Week 6 - Fluid Balance and Circulation Flashcards
Fluid Compartments
1) Intracellular Fluid
2) Extracellular Fluid
1. Interstitial
2. Intravascular
3. Transcellular
Homeostatis
- Body’s maintenance of a stable internal environment
- Equilibrium is maintained by adjusting physiological processes
- Regulatory mechanisms: __________, _________, & __________ maintain composition, distribution & movement to maintain fluid & electrolyte balance
3 Types of Solution Movement
1) Osmosis
- movement of water across selectively permeable membrane from an area of HIGH concentration, to area of LOW concentration; based on
osmolality
2) Diffusion
- movement of particles across semi-permeable membrane from area of HIGH concentration, to area of LOW concentration, *remember from physiology–electrolytes require ACTIVE (or facilitated) diffusion, using ion pumps!
3) Filtration
- movement of fluid through a cell or vessel membrane due to hydrostatic pressure differences
- Hydrostatic pressure: pressing of water molecules outwards from a confined space, forces water to move from area of HIGH pressure to area of LOW pressure
What are the 3 ways in which fluid is regulated?
1) Hypothalamus
- Stimulate/inhibit desire to drink
2) Renin-Angiotensin
- Aldosterone System (RAAS)
- Decrease in perfusion to kidneys = renin release
- Renin converts angiotensinogen to angiotensin I in blood
- Angiotensin I converted to angiotensin II in lungs
- Angiotensin II = vasoconstriction, stimulate thirst, stimulate aldosterone to
retain water & Na
- Atrial Natriuretic Peptide (ANP) inhibits this system when in state of overload
3) Antidiuretic Hormone (ADH)
- Changes in blood osmolality stimulate ADH from pituitary
- ADH stimulates retention of water by kidneys
Fluid Volume Deficit
- Fluid Volume Deficit (FVD): decrease in intravascular, interstitial, and intracellular fluid
- Due to insufficient intake, excessive loss, or fluid shifts within the body (third spacing)
- Fluid deficit in intravascular space = difficulty perfusing body, systems activate to raise BP
- Excessive loss of body fluids
- Classify according to serum Sodium (Na) concentration
- Hypertonic loss: H20 loss > Na+ loss → ↑ serum Na+
i.e., early kidney disease = excessive dilute urine - Isotonic loss (Hypovolemia): H20 loss = Na+ loss → serum Na+ remains the same
i.e., hemmorage - Hypotonic loss: H20 loss AND excessive Na+ loss → ↓ serum Na+
i.e., excessive GI loss and H2O replacement only
S&S of Fluid Volume Deficit
- Restlessness, drowsiness, confusion
- Thirst, dry mucous membranes
- ↓ skin turgor and cap. refill
- ↑ pulse, ↓ CVP
- Postural hypotension
-↓ urine output - ↑ respiratory rate
- Weakness, dizziness
- Weight loss
Nursing Interventions for Fluid Volume Deficit
1) Correct Underlying Cause of Deficit
- Loss due to nausea & vomiting: anti-emetics
- Loss due to diarrhea: _____________________________________
- Loss due to diaphoresis: dry skin well (pat dont rub), change sheets frequently
- Loss due to fluid shift: albumin (plasma poteins)
- oral route is better than IV route for hydration bc IV can cause fluid volume overload
2) Replace fluids and electrolytes
- Oral rehydration: preferred if tolerated
- IV rehydration: Isotonic solutions preferred unless severe electrolyte
imbalance
- Provide oral or IV therapy according to physician orders
- General Principals:
✓Use Isotonic fluids for isotonic fluid losses
✓Use hypotonic fluids for hypertonic losses
✓Use hypertonic fluids for hypotonic losses
3) Assess for inadequate perfusion & prevent hypovolemic shock
- Fatal if left untreated
- Cause: Decreased intravascular fluid volume
- External fluid losses: Fluid is lost externally
Internal fluid losses: Fluid shifts between intravascular and interstitial compartments
(third spacing!)
