pressure and blood volume in several ways?
Sympathetic Nervous System
Sympathetic Nervous System responds to changes in arterial blood pressure and blood volume in several ways
By regulating the constriction or relaxation of the afferent and efferent arterioles in the kidney, what can be controlled?
The amount of glomerular filtrate can be controlled
When the Sympathetic Nervous System is stimulated, the ____________ _____________ will constrict therefore limiting the amount of blood flow to the kidney and ________________ glomerular filtration pressure
afferent arterioles and lowering
What does sympathetic activity regulates?
the reabsorption of sodium
Sympathetic Nervous System stimulation results in the release of what?
release of renin
What is the hormonal regulator of fluid balance?
Renin-Angiotensin-Aldosterone System
If circulating blood volume drops, there is less blood flow to the glomerulus, so less _______ ____________ ____________.
renal perfusion pressure
Juxtaglomerular cells in the kidney sense the reduced stretch of the afferent arteriole because of what?
reduced blood flow
Renin-Angiotensin-Aldosterone System (R-A-A-S) causes an increase in release of _______, which acts as an enzyme to convert _______________________ to _____________________
renin, angiotensinogen, andangiotensin I
Angiotensin I is converted to angiotensin II (the active angiotensin) by which enzyme?
ACE (angiotensin converting enzyme)
Angiotensin II (when activated) acts directly on kidney tubules to increase _____________ ________________ and stimulates the production of ___________________ in the adrenals
sodium reabsorption and aldosterone
Aldosterone works in the what parts of the kidney to promote exchange of sodium and potassium
distal tubule
Aldosterone works in the distal tubule of the kidney to promote exchange of sodium and potassium. Is sodium reabsorbed or lost?
reabsorbed
Aldosterone works in the distal tubule of the kidney to promote exchange of sodium and potassium. Is potassium reabsorbed or lost?
Lost
When sodium is reabsorbed, what does it bring with it that results in an increase in circulating blood volume?
Water
What provides a counterbalance to the activity of baroreceptors, ADH and the Renin-Angiotensin-Aldosterone System (R-A-A-S)?
Natriuretic Peptides
What are examples of Natriuretic Peptides? (What do they respond to?)
ANP and BNP (Respond to increased BP and volume)
Natriuretic Peptides Cells ANP and BNP respond to increased BP and volume and can cause the kidneys to do what?
increase sodium and water exertion
Natriuretic Peptides Cells ANP and BNP respond to increased BP and volume.
These cells can cause the kidneys to increase sodium and water excretion by:
- Suppressing renin levels
- Decreasing aldosterone release
- Causing vasodilation
True or False?
True
Infants have a lower percentage of body water than adults
True or False?
False
Infants have a higher percentage of body water than adults
Where is more than half of infants total body water found?
Extracellular compartment
Infants ingest and excrete a relatively higher daily water than who?
adults
Infants may exchange up to half of this daily extracellular Fluid and have a smaller reserve of body fluid than adults.
True or False?
True
Why is fluid exchange is greater in infants?
Because of their high metabolic rate
Infants are at risk for fluid imbalances because of the inability of infant’s immature kidneys to do what efficiently?
concentrate urine
Why do infants lose a relatively greater fluid loss through the skin than adults?
Because of their proportionally greater body surface area
Both infants and children have immature homeostatic regulating mechanisms therefore they cannot respond as efficiently as adults, to small changes in fluid balance.
True or False?
True
Aging kidneys experience a decrease in _______________ and a decrease in ___________
glomeruli and GFR (Glomerular Filtration Rate)
Who has a decreased ability to concentrate urine?
Infants and elderly
Elderly individuals are slower to respond to sodium and water imbalances, including having a decreased response to ________ and a decrease in secretion of _____________
ADH and aldosterone
The elderly have a reduction in total body water
True or False?
True
Thirst sensation decreases or increases with age.
Decreases
Fluid intake is not necessarily regulated by thirst, but can be associated with what?
Food intake
If an older adult is eating poorly it is possible that they are drinking poorly
Why are obese individuals at risk of fluid imbalances?
