N368 Final Fluids and Electrolytes Flashcards
The most important regulator of fluid is:
thirst
Thirst center is located in:
the hypothalmus
What are the primary regular of fluid output?
kidneys
Mechanisms that influence fluid output
Renin-angiotensin-system
Aldosterone
Antidiuretic hormone
Aldosterone causes the conservation of:
sodium, and excretion of potassium
Increased sodium leads to…
increased water and increased BP
Drugs that interfere with aldosterone production are used as:
antihypertensives
Osmolality
absolute concentration of osmotic solution
Greatest contributor of osmolality is:
sodium
Sodium controlled by the hormone
aldosterone
Tonicity
relative concentration of intravenous fluid
Isotonic IV fluid
No fluid shift
Used to treat fluid loss due to vomit, diarrhea, or surgical procedures, ESPECIALLY WHEN BP IS LOW
Hypertonic IV fluids
Water moves from interstitial space to plasma
What is hypertonic IV fluids used to relieve?
cellular edema, especially cerebral edema
Hypotonic intravenous fluid
Water moves from plasma to interstitial space
Hypotonic is used to treat
dehydration when BP is normal
Fluid deficit can cause
dehydration or shock
Fluid deficit can be treated with
oral or intravenous fluids
Fluid excess can be treated with
diuretics
When replacing fluids and electrolytes you use:
crystalloids and colloids
Causes of water and electrolyte loss:
Volume loss in intravascular space due to lack of fluid volume
Volume loss in intravascular space due to transfer of fluid into third space
Examples of volume loss due to transfer of fluid into third space
kidney failure and liver failure
Examples of volume loss due to lack of fluid volume
NAME?
Treatment of volume loss due to transfer of fluid into third space
Crystalloids as first drug of choice
Treatment of volume loss due to transfer of fluid into third space
Colloids
Colloid helps reduce:
3rd space accumulation, reduces volume loss in intravascular space
How are crystalloids different from colloids?
Crystalloids are capable of leaving plasma and moving to interstitial spaces and intracellular fluid
Types of crystalloids
Isotonic
Hypertonic
Hypotonic
Crystalloids primary use
to replace fluids and promote urine output
What type of crystalloid is used to treat dehydration with LOW BP?
Isotonic solution (ex. normal saline, because the priority is to treat the low BP)
What type crystalloid is used to treat dehydration with NORMAL BP?
Hypotonic solution
What type of crystalloid is used to treat hypernatremia with cellular dehydration?
Hypotonic solution
Colloid molecules
large molecule solutes so they cannot easily cross capillary membrane
Colloid mechanism of action
draw water from intracellular fluid and interstitial spaces into plasma
What do colloids do?
NAME?
Colloid primary use
fluid replacement with hypovolemic shock from hemorrhage, surgery, severe burns
Adverse effects of colloids
Hypersensitivity reactions
Fluid overload
Hypertension
Nursing considerations when using colloids
Monitor fluid volume status
Assess neurological status and urinary output
Teach client to report hypersensitivity or fluid volume overload
Electrolytes are essential to:
nerve conduction, membrane permeability, water balance, and other critical body functions
Major electrolytes
Calcium Magnesium Phosphate Potassium Sodium
What stimulates adrenal gland which releases aldosterone?
Lack of sodium of increase of potassium
What happens when aldosterone increases sodium re absorption?
Increase in potassium excretion so increase in sodium in plasma
What is considered hypernatremia?
Sodium level above 145 mEq/L
What is the most common cause of hypernatremia?
kidney disease
Normovolemic hypernatremia
Caused by excessive sodium intake, no water changes
Hypervolemic hypernatremia
Caused by decreased excretion (ex. kidney disease)
Hypovolemic hypernatremia
Caused by high net-water loss
not enough water intake or excessive water loss due to diarrhea, fever, burns, ect.
Signs and symptoms of hypernatremia
THIRST, fatigue, muscle twitching
Treatment of hypernatremia caused by excessive sodium intake
Low salt diet
Treatment of hypernatremia due to dehydration
hypovolemic hypernatremia
give hypotonic solution
Treatment of hypernatremia due to kidney failure
hypervolemic hypernatremia
give diuretics
What is considered hyponatremia?
Sodium level below 135 mEq/L
Causes of hyponatremia
NAME?
Examples of hyponatremia caused by excessive sodium loss
Vomiting, diarrhea, GI suctioning, diuretic use, sweat
Examples of hyponatremia caused by excessive dilution of plasma
Excessive ADH secretion
Excessive administration of hypotonic IV solution
How does ADH cause concentration of urine
b/c it causes water to be retained into the body, too much ADH can cause fluid retention
Treatment of hyponatremia caused by excessive dilution
loop diuretics to cause isotonic diuresis
Treatment of hyponatremia caused by sodium loss
oral sodium chloride or IV fluids containing salt
- Normal saline
- Lactated ringers
Sodium replacement prototype drug
Sodium chloride
Primary use of sodium replacement (sodium chloride)
to treat hyponatremia when serum level falls below 130 mEq/L
Adverse effects of sodium replacement therapy
hypernatremia and pulmonary edema
Sodium effect vs potassium effect
Sodium effects water, potassium effects muscle (heart)
Potassium effects…
muscle contractility
What is the most abundant intracellular cation?
potassium
Potassium is essential for:
proper nerve functioning and maintaining acid-base balance
How is potassium influenced by aldosterone?