General Shock Symptoms
Compensatory
- Normal BP
- ↑ HR
- ↑ RR
- Blood shunting to
vital organs
- Pale skin
- Hypoactive bowel
sounds
- ↓ Urinary Output
- Confusion
Progressive
- ↓ BP
- ↓ LOC
Refractory/Irreversible
- Severe and permanent organ
damage leading to death
* When you see this
combination of vital signs,
you need to immediately
be assessing for SHOCK!
Pathophysiology of Hypovolemic Shock
1) Hypovolemia = low blood volume (not enough fluid)
2) ↓ Venous return = less blood returning to the heart
3) ↓ Preload = less blood in the heart
4) ↓ CO = less blood being pumped by heart/minute
5) Hypotension = not enough blood being bumped = ↓ BP
6) Tissue Hypoxia = ↓ BP means tissues are not being perfused properly
7) organ dysfunction = tissues in organs do not receive enough oxygen and start to fail
8) Multiorgan failure
Fluid Volume Excess
- Fluid Volume Excess (FVE): fluid excess in intravascular space
- Results when fluid is retained in the body
- Due to fluid overload (excessive intake), abnormal retention (ex: heart
and kidney failure) - Fluid overload in intravascular space = raise BP, stress on systems
Signs & Symptoms of Fluid Volume Excess
- ↑HR, bounding pulse
- ↑ BP
- Distended veins
- Dysrhythmias
- ↑RR
- Dyspnea, crackles on
auscultation - Confusion
- Headache
↓ LOC → Coma - Muscle Spasms (r/t electrolytes)
- ↑ urinary output (if kidneys
functioning) - Cool, pale skin
- Edema
- ↑ Bowel sounds and motility
- Diarrhea
- Weight gain
Nursing Interventions for Fluid Volume Excess
1) Prevention- identify patients at risk
- dietary, fluid restrictions
- monitor daily weights
- How much weight gain is too much: (2-3 lbs/ 24 hrs, 5lbs in week = concerning increase)
2) Correct/manage underlying cause
3) Restore fluid balance & replace electrolytes
- Therapies to eliminate fluid from body
-Diuretics support kidneys to excrete fluid from intravascular space
-Consider: Kidney function – if kidneys have insufficient function, diuretics are contraindicated, may need dialysis
- Monitor electrolyte levels, particularly with diuretic use, replace as needed
Pharmacological Interventions: Furosemide (Lasix)
Therapeutic Class: Diuretic
Pharmacy Class: Loop Diuretic
Action:
- increases renal excretion; mobilize excess fluid and decrease BP
Side Effects:
- Dizziness
- Headache
- Hypotension
- electrolyte imbalance
(hypokalemia)
Caution: contraindicated with impaired kidney function
Nursing Considerations
- Older clients=Falls risk
- electrolyte imbalance
- Consider preexisting kidney function and impact on kidneys
- Monitor weights: avoid taking at night (*nocturnal urination may disrupt sleep)
Pharmacological Interventions: Hydrochlorothiazide
Therapeutic Class: Antihypertensives
Pharmacologic Class: Thiazide Diuretic
Action: lower BP by reducing fluid volume
Side Effects:
- Dehydration
- dizziness
- headache
- hypotension/ortho hypo
- electrolyte imbalances (hypokalemia, hyponatremia)
Caution: contraindicated with impaired kidney function
Nursing Considerations:
- Risk for hypotension
- monitor electrolytes
- daily wts
- I/O (what is this??)