Their percentage of total body water is much less than that of a lean individual
(These individuals have less body water to lose)
Why are sick individuals at risk for fluid imbalance?
decreased intake of fluid
Who is at risk for fluid imbalance due to increase in fluid losses through fever, vomiting, or diarrhea?
sick individuals
In sick individuals, inflammatory response causes intravascular fluid loss due to increased capillary permeability.
True or False?
True
In sick individuals, when fluid is not where it is supposed to be, it can result in what?
dehydration
Accurate, ongoing assessment is vital in detecting fluid or electrolyte imbalance early.
True or False?
True
Understanding the reasons behind the signs and symptoms helps nurses know what changes are relevant and what interventions might be appropriate.
True or False?
True
What could occur if there is fluid volume deficit or the result of mouth breathing?
dry mouth
When checking for dehydration, the trick to look at areas where gums and cheeks meet to determine the difference.
In mouth breathing this area will be moist or dry?
Moist
When checking for dehydration, the trick to look at areas where gums and cheeks meet to determine the difference.
In fluid volume deficit this area will be moist or dry?
Dry
What is the elasticity of the skin that allows it to return to normal position after it has been pinched is a helpful assessment?
Skin Turgor
When addressing skin turgor, in individuals with fluid volume deficit, the skin flattens more slowly or more quickly after a pinch is released?
more slowly
When you check skin turgor, remember that the test measures not just interstitial fluid volume but what else?
skin elasticity
Older clients or clients with recent weight loss might show signs of decreased skin elasticity.
True or False?
True
Obese infants lose skin turgor, especially with fluid volume deficit.
True or False?
False
Obese infants maintain skin turgor even with fluid volume deficit
Because tissue turgor varies with age, nutritional status, race, and complexion, it is not the best indicator of imbalances.
True or False?
True
In infants, what is considered a reliable indicator of fluid volume?
decreased tearing
What is usually the earliest sign of decreased vascular volume?
tachycardia
When are alterations in pulse rate, regularity, and volume present?
in fluid/electrolyte imbalances
What bedside test can provide information about fluid volume status?
Blood Pressure
(Sometimes in suspected fluid volume imbalances, we take the blood pressure when client is lying and standing for accurate systolic and diastolic readings)
Edema (excessive amounts of interstitial fluid) will not become apparent until the interstitial volume has increased by at least how many litres?
2.5L
One must check that edema is what three things?
generalized, localized, and dependent
It is important to weigh patients with actual or suspected fluid balance problems.
True or False?
True
Rapid changes in weight reflect changes in what?
body fluid volume
Intake and output measurements
are more accurate than body weight measurements.
True or False?
False
Body weight measurements are more accurate than intake and output measurements
To minimize inaccuracies, clients should be weighed first thing in the morning (before breakfast, but after voiding) on the same scale and in similar clothing
True or False?
True
Normal urine output in an adult is what?
1000-2000ml/day OR 40-80ml/hour
Although it is very important to monitor urine output, it’s equally important to remember all other sources of measurable output and to recall that insensible losses in some patients can be considerable.
True or False?
True
It is important to know how much fluid a client is receiving from all sources
- Nurses should initiate careful intake and output records for any patient with a real or potential fluid or electrolyte imbalance.
True or False?
True
What measures the ability of the kidneys to concentrate urine?
Urine Concentration (specific gravity)
In fluid volume deficit, will the body conserves water or let water go?
Conserve water (so solutes are excreted in a small, concentrated urine volume)
High urine levels of unexpected solutes (such as glucose, albumin) will falsely elevate what?
specific gravity (urine concentration) readings
Some disturbances in body fluid or electrolyte imbalance will create central and/or peripheral effects that include what 4 symptoms?
Headache, anxiety, changes in Level of Consciousness, and twitching.
What accounts for most of the osmotic activity in the ECF?
Sodium (and chloride or bicarbonate anions that are associated with sodium)
Proportionate changes in sodium and water and disproportionate changes are known as what?
Isotonic
Isotonic changes can also be divided into two categories:
What are they?
Proportionate losses of sodium and water and Proportionate gains
When both sodium and water are lost, what type of fluid volume deficit exists?
an isotonic fluid volume deficit exists
When both sodium and water are lost, an isotonic fluid volume deficit exists
Plasma electrolyte concentrations remain unchanged but the circulating fluid volume has decreased
True or False?
