Week 1 Fluid Imbalances Chapter 10 and Recorded too

Question 1

Homeostasis: ‘everything in balance’

Answer 1

Body is always trying to achieve homeostasis
Fluids & electrolytes kept within narrow limits of
normal
Body fluids are constantly moving to maintain
composition of fluids and electrolytes
Various disease processes can affect these
balances so it is important for nurses to be astute
and carefully monitor for any changes

Question 2

Water uses in the body

Answer 2

Metabolic reactions
Transport
Lubricant
Insulator
Body temperature

Question 3

Fluid Gains

Answer 3

• Healthy people gain fluids by
drinking and eating
• Daily intake & output of water are
roughly equal in healthy individuals

Question 4

Fluid Losses

Answer 4

Kidney: urine output of 1mL/kg/hr
• Skin loss: sensible due to sweating and insensible due to fever, exercise,
and burns
• Lungs: 300 mL everyday, greater with increased RR
• GI tract: large losses due to diarrhea and fistulas

Question 5

Factors affecting water balance

Answer 5

• Age
• Sex
• Body habitus
• Temperature
• Disease state

Question 6

Gerontologic Considerations

Answer 6

• Clinical manifestations of imbalance may be subtle
• Fluid deficit may cause delirium
• LOC
• Decreased cardiac reserve
• Reduced renal function
• Dehydration is common
• Age-related thinning of the skin and loss of strength and elasticity

Question 7

Fluid Status

Answer 7

• Approximately 60% of typical adult is fluid
• Varies with age, body fat, gender
• Intracellular fluid (fluid in cells)
• 2/3 of body fluid, skeletal muscle mass
• Extracellular fluid (fluid outside cells)
• Intravascular: plasma, erythrocytes, leukocytes, thrombocytes
• Interstitial: lymph
• Transcellular: cerebrospinal, pericardial, synovial

Question 8

Osmolality

Answer 8

Concentration of solutes in body
fluid
• Normal Serum: 280-295
mOsm/kg
• Osmolality of urine ranges from
100-1300 mOsm/kg
13

Question 9

The osmolality of the fluid surrounding cells
affects them

Answer 9

• Isotonic
• Fluids with the same osmolality
• Hypotonic (hypoosmolar)
• solutes are less concentrated than the cells
• Hypertonic (hyperosmolar)
• solutes are more concentrated than the cells

Question 10

Body’s Regulation of Fluid

Answer 10

• Osmosis: water moves from an area of low solute concentration to area of
high solute concentration
• Movement of fluid through capillary walls depends on
• Hydrostatic pressure: exerted on walls of blood vessels
• Osmotic pressure: exerted by proteins in plasma
• Direction of fluid movement depends on differences in hydrostatic and
osmotic pressure

Question 11

Osmosis

Answer 11

Movement of fluid (water)
across semipermeable
membrane from less
concentrated solution to more
concentrated solution
• Membrane does not allow
solutes to cross so only fluid
moves

Question 12

Hydrostatic pressure

Answer 12

• Blood pressure generated by heart contraction
• Increases vascular hydrostatic pressure
• pushes water from vascular system into interstitial space and
• Inhibits fluid from moving back into the vascular spaces

Question 13

Osmotic pressure

Answer 13

• Protein molecules (albumin) in plasma attract water, pulling fluid from the
tissue spaces into the vascular space.
• Administering colloids or hypertonic solutions increases osmotic pressure
and draws fluid from interstitial spaces into plasma

Question 14

Fluid shifts

Answer 14

• Fluids can shift from plasma spaces to interstitial spaces, due to:
• Increase in venous hydrostatic pressure
• Increase in interstitial oncotic pressure
• Decrease in plasma oncotic pressure
• Result is second or third spacing
Fluid shifts
• Decrease interstitial shifts by:
• Reducing venous hydrostatic pressure
• Drawing interstitial fluid into plasma
• Administer colloids, mannitol,
hypertonic solutions
And/or
• Increase tissue hydrostatic pressure
• Wearing elastic stockings (TED hose) is a
therapeutic application of this effect

Question 15

Fluid spacing

Answer 15

• First spacing
• Normal distribution
• Second spacing
• Abnormal accumulation of interstitial fluid (edema)
• Third spacing
• Fluid is trapped where it is difficult or impossible for it to move
back into cells or blood vessels (ascites)