- falls risk with older adults
- monitor kidney function
Pharmacological Interventions: Spironolactone
Therapeutic Class: Antihypertensives
Pharmacologic Class: Potassium Sparing Diuretic
Action: lower BP by reducing fluid volume
Side Effects:
- Dizziness
- headache
- hypotension/ortho hypo, electrolyte imbalances
(hyperkalemia)
- photosensitivity
- N/V/D
Caution: contraindicated with later stage kidney function
Nursing Considerations:
- Risk for hypotension
- monitor electrolytes
- daily wts
- I/O
- falls risk with older adults
- monitor kidney function
Function of Electrolytes
- Substance dissolved in water that can conduct electricity
- Carry positive or negative charge
- Control fluid movement between fluid compartments
- Conduct messages on nerves and muscles
- Aid in endocrine secretion (remember insulin & K+)
- Buffer fluids
- Electrolyte intake from food/drink, absorbed as needed by kidneys
- Exit the body via bodily fluids
Sodium (Na+)
- Reference range 135-145 mEq/L
- Filtered & excrete by kidneys
- Sodium determines where water is retained, excreted or moved to
maintain blood pressure
Quick Summary:
- Too little Na+ in blood, water rushes into the cells to balance & cells swell
- Too much Na+ in blood, water leaves cells & cells shrink
2 Types of Sodium Imbalances
1) Hyponatremia (<135 mEq/L)
2) Hypernatremia (>145 mEq/L)
Signs of Hyponatremia
- Decreased serum osmolality
- Decreased hematocrit
- Weight loss
- Weakness
- Muscle cramping, twitching
- Headache
- Anxiety, lethargy, coma
- Nausea, vomiting, diarrhea
Management of Hyponatremia
If both sodium and water is lost:
- Hyponatremia and fluid deficit
- Replace with isotonic fluid for non severe, and hypertonic solutions if severe (<120 mEq/L)
- Monitor for fluid volume overload during rehydration!
If sodium lost with normal-excess fluid
- Excrete fluid to balance
- Diuretics to promote fluid excretion
Signs of Hypernatremia
- Increased serum osmolality
- Increased hematocrit
- Weight gain
- Thirst, urinary output changes
- Dry skin and mucous membranes,
decreased turgor - Headache, restlessness, seizure, coma
- Tachycardia
Management of Hypernatremia
If high with decreased fluid volume:
- ________________ fluid administration
If sodium high with normal-excess fluid:
- Diuretics to promote sodium excretion
- Na+ imbalances must be corrected slowly to prevent cerebral edema
Potassium K+
- Reference range 3.5- 5 mEq/L
- Maintains fluid balance in the cells
- Contributes to intracellular osmotic pressure
- Direct effect on excitability of nerves and muscles
- Skeletal, cardiac, and smooth muscle contraction
- Regulates glucose use and storage
2 Types of Potassium Imbalances
1) Hypokalemia (<3.5 mEq/L)
2) Hyperkalemia (>5 mEq/L)
Signs of Hypokalemia
- Confusion, depression, lethargy
- Respiratory arrest
- Polyuria, polydipsia
- Constipation, decreased bowel sounds
- Fatigue
- Muscle cramps, muscle weakness, poor tone, progression to paralysis
- Dysrhythmias, irregular pulse, ECG changes
Management of Hypokalemia
- Potassium replacement
medications - IV Medications: Potassium
- SLOW administration
- DO NOT GIVE IV PUSH
- Monitor for hyperkalemia
- Cardiac monitoring
- Falls prevention r/t muscle
weakness
Signs of Hyperkalemia
- Irritability, anxiety
- Abdominal cramping, diarrhea,
increased bowel sounds - Muscle twitching, progresses to muscle weakness, then paralysis
- Bradycardia, hypotension, irregular pulse, ECG changes
Management of Hyperkalemia
- Potassium excreting medications
- Calcium gluconate
- Kayexalate
- Diuretics
- Insulin / glucose admin
- Cardiac monitoring
- Falls prevention r/t muscle
weakness
Types of IV Fluids
1) Hypotonic
- > LOW concentration of solute compared
to body fluids
- fluid moves into cell expands
- outside < inside
2) Isotonic
- = Equal concentration to body fluids
- cell fluid remains constant
- outside = inside
3) Hypertonic
- < HIGH concentration of solute compared
to body fluids
- fluid moves out of cell = cell shrinks
- outside > inside