True
When both sodium and water are lost, an isotonic fluid volume deficit exists
Plasma electrolyte concentrations remain unchanged but the circulating fluid volume has decreased
What are the top two reasons why this would this happen?
Inadequate Intake and Excessive Output
In the case of Inadequate Intake. A deficit of extracellular body fluid can occur for many reasons. Perhaps fluid intake has decreased, either because fluids are not available or because they are intentionally being withheld.
Perhaps the individual’s sensation of thirst is impaired.
True or False?
True
In the case of Excessive Output. Fluid lost through the skin due to what four things?
fever, exposure to heat, wounds or burns
In the case of Excessive Output. Fluid can be lost to circulation when it becomes trapped where?
in a third space (such as the peritoneum, intestine)
In the case of Excessive Output. Fluid is readily lost through the gastrointestinal tract— in one day, how much fluid is secreted into the gastrointestinal tract?
10L
(Most of this is usually reabsorbed in the ileum, but vomiting or diarrhea can result both in large losses and in increased secretion of fluid into the GI tract)
Fluid can be lost through the kidneys due to ____________,_____________,____________ that result in impaired sodium and water reabsorption
diseases, drug therapy, and diuretics
The body responds to small decreases in total fluid volume by initiating what?
Thirst (maybe - because thirst response can be unreliable response in elderly and not easily assessed in infants)
When fluid volume is lost from the body, there is a decrease in what?
body weight
1 Liter of water weighs how many kilograms
1 kilogram
Fluid volume deficit does not always result in a decrease in body weight
- If fluid is lost to the third space, it still contributes to body weight but not to what?
the functional fluid volume
When baroreceptors sense a decrease in vascular volume, they will send the message to the ________________ to initiate a compensatory secretion of ADH
pituitary
ADH causes increased reabsorption of __________ and ____________ with results in __________ urine output
water and sodium and decreased
As output decreases, urine is more concentrated and the specific gravity and osmolality rise or fall?
rise
When vascular volume decreases, fluid will move from the interstitial space, in an attempt to try to improve vascular volume.
True or False?
True
When tissues lose fluid, they lose what?
their resilience
When the blood volume declines, the blood pressure increases or decreases?
decreases
What is one of the early signs of fluid deficit?
postural hypotension (a drop in blood pressure on standing)
As Blood Pressure drops, heart rate will ____________ and pulse will become __________ and _________
increase and weak and thready
In severe volume depletion, the body experiences ____________________ with vascular collapse?
hypovolemic shock
As sodium and water are decreased, what two things become more concentrated?
red cells and Blood Urea Nitrogen (BUN)
Due to the fact that hypovolemia can cause renal damage and circulatory collapse, it is important to do what?
replace lost fluid promptly
When IV therapy is required, isotonic losses are replaced with isotonic fluids such as?
“normal” saline or lactated ringers’ solutions
Although replacing fluids is critical, it is also is just treating the symptoms.
It is important to do what in this case?
treat the cause (not only the symptoms )
When sodium and water are retained in proportion, what type of fluid volume excess results?
isotonic
Both Extracellular Fluid Compartments expand:
The Vascular Volume
The Interstitial Fluid Volume
True or False?
True
If there is an isotonic fluid volume excess it is unusual in healthy individuals because the body’s compensatory mechanisms for dealing with excess volume are usually sufficient to restore fluid balance.
True or False?
True
What can occur when the body is unable to eliminate appropriate amounts of fluid due to poor kidney function?
Hypervolemia
If the heart is unable to effectively pump, decreased blood flow to the kidneys will result in what?
fluid retention
What will an increase in the amount of sodium ingested result in?
water retention
The health care team can play a part in a client’s hypervolemia
If excessive amounts of IV fluids are given or if the fluids are given quickly, the body may be unable to manage the increase in what?
circulating volume
Changes in body weight can indicate what?
Fluid overload
Increased hydrostatic pressure from hypervolemia can result in what?
Edema
What can be caused by increase in vascular volume
Can see full, bounding pulse
Distended Neck Veins
What can be caused by fluid accumulation in the lungs?