Question 16

Regulation of Water Balance: Renal regulation

Answer 16

• Kidneys are primary organs for regulating fluid & electrolyte balance by
adjusting urine volume
• Typical UOP 1mL/kg/hr
• Selective reabsorption of water and electrolytes
• Renal tubules are sites of action for:
• ADH (antidiuretic hormone)
• Aldosterone

Question 17

Regulation of Water Balance:
Hypothalamic-pituitary regulation

Answer 17

• Osmoreceptors in hypothalamus sense changes in body fluid
• Fluid Deficit
• Simulates thirst
• Triggers release of ADH
• Fluid Excess (Decreased plasma osmolality)
• Suppresses release of ADH

Question 18

Regulation of Water Balance:
Adrenal cortical regulation

Answer 18

• Releases hormones to regulate water and electrolytes
• Glucocorticoids
• Cortisol
• May cause Na & fluid retention
• Mineralocorticoids
• Aldosterone
• Causes Na retention and K+ excretion
• Water is retained with Na

Question 19

Significance of Fluid Balance:
Renin-Angiotensin II Pathway

Answer 19

• Blood (plasma) volume and intracellular fluid most important to keep in
balance
• Kidneys are major regulator of water and Na balance; maintain blood
and perfusion pressure to all tissues/organs
• Kidneys secrete renin when they sense low blood volume, blood pressure,
or Na

Question 20

Clinical Application - RAAS

Answer 20

Kidneys sense low
perfusion and
secrete renin
Renin converts
angiotensinogen
into angiotensin I
Angiotensin I then
converted by
angiotensin-
converting
enzyme (ACE)
into
Angiotensin II
•Powerful
vasoconstrictor
•Stimulates adrenals to
release aldosterone

Question 21

ACE Inhibitors

Answer 21

• Disrupt RASS by reducing amount of ACE produced
• With less angiotensin II
• less vasoconstriction and reduced peripheral resistance
• Greater excretion of water and Na in urine
• By blocking angiotensin II receptors, blood pressure lowers

Question 22

Regulation of Water Balance
Cardiac regulation

Answer 22

• Natriuretic peptides are antagonists to the RAAS
• ANP & BNP produced by cardiomyocytes in response to increased atrial
pressure and/or high Na levels
• They suppress secretion of aldosterone, renin, and ADH to promote
excretion of Na and H2 O to decrease blood volume and pressure

Question 23

Regulation of Water Balance
Gastrointestinal regulation

Answer 23

• Oral route accounts for most water intake
• Small amounts of water are eliminated by gastrointestinal tract in feces
• Diarrhea and vomiting can lead to significant fluid and electrolyte loss

Question 24

Fluid Imbalances

Answer 24

• Imbalances occur to some degree in most patients with major illness/injury
because illness disrupts normal homeostatic mechanism

Question 25

Fluid Volume Imbalances

Answer 25

• Dehydration
• Fluid volume deficit (FVD): hypovolemia
• Fluid volume excess (FVE): hypervolemia

Question 26

Dehydration

Answer 26

• Not the same as FVD
• Loss of water alone, with increased serum sodium levels
• Primarily pure water loss common in:
• Elderly
• Children
• Confused
• Overexertion
• Mild dehydration is corrected by oral consumption; consider sports drinks

Question 27

Fluid Volume Deficit (hypovolemia)

Answer 27

• May occur alone or in combination with other imbalances
• Extracellular fluid loss exceeds intake ratio of water
• Electrolytes lost in same proportion as they exist in normal body fluids

Question 28

Possible Causes of FVD

Answer 28

• Abnormal fluid losses
• Vomiting, diarrhea, sweating, GI suctioning
• Decreased intake
• Nausea, lack of access to fluids
• Third-space fluid shifts
• Due to burns, ascites
• Additional causes
• Diabetes insipidus, adrenal insufficiency, hemorrhage, trauma

Question 29

Fluid Volume Excess (hypervolemia)

Answer 29

• Isotonic expansion of the ECF caused by the abnormal retention of water
and sodium in approximately the same proportions in which they
normally exist in the ECF
• Secondary to an increase in the total body sodium content

Question 30

Possible causes of hypervolemia

Answer 30

• Heart failure
• Renal injury or failure
• Liver failure (cirrhosis)
• Excessive intravenous (IV) solutions and/or blood transfusions
• Excessive oral sodium intake
• Abnormal retention of fluids and sodium
• Fluid shift increasing intravascular volume
• interstitial-to-plasma fluid shift

