Week 1: Fluid and Electrolyte Balance I Flashcards
Fluid Compartment: Intracellular
- fluid within the cells
- 2/3 of body fluid (primarily in muscle mass)
Fluid Compartment: Extracellular
Fluid outside the cells
1/3 of body fluid
Transports electrolytes, enzymes and hormones
intravascular
Fluid within the blood vessels
Contains plasma (half of total blood volume)
Interstitial
Contains fluid that surrounds the cell
11-12 L in adults
Lymph fluid
Transcellular
Smallest space
1L in adults
Cerebrospinal, pericardial, synovial, intraocular, pleural fluids, sweat, digestive secretions
Third Spacing
loss of ECF into a space that does not contribute to equilibrium
What are the signs and symptoms of Third Spacing?
decreased urine output (despite adequate intake), increased heart rate, decreased blood pressure, decreased central venous pressure, edema, increased body weight, imbalanced intake and output (I&O)
Symptoms can look as if the patient is retaining fluid but are presenting as dehydrated
Caused by: intestinal obstruction, pancreatitis, crushing traumatic injuries, bleeding, peritonitis, major venous obstruction
Cations
sodium, potassium, calcium, magnesium, hydrogen ions
Anions
chloride, bicarbonate, phosphate, sulphate, proteinate ion
Osmosis
movement of water across selectively permeable membrane from an area of HIGH concentration, to area of LOW concentration; based on osmolality
Diffusion
movement of particles across semi-permeable membrane from area of HIGH concentration, to area of LOW concentration
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
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 and Na
Atrial Natriuretic Peptide (ANP) inhibits this system when in state of overload
Hypovolemia
Occurs when loss of ECF volume exceeds the intake of fluid.
decrease in fluid in body
due to: insufficient intake, excessive loss or fluid shifts in body (third spacing)
fluid deficit in intravascular space = difficulty perfusing body, systems activate to raise BP
S&S of Hypovolemia
decreased weight
decreased skin turgor
weak, rapid pulse
low BP
thirst
Confusion
Causes of hypovolemia
vomiting, diarrhea, GI suctioning, sweating, nausea, third spacing shifts
Hypervolemia
retention of fluid in the body (retention of sodium)
due to: excessive intake, abnormal retention (kidney/heart)
fluid overload in intravascular space = raise BP, stress on systems
Hypervolemia causes
heart failure
kidney injury
cirrhosis of the liver
excessive consumption of sodium
S&S of hypervolemia
edema
distended neck veins
dyspnea
cough
Shortness of breath (SOB)
crackles
Fluid Volume Deficit: Nursing Management
- Correct the underlying cause of the deficit (eg. vomiting)
- Replace fluids and electrolytes (oral + IV rehydration)
- Prevent and assess inadequate perfusion
- Signs of improvement:
Stable blood pressure and heart rate
Expected skin turgor
Client moves towards other expected findings
Fluid Volume Overload: Nursing Management
- Correct underlying cause of deficit (eg. heart failure, kidneys)
- Limit sodium/fluid intake
- Administer diuretics
- Signs of improvement:
Daily weight checks
Stable blood pressure
Crackles in lung sounds
Pharmacological interventions for Fluid volume overload
Furosemide (Lasix)
Loop diuretic
Increases renal excretion, mobilizes fluid, decreases BP
Side effects – dizziness, headache, hypotension, electrolyte imbalance
Nursing considerations:
Fall risk
Electrolyte imbalance
Pre-existing kidney function + impact on kidneys
what is the complication associated with fluid volume deficit
hypovolemic shock
what is the complication associated with fluid volume overload?