Listen for crackles; watch for a productive cough
Respiratory Symptoms
In hypervolemia, blood urea nitrogen and hematocrit levels will increase or decrease?
decrease (when both are diluted)
What are the three ways to treat isotonic fluid volume excess?
Stop increasing the fluid volume, start decreasing the volume, and treat the cause
What are conditions in which sodium and water are gained or lost in their normal proportions?
Hypovolemia and hypervolemia
Sometimes fluid imbalances are not always proportionate
True or False?
True
Sometimes either sodium or water are lost or gained independently of each other, resulting in changes in sodium concentrations. What are these conditions known as?
hypernatremia and hyponatremia
What is defined as plasma concentration of sodium less than 135 mmol/L?
Hyponatremia
What are the two reasons that concentrations of sodium could drop?
Too little sodium in the ECF or too much ECF water
A deficiency of sodium can be the results of too little sodium intake; This is common in North American society.
True or False?
False
This is uncommon in North American society, where excessive sodium intake is a common risk for many health problems
Excessive loss of sodium is related to what?
renal problems or diuretic use
Sodium is also lost through sweating, GI losses, such as what?
vomiting, diarrhea, and nasogastric suctioning
Blood sodium can be diluted when there is _____ ________ ________ in the vascular space
too much fluid
If other osmotically active particles in the bloodstream increase intravascular osmotic pull, fluid will move into or out of the vessel (An example of this is hyperglycemia)?
Into the vessel
When water is retained, it is usually the fault of what?
of the kidneys
High levels of ADH results in what?
too much water retention
In the postoperative period, clients are given electrolyte-free IV fluids such as what?
Dextrose in Water (D5W)
Sometimes the high ADH levels are through inappropriate secretion - mixed up messages in the body. What is this syndrome known as?
SIADH (syndrome of inappropriate antidiuretic hormone)
Water retention can be caused by some medications (including several antipsychotic medications)
True or False?
True
What two populations is Hyponatremia is common in?
hospitals and in the elderly outpatient population
Manifestations of hyponatremia really depend on what?
the cause of the problem and the speed of onset
Decreased vascular osmotic pressure, hyponatremia results in fluid shifts from the extracellular space into the cells.
True or False?
True
When the brain swells, clients will have what?
Headaches
further swelling, there will be changes in level of consciousness and coma
Fluid shifts into the GI tract results in what?
diarrhea
Recall: sodium plays in the transmission of impulses in nerve and muscle fibres.
When sodium levels are too low, clients will experience what?
muscle cramping, weakness, fatigue, and tremors
It is important for members of the health care team to determine the cause of the client’s hyponatremia and fix it if possible.
True or False?
True
If there is a water excess:
- Clients will be placed on fluid restrictions.
- If it’s a medication that’s causing the water intoxication, that medication should be stopped.
- If the client is hypervolemic, it may be necessary to limit both water intake and salt intake until the cause of the problem has been determined and treated.
True or False?
True
If hyponatremia is severe, it is possible that the physician will order what?
oral or IV sodium replacements
It is important for nurses to monitor patients closely.
- You’ll want to monitor vital signs, neurological status, intake and output, and daily weight, all of which will provide important information about the client’s fluid balance status. And of course, you’ll monitor lab values as well.
True or False?
True
What is defined as a serum sodium concentration of more than 145 mmol/Litre?
Hypernatremia
What can high levels of sodium can be caused by?
too much sodium in the ECF or too little water
Hypernatremia usually is caused by too much sodium intake.
True or False?
False
Hypernatremia rarely is caused by too much sodium intake.
Increased sodium creates an increase in the osmolality of the blood which stimulates what?
thirst
Hypernatremia shouldn’t persist unless there is what?
no access to fluid
Rarely, the administration of IV fluids or of sodium bicarbonate in specific medical treatments will result in hypernatremia.
True or False?
True
More commonly, hypernatremia is caused by what?
water loss
Patients lose water through insensible losses through the skin or lungs when they experience what?
fever, heat stroke or respiratory illnesses
In hypernatremia is caused by water loss.
hypernatremia
Some clients lose extraordinary amounts of water through what?
osmotic diuresis
At the level of the kidney, loss of particles into the filtrate will cause a related loss of water.