For each sodium ion reabsorbed, one potassium ion is secreted into renal tubules
Fatal imbalances of potassium are usually a result of:
cardiac toxicity
Normal range of potassium
3.5-5 mEq/L
What constitutes hyperkalemia?
Potassium above 5 mEq/L
Causes of hyperkalemia
NAME?
Hyperkalemia due to decreased excretion is usually caused by
renal disease
Hyperkalemia does what to cell excitation?
increases cell excitation
Serious signs/symptoms of hyperkalemia
dysrhythmias and heart block/bradycardia with alternation of ventricular fibrillation and cardiac arrest
Early phase symptoms of hyperkalemia
muscle twitching, fatigue, parasthesias, cramping
Treatment of hyperkalemia
NAME?
How does kayexalate and sorbitol treat hyperkalemia?
Laxatives excrete potassium in stool
How does administering glucose and insulin treat hyperkalemia?
helps move potassium into the cell by activating the potassium sodium pump, potassium going into the cell decreases the serum level
How does administering calcium treat hyperkalemia?
to counter act the potassium toxicity on the heart
What is considered hypokalemia?
Potassium level below 3.5 mEq/L
Hypokalemia is caused by
NAME?
Examples of hypokalemia caused by excessive loss of potassium
NAME?
Signs and symptoms of hypokalemia
NAME?
Treatment of mild hypokalemia
increase dietary intake
Treatment of severe hypokalemia
give oral supplements or parenteral potassium supplements
Nursing consideration when taking oral potassium
take with glass of milk to avoid GI irritation
Potassium replacement therapy prototype drug
potassium chloride
Potassium replacement mechanism of action
electrolyte/potassium supplement
When is potassium replacement therapy contraindicated?
NAME?
Potassium should be closely monitored when used with:
digoxin
High pH is…
alkalosis
pH above 7.45
Low pH is…
acidosis
pH below 7.35
Normal pH
7.35-7.45
Two main buffering systems to help maintain normal pH
Bicarbonate ions and phosphate ions
Carbonic acid
H + HCO3
Acid removal mechanism
CO2 is removed by lungs during exhalation
Acid metabolites are removed by kidney in form of hydrogen ion by excreting urine
How is respiratory acidosis caused by narcotic OD
Narcotic overdose damages brain respiratory center, breathing rate goes down, cant remove enough CO2
Causes of metabolic acidosis
Severe diarrhea Kidney failure: H+ not removed Diabetes Excess alcohol ingestion Starvation
How can diarrhea cause metabolic acidosis
Stool usually has bicarbonate in it, if you lose all bicarbonate you are much more likely to has acidosis
Causes of respiratory alkalosis
Hyperventilation, anxiety, high altitude
How can anxiety cause respiratory alkalosis
Panic attack causes too much loss of CO2 (acid)
Causes of metabolic alkalosis
Constipation
Ingestion of excess sodium bicarb
Severe vomitting
Diuretics causing potassium depletion
How can constipation cause metabolic alkalosis?
Stool usually removes bicarb
How can vomitting cause metabolic alkalosis?
you lose too much acid
Breathing pattern of respiratory alkalosis
INCREASED breathing
Breathing pattern of respiratory acidosis
DECREASED breathing
How do you monitor for acidosis and alkalosis
monitor ABG (arterial blood gas)
Acidosis signs and symptoms
increased HR, arrhythmia, SOB due to rapid deep breathing, coughing, confusion, lethargy, CNS depression, coma
Prototype drug for treating metabolic acidosis
sodium bicarbonate
Sodium bicarbonate mechanism of action
raises pH of body fluids
Primary use of sodium bicarbonate
to correct metabolic acidosis
Adverse effects of sodium bicarbonate
metabolic alkalosis caused by removing too much bicarbonate ion
hypokalemia
Rapid/deep breathing is referred to as:
Kussmaul respiration
Metabolic alkalosis signs and symptoms
slow shallow breathing, nervousness, HYPERactive reflexes, convulsion, dysrhythmias
Prototype drug to treat metabolic alkalosis
ammonium chloride
Ammonium chloride mechanism of action
to decrease pH of body fluids by making more H+ ion
NH4CL -> NH3 + HCL
Primary use of ammonium chloride
to reverse severe metabolic alkalosis
Adverse effect of ammonium chloride
possible acidosis
When is ammonium chloride contraindicated?
In patients with liver failure
When is hypertonic IV solution used?
brain aneurism or swelling of an organ
When is hypotonic solution used
if patient is dehydrated (cells need fluid)
be sure to check BP first
If BP is low you do not want to give what type of solution?
hypotonic
Why do kidney failure patients look puffy?
Because they cannot produce urine
Kidney failure usually leads to metabolic