** LOOK AT CHART**
IV Access: Peripheral IV (Vein in Extremity)
- Easy to access
- Easy to monitor
- Rapid infusion
- Short term therapy only
- Risk of phlebitis
- Risk of infiltration
- Risk of infection
- Easily irritated by caustic
or irritating solutions
IV Access: Central Access (Large vein leading to the superior vena cava)
- Easy to access
- Rapid/large volume infusion
- May be used to obtain blood samples
- May be used for long term therapy
- Less irritated by caustic or irritating solutions
- Requires more skill & time to insert
Greater risk of :
-Infection (sepsis)
-Pneumothorax, perforation of
surrounding organs
-Air embolism
-Thrombus formation
IV Access: Peripherally Inserted Central Catheter
(Peripheral vein to the superior vena cava)
- Long term therapy
- Less risk of thrombus formation
- Less risk of phlebitis
- Less irritated by caustic or
irritating agents - Requires time & skill to insert
- Difficult to insert if bruising or
scarring from earlier
venipunctures - Complications: catheter
occlusion, phlebitis
Components of Blood
Plasma - 55%
1. Protein (albumin, globulin, fibrinogen) - 7%
2. Water - 91%
3. Other Solutes (ions, waste, nutrients, gases) - 2%
Formed Elements - 45%
1. Platelets -
2. Leukocytes (neutrophils, lymphocytes, monocytes, eosinophils, basophils) - smallest portion
3. Erthrocytes - biggest portion
Complete Blood Count
Red Blood Cells RBC
- 4.00 - 5.10 x 1012/L
Hemoglobin HGB
- 140 - 180g/L (M)
- 120-160g/L (F)
- Hgb: protein that
carries O2
l- ow=anemia
Hematocrit Hct
- 42 – 54% (M)
- 37 - 47% (F)
- Hct: % by volume of
RBC low-fluid overload,
- high=dehydration
White blood Cells WBC
- 4.0 - 11.0 x 109/L
- high=infection
- low=impaired
immunity
Plateletes Plt
- 150 – 400 x 109/L
- low=lower clotting ability =more bleeding
INR (PT, PTT i think)
- 0.9-1.1
- Clotting times, high
values=lower clotting
ability=more bleeding
Red Blood Cells
- Reference range: Women: 4.2–5.4 × 1012/L, Men: 4.7–6.2 × 1012/L
- Erythropoietin (secreted by kidneys) stimulated RBC production by bone marrow
- High RBC= Erythrocytosis
- Occurs with increased erythropoietin or chronic hypoxia (remember our class on COPD)
- Low RBC= anemia
- Occurs with loss (bleeding) or destruction of RBCs, decreased erythropoietin or
bone marrow suppression
Hemoglobin
- Reference range: Women: 120–160 g/L, Men: 140–180 g/L
- Component of RBC that
transports oxygen - Must interpret in relation to Hct. If both LOW may just be diluted in ++ fluid
- High- not common
- Low- anemia
- Occurs with loss (bleeding) or destruction of RBCs, decreased
erythropoietin or bone marrow suppression, problems with iron
Hematocrit
- Reference range: Women: 0.37–0.47, Men: 0.42–0.54
- Relative RBC percentage in proportion to plasma volume
- Measure of fluid status
- High Hct- fluid deficit. RBCs very concentrated in lack of fluid
- Low Hct- fluid overload. RBCs very diluted or loss of overall RBCs (blood loss, RBC destruction, bone marrow suppression)
White Blood Cells
- Reference range: 4-11 X 109
/L - Measure of overall immunity & infection-fighting capacity
- WBC differential- different types of WBC (Neutrophils, Eosinophils, Basophils, Lymphocytes, Monocytes)
- High WBC- leukocytosis, usually indicative of infection
- Low- leukopenia, usually due to immunosuppression
Platelets (Thrombocytes)
- Reference range: 150-450 X 109 /L
- Important in coagulation (clot formation)
- Formed in bone marrow, stored in spleen
- High- thrombocytosis, risk for inappropriate clotting
- Low- thrombocytopenia, risk for bleeding
Clotting
- INR
- Reference Range: 0.9-1.1
- Measure of time for clot to form
- HIGH- blood takes longer time to
clot, bleeding risk - Altered by certain anticoagulants
(increases) - Low- blood clots quickly, clotting risk
Clotting Cascade
1. Vasoconstriction
2. Formation of Platelet Plug
-Adhesion
-Activation and Secretion
-Aggregation
3. Formation of Fibrin Clot
-Clotting factors in blood [12
proteins called factors (Roman
numeral)] work together to make fibrin threads woven into the platelet plug