pulmonary edema, heart failure, impaired gas exchange
Causes of Hypovolemic Shock
hypovolemic = e.g. hemmorage
cardiogenic = e.g. MI
distributive:
Neurogenic = SCI
Anaphylactic
septic = systemic infection
Shock Symptoms
Compensatory
Normal BP
↑ HR
↑ RR
Blood shunting to vital organs
Pale skin
Hypoactive bowel sounds
↓ U/O
Confusion
Progressive
↓ BP
↓ LOC
Irreversible
Severe and permanent organ damage leading to death
Hypovolemic Shock
Cause: Decreased intravascular fluid volume
external fluid losses - fluid is lost externally
internal fluid losses - fluid shifts between intravascular and interstitial compartments (third spacing)
Hypokalemia causes
potassium loss, inadequate intake, movement of K+ from ECF to ICF
Hyperkalemia causes
excessive intake or decreased excretion
S&S Hypokalemia
Decrease GI motility, decrease bowel sounds
Muscle cramps, decreased DTR
Confusion, depression, lethargy
Cardiac: Dysrhythmia, irregular pulse, postural hypotension, cardiac arrest
ECG changes (U wave)
S&S Hyperkalemia
Increase GI motility, Abdominal cramping increase bowel sounds
Muscle twitching, progressing to muscle weakness, flaccid paralysis
Irritability
Cardiac: Bradycardia, hypotension, irregular pulse, cardiac arrest
ECG changes
Hypokalemia Interventions
Supplement K (potassium supplements, increase intake)
IV admin: high alert, need to be administered slowly, NEVER IV push
Falls prevention *muscle weakness
Cardiac monitoring
hyperkalemia Interventions
Administer medications that lower potassium levels and support cardiac health (ex. Kayexalate, calcium gluconate, diuretics, insulin)
Falls prevention
Cardiac monitoring
Sodium
Maintains osmolality as sodium levels determine where water is retained, moved, or excreted
Potassium
Intercellular Electrolyte
Maintains Heart and Muscle Contraction
Hyponatremia causes + results
Actual: Na excretion or decrease Na intake
Relative: fluids dilute
results in - decreased serum osmolality
Hypernatremia causes + results
Actual: increase Na intake or decreased excretion
Relative: fluid loss without Na loss or decrease fluid intake
results in - increased serum osmolality
S&S Hyponatremia
Impacts the Central Nervous System
Behaviour changes, increased ICP, confusion, seizures
Muscle weakness
Increase GI motility, N/V/D, cramping
CV symptoms dependent on fluid status (hypervolemia vs hypovolemia)
S&S Hypernatremia
Impacts CNS
Behaviour changes, seizure
Muscle twitching, cramping, weakness
Thirst, dry mucous membranes
CV symptoms dependent on fluid status (hypervolemia vs hypovolemia)
Hyponatremia Interventions
Administer sodium containing fluids
With normal or excess fluids: Administer medications (diuretic medications that promote water loss, rather than Na loss)
Hypernatremia interventions
Provide health teaching on Na restricted diet
Administer IV infusion: If related to volume loss (hypotonic or isotonic)
Administer medications (Diuretic medications that promote Na loss)
Chloride
Involved in blood pressure and blood volume maintenance and pH balance
Magnesium
involved in neuromuscular contractility
Calcium
Involved in neuromuscular contractility, coagulation and bone health
Phosphate
Bone and Teeth Health, muscle and RBC function, Acid-Base Balance
Clinical significance of Potassium
Essential for cardiac electrical conduction
If too high or too low, rhythm changes can occur in heart and be life threatening
Clinical Significance of Sodium
Sodium moves to area of lesser concentration
High=concentrated=fluid volume loss
Low=diluted=fluid volume overload
Vascular Access Device Selection
Duration: PIV for shorter, CVAD for longer
Patency: PIV more at risk of loss of patency
History of vascular access and comorbidities: difficult prior access, skin, vessels
Type of therapy: vesicant/irritants, pH
Patient’s preference
PIV (peripheral intravenous)
Access in upper extremity
Short term therapy (<7 days)
Monitor for repeated failed/loss access
CVAD (Central venous access devices)
Use when suitable PIV access is unavailable
Long term therapy
Suitable for vesicant/irritant medications/nutrition
Inserted into a large vein in the central circulation system, where the tip of the catheter terminates in the superior vena cava (SVC) that leads to an area just above the right atrium
Inserted by HCP with specialized knowledge
Often inserted with ultrasound guided technique
Common CVADs
Peripherally Inserted Central Catheter (PICC)
Non tunneled CVAD
Tunneled CVAD
Implanted CVAD
PICC
Enters body on upper arm, catheter runs to superior vena cava
VERY common in clinical settings
RNs can insert and remove (specialized skill!)
Medium term use
Non-Tunneled CVAD
Enters body directly at vessel site (internal or external jugular, subclavian, or femoral vein), catheter runs to superior vena cava
Catheter outside of the body at the insertion site
Common in critical care patients (shorter term)
Tunneled CVAD
Tunneled (Hickman or Broviac)
Proximal end tunnelled subcutaneously from the insertion site and brought out through the skin at an exit site.
Antimicrobial cuff
Long term use
Implanted CVAD
Implanted (Port-A-Cath)
Device may be placed in the chest, abdomen, or inner aspect of the forearms
Accessed by special needle (specialized skill!)
Long-term use
What do I need to know about CVADs?
Infections=high risk for sepsis!
Patient populations
PPE
Anti-Microbials