True or False?
True
The manifestations of hypernatremia are all related to the increased osmolality of the blood but symptoms depend on _______ the osmolality is increased.
why
If problem is an increase in sodium, fluid will shift from the intercellular compartment to the vasculature because of osmotic pull.
This results in what type of cells?
shrunken cells
Shrunken brain cells are not happy cells. Your client will be restless, confused and weak.
If problem is an increase in sodium, fluid will shift from the intercellular compartment to the vasculature because of osmotic pull.
This results in what type of cells?
shrunken cells
Shrunken brain cells are not happy cells. Your client will be restless, confused and weak.
When water is lost in greater proportion than sodium, your client will also show signs of volume depletion such as?
dry mucous membranes and orthostatic hypotension
Hypernatremia: Manifestations
Lab values will show an increase in ____________ _______________ and an increase in osmolality
sodium concentration
Care must be taken to ensure that serum osmolality is corrected slowly.
A sudden decrease in osmolality would cause fluids to shift quickly to brain cells causing ____________ ____________ and potentially permanent neurological injury.
cerebral edema
Fluid volume status and the distribution of fluids between the intracellular and extracellular compartments depend on water and sodium balance.
True or False?
True
The body will always try to preserve blood volume so it can effectively do what?
nourish tissues
What type of fluid volume shifts involves both sodium and water losses or gains in equal proportion?
Isotonic Imbalances
What type of fluid volume shifts involves a fluid volume deficit or dehydration?
Isotonic Loss
What type of fluid volume shifts involves fluid volume excess?
Isotonic gain
What is the decrease in osmolality that occurs when there is proportionately too much water?
Hyponatremia
What is the increase in osmolality due to proportionately too little water?
Hypernatremia
What is the major intracellular cation and plays a major role in regulating many body functions?
Potassium
Particularly important is the role that potassium plays in regulating _______________ _________________, controlling the excitability of nerve and _______________ ___________ and the contractibility of muscles.
membrane potentials and muscle cells
When we look at manifestations of potassium imbalance, knowing the role it plays in the body will help you understand what to assess.
True or False?
True
What is the way we lose potassium primarily?
renal excretion
Normal concentration in cells — 140 - 150 mmol/L
ECF concentration — 3.5 - 5 mmol/L
True or False?
True
What is a decrease in plasma potassium levels below 3.5 mmol/Litre?
Hypokalemia
What is a reasonably common cause of low potassium levels?
an inadequate intake of potassium
Adults require at least ____________ of potassium a day to balance renal losses.
40 mmol
The elderly are at risk for inadequate potassium intake if they are unable to purchase, prepare, and eat potassium rich foods.
True or False?
True
________________ patients who are receiving IV fluids might have hypokalemia if they receive solutions that do not contain potassium.
Hospitalized
Potassium can be lost through the kidney either or when what is high?
aldosterone (due to diuretic)
Potassium is also normally lost through what?
GI tract
Movement of potassium from the extracellular space into the intracellular space will increase or decrease potassium levels?
decrease
What promotes movement of potassium into the cell as do a number of medications such as bronchodilators and decongestants?
Insulin
Most clients will not show signs of hypokalemia until potassium levels fall below ______________________ and signs are usually gradual in onset so detecting the problem might take some time.
3.0 mmol/Litre
When the kidneys try to conserve potassium, it creates an _____________ for them to concentrate urine.
inability
In the GI tract, potassium deficit alters normal peristalsis so clients may have what?
anorexia, nausea or vomiting
Decrease in smooth muscle activity can cause what?
constipation (or, in severe cases, paralytic ileus)
What system that shows the most serious, even life-threatening, effects of hypokalemia?
cardiovascular system
Too little potassium interferes with __________________ _______________ _______________ and _______________ so patients may experience postural hypotension and cardiac arrhythmias.
normal electrical activity and contractility
What is the best treatment for hypokalemia?
prevention
Patients at risk, particularly patients who are on potassium-wasting diuretics, should be taught to do ingest what?
high potassium content
Once a deficit in potassium has occurred, it is difficult to adequately treat with high potassium foods alone - therefore use what?
replacement therapy (oral/IV)
Nurses need to be aware of all precautions necessary when administering any potassium replacement.