Question 31

PO Fluid Administration
Used to correct mild
fluid and electrolyte
deficits

Answer 31

• Water
• Glucose
• Potassium
• Sodium
• Commercial oral
rehydration solutions (Sports
Drinks)

Question 32

Parenteral Fluid Administration

Answer 32

• Colloids and Crystalloids
• types of fluids that are used for
fluid replacement, often
intravenous

Question 33

Colloids

Answer 33

• Stays in vascular space and increases osmotic pressure & pulls fluid into
vascular spaces
• Sometimes referred to as volume or plasma expanders
• Examples:
• Human plasma products (albumin, fresh frozen plasma, blood)
• Semisynthetics (dextran and starches, Hespan)

Question 34

Crystalloids

Answer 34

• Crystalloids: solutions (e.g. saline) with small molecules, which can move
around easily when injected into the body.
• Examples include:
• 0.9% NaCl – NS (Isotonic)
• Lactated Ringers – LR (Isotonic)
• 0.45% NaCl – ½ NS (hypotonic)
• 3% NaCl (hypertonic)
• 5% Dextrose in water – D5W (both isotonic & hypotonic )

Question 35

Crystalloids: Intravenous Fluids (IVF)

Answer 35

• Purposes
• Maintenance (MIV)
• Replacement
• Types of fluids categorized by tonicity
• Hypotonic
• Isotonic
• Hypertonic

Question 36

Hypotonic (154 mOsm/L)

Answer 36

• 0.45% NaCl
• Contains more water than electrolytes
• Pure water lyses RBCs
• Never inject sterile water w/o additives into a vein
• Moves water from ECF to ICF by osmosis
• Usually a maintenance fluid or replacement
• Monitor for changes in mentation

Question 37

Isotonic (275-308 mOsm/L)

Answer 37

• 0.9% NaCl, D5W*, and Lactated Ringer’s solution (LR)
• Expands only ECF
• No net loss or gain from ICF
• Ideal to replace ECF volume deficit
• Also used as MIV or replacement

Question 38

Hypertonic (1,030mOsmol/L)

Answer 38

• D5 ½ NS; D10W; 3% saline
• Initially expands and raises the osmolality of ECF
• Require frequent monitoring of
• Blood pressure
• Lung sounds
• Serum sodium levels

Question 39

Fluid Volume Deficit (hypovolemia)

Answer 39

Extracellular fluid loss exceeds intake ratio of water
Electrolytes lost in same proportion as they exist in normal body
fluids

Question 40

Clinical manifestations: Hypovolemia

Answer 40

hypotension
tachycardia
tachypnea
pale skin
concentrated urine
lethargy
increased thirst
weakness
dizziness
weight loss
seizures
coma
Skin turgor, capillary refill, and urine output are all
decreased

Question 41

Fluid Volume Deficit—Nursing Management

Answer 41

Fluid Volume Deficit—Nursing Management
• I&O at least every 8 hours, sometimes hourly
• Daily weight
• Vital signs closely monitored
• Skin and tongue turgor, mucosa, urine output, mental status
• Measures to minimize fluid loss
• Administration of oral fluids
• Administration of parenteral fluids

Question 42

Hypovolemia Treatment

Answer 42

• Oral route preferred
• Isotonic IV solutions
• 0.9% NS
• LR
• Blood products
• Hypertonic IV solutions*

Question 43

Fluid Volume Excess (hypervolemia)

Clinical manifestations: Hypervolemia

Hypervolemia Treatment

Hypervolemia Nursing Management - Nursing
Implementation

Answer 43

Fluid Volume Excess (hypervolemia)
Isotonic expansion of the ECF caused by the abnormal retention of
water and sodium in approximately the same proportions in which
they normally exist in the ECF

Clinical manifestations: Hypervolemia

hypertension
pulmonary edema
Dyspnea / SOB
crackles
bounding pulse
peripheral/sacral edema
S3 heart sound
headache
increased UOP
JVD (jugular venous distention)
paroxysmal nocturnal dyspnea
Weight gain is the most consistent manifestation of fluid volume changes

Hypervolemia Treatment

• Remove fluid while maintaining adequate electrolyte composition
and/or osmolality of ECF
• Loop diuretics: Furosemide, Bumetanide, Torsemide
• Hydrochlorothiazide, spironolactone
• Fluid restriction
• Restrict sodium intake
• Aquapheresis
• Removes excess salt and water from the body