- Too much potassium is also a big problem.
True or False?
True
What is defined as plasma levels of potassium in excess of 5.0 mmol/L?
Hyperkalemia
It is difficult to create hyperkalemia when treating low potassium levels with oral supplements because the kidneys will do what?
excrete any overload
If IV potassium-containing solutions are administered rapidly (especially in clients with impaired kidney function), what can result?
hyperkalemia
Hospitalized patients, potassium-containing solutions should not be started until the client’s _____________ function is adequate
kidney
A common cause of hyperkalemia is what?
decreased renal function (renal failure)
A decrease in aldosterone will cause __________________ of sodium with an accompanying decrease in elimination of potassium
elimination
Movement of potassium out of cells and into plasma will cause what?
hyperkalemia
Hyperkalemia signs are often not noticeable until plasma levels exceed 6.0 mmol/L.
True or False?
True
When hyperkalemia is present, clients will have weakness, dizziness and muscle cramps but might also have abnormal what?
sensation or paresthesia
The most serious problem associated with hyperkalemia is what?
Cardiac
With hyperkalemia, problems with conductivity, the heart rate may slow, ECG changes will occur, and if the excess is severe, ventricular fibrillation and cardiac arrest may occur.
True or False?
True
Treatment for hyperkalemia depends on how quickly the potassium rate has risen and how high it is.
True or False?
True
Sometimes treatment can be limited to restricting dietary potassium (i.e. Salt substitutes) OR discontinuing medications that promote potassium retention (i.e. Potassium sparring diuretics)
True or False?
True
If potassium levels require aggressive treatment — prescribe ________ _________________ which will remove potassium by exchanging sodium for potassium in the intestinal tract
oral solutions
In severe hyperkalemia with neuromuscular or ECG changes — clients may require more aggressive treatment that helps to move potassium back into the cells or to promote what?
renal excretion
In hyperkalemia, treatment involves what two things?
restricting intake and promoting excretion
What are the 3 important cations in the body?
Calcium, phosphorus, and magnesium are important cations in the body
What two things play an important role in regulating ECF levels of the cations?
Vitamin D and parathyroid hormone
What removes calcium from the ECF?
Calcitonin
Tutorial
Which of the following best defines third-spacing?
a) An accumulation of fluid within the vascular compartment
b) An accumulation of fluid in the intracellular compartment
c) An accumulation of fluid in the interstitial space
d) An accumulation of fluid within body cavities
d
Tutorial
What is normal ECF/ICF balance and exchange? First, Second, Third Spacing?
First Spacing
Tutorial
What is edema considered? First, Second, Third Spacing?
Second Spacing
Tutorial
What is an accumulation of fluid in transcellular compartment (e.g body cavities, joints, eye) and does NOT exchange with ECF (non-functional fluid). First, Second, or Third Spacing?
Third Spacing
Tutorial
Which of the following is the primary solute found in ECF?
a) Water
b) Sodium
c) Potassium
d) Bicarb
e) Albumin (found in vascular department; contributing to oncotic pressure)
b
Tutorial
50 year old moderately overweight male with a 35 year history of cigarette smoking. Recently diagnosed with HTN and type 2 DM.
Presented to the ER with fever lasting >24 hrs, difficulties breathing, and complaints of GI discomfort.
Your examination of Mr Jaune reveals epigastric tenderness and a slightly distended umbilicus. CBC indicates elevated WBCs.
Differential Dx from the attending physician is acute pancreatitis.
Which of the following best accounts for Mr. Jaune’s presenting signs/symptoms and lab findings?
a) Mr. Jaune is experiencing pulmonary edema, which accounts for his difficulties breathing (dyspnea)
b) Mr. Jaune is experiencing ascites, related to a lack of albumin synthesis
c) Mr. Jaune is experiencing portal hypertension secondary to liver damage
d) Mr. Jaune is experiencing third spacing as a result of increased vascular permeability
D
Tutorial
The attending physician orders IV fluids containing K+ to be delivered over a period of 4 hrs (300 ml total).
What complication associated with this intervention should the healthcare team monitor for?
a) Acute renal failure
b) Altered consciousness
c) Jugular venous distension
d) Cardiac arrhythmias
e) Pitting edema
d
Tutorial
A previously healthy 11 month old infant is
referred to PICU with a 3 day history of diarrhea
and vomiting.
Baby Blue has sunken eyes, a sunken fontanelle, and dry
mucous membranes. Pulse is rapid and difficult to palpate.
What fluid imbalance is Baby Blue most likely suffering from?
a) Isotonic fluid loss (sodium, potassium, and chloride)
b) Isotonic fluid gain
c) Hypernatremia
d) Hyperkalemia
a
Tutorial
Which of the following is most useful for assessing fluid balance in an infant?
a) Thirst
b) Skin turgor
c) Tearing
d) Urine concentration (Specific Gravity = SG)
e) Pulse pressure
c
Tutorial
A previously healthy 11 month old infant is
referred to PICU with a 3 day history of diarrhea
and vomiting.
Baby Blue has sunken eyes, a sunken fontanelle, and dry
mucous membranes. Pulse is rapid and difficult to palpate.
Which of the following interventions would be most appropriate to treat Baby Blue’s fluid imbalance?
a) Oral rehydration fluids
b) IV normal saline
c) IV D5W
d) IV colloids
e) Restrict all fluids
b
Tutorial
A 6 year old client enters the MUMC ED. His mother states that her son has been rapidly losing weight since they returned from Pakistan 4 weeks ago. She states that her son has complained of feeling unwell for several days, and has recently begun wetting the bed.
The triage nurse notes the following: appears lethargic; afebrile = NOT FEVERISH; dry mouth; HR 120; BP 110/70; capillary refill time of 5 seconds (not adequate perfusion in the periphery).
Urine is 4+ glucose with a ‘large’ ketone reading; lab results indicate plasma glucose at 32 mmol/L.
What is the likely cause of Praga Kahn’s sudden weight loss?
a) He acquired a GI infection in Pakistan resulting in vomiting, diarrhea, and fluid loss
b) He is losing fluid to third-spacing in the form of ascities, which is compressing his bladder
c) He is likely suffering from anorexia nervosa and in his starved state is producing ketones
d) He is experiencing increased osmotic diuresis resulting in abnormally rapid weight loss
D
D
Tutorial
A 6 year old client enters the MUMC ED. His mother states that her son has been rapidly losing weight since they returned from Pakistan 4 weeks ago. She states that her son has complained of feeling unwell for several days, and has recently begun wetting the bed.
The triage nurse notes the following: appears lethargic; afebrile = NOT FEVERISH; dry mouth; HR 120; BP 110/70; capillary refill time of 5 seconds (not adequate perfusion in the periphery).
Urine is 4+ glucose with a ‘large’ ketone reading; lab results indicate plasma glucose at 32 mmol/L.
Anticipating the plan of care, the nurse prepares to administer which type of intravenous (IV) infusion?
a) Potassium infusion
b) Rapid acting insulin infusion
c) 5% dextrose infusion
d) Normal saline infusion
d
Tutorial
Put the CDA CPG recommendations for the management of DKA in order: A. Avoid Hypokalemia B. Avoid Rapid decreasing OSM C. Fluids (NS) D. Search for cause E. Insulin
C, A, E, B, D
Tutorial
After consulting with an intensivist and nephrologist, the attending physician decides to continue IV NS, adding on a bolus infusion of 3% hypertonic saline & intermittent furosemide (Lasix).
How does this combo therapy help to correct the F&E imbalance?
a) The hypertonic solution replaces the lost water, while the diuretic promotes loss of excess salt.
b) The hypertonic solution corrects the salt imbalance, while the diuretic decreases total body water content.
c) The hypertonic solution helps to increase vascular oncotic pressure, while the diuretic promotes renal salt resorption.
d) These therapies would be ineffective as they act to cancel each other out!
B
Tutorial
If someone has hypernatremia and nothing else, what should be done?
Only restrict fluids and let your kidneys recooperate