Nursing Management - Nursing
Implementation
I & O
Daily weights
Monitor VS
Assess respiratory changes/lung
sounds
Assess cardiovascular status
Monitor edema
Monitor lab values
Skin assessment (turgor, color,
temperature)

Question 44

Lymphatic system

Answer 44

• The lymphatic system is a part of the immune system and vital for immune
function.
• The lymphatic system helps move fluids between bodies plasma spaces
and interstitial spaces

Question 45

Hypervolemia (FVE)

Conditions that cause excess fluids (FVE)

Answer 45

• Expansion of ECF caused by abnormal retention of water & Na in the
extracellular spaces

Conditions that cause excess fluids (FVE)
• Excessive Na intake
• Medication side effects
• Congestive heart failure
• Cirrhosis
• Kidney disease
• SIADH
• Pregnancy
• Excess IV fluid

FVE Labs (values typically decrease)
• Serum osmolality
• Hematocrit
• BUN
• Na & K+
• Urine specific gravity

Question 45

Hypervolemia (FVE)

Conditions that cause excess fluids (FVE)

FVE Labs (values typically decrease)

Hypervolemia Treatment

Answer 45

• Expansion of ECF caused by abnormal retention of water & Na in the
extracellular spaces

Conditions that cause excess fluids (FVE)
• Excessive Na intake
• Medication side effects
• Congestive heart failure
• Cirrhosis
• Kidney disease
• SIADH
• Pregnancy
• Excess IV fluid

FVE Labs (values typically decrease)
• Serum osmolality
• Hematocrit
• BUN
• Na & K+
• Urine specific gravity

Hypervolemia Treatment
• Remove fluid while maintaining adequate electrolyte composition or
osmolality of ECF
• Diuretics
• Fluid restriction
• Restrict sodium intake
• Aquapheresis (Ultrafiltration)
• Removes excess salt and water from the body
• Aquapheresis Video

Question 46

Hypovolemia

Conditions that cause fluid volume deficit (FVD)

Hypovolemia Treatment

Answer 46

Hypovolemia
• a state or condition where the fluid output exceeds the fluid intake. It
occurs when the body loses both water and electrolytes from the ECF in
similar proportions.

Conditions that cause fluid volume deficit (FVD)
• Abnormal fluid losses
• Vomiting, diarrhea, sweating, GI suctioning
• Decreased intake
• Nausea, lack of access to fluids
• Third-space fluid shifts
• Due to burns, ascites
• Additional causes
• Diabetes insipidus, adrenal insufficiency, hemorrhage
• Polyuria
• DKA, Diabetes Insipidus, overuse of diuretics

Hypovolemia Treatment
• Correct the underlying cause and replace water and electrolytes
• Oral route preferred
• Isotonic IV solutions
• 0.9% NS
• LR
• Blood products

Question 47

Crystalloids: Intravenous Fluids (IVF)

Answer 47

Crystalloids: Intravenous Fluids (IVF)
• Purposes
• Maintenance (MIV)
• Replacement
• Types of fluids categorized by tonicity
• Hypotonic
• Isotonic
• Hypertonic

Question 48

Hypotonic (Osmolality: 154)

Answer 48

Hypotonic (Osmolality: 154)
• 0.45% NaCl
• Contains more water than electrolytes
• Moves water from ECF to ICF by osmosis
• Usually a maintenance fluid or replacement
• Contraindicated in head injuries
• Monitor for changes in mentation

Question 49

Isotonic (Osmolality: 275 – 308)

Answer 49

Isotonic (Osmolality: 275 – 308)
• 0.9% NaCl, D5W*, and Lactated Ringer’s solution (LR)
• Expands only ECF
• No net loss or gain from ICF
• Ideal to replace ECF volume deficit
• Also used as MIV or replacement

Question 50

Hypertonic (Osmolality: 1030)

Answer 50

Hypertonic (Osmolality: 1030)
• D5 ½ NS; D10W; 3% saline
• Initially expands and raises the osmolality of ECF
• Treatment of cerebral edema and severe, symptomatic hyponatremia
• Require frequent monitoring of
• Blood pressure
• Lung sounds
• Serum sodium levels

Question 51

What are the major differences between
hypovolemia and third-space fluid shift.

Answer 51

• The major difference is the final location of the fluid:
• Hypovolemia: Interstitial fluid is forced into the intravascular space; fluid
loss can be detected through decreased patient weight
• Third-space fluid shift: Body fluid shifts and is trapped in transcellular
compartments, unavailable for use
• fluid loss cannot be detected through decreased patient weight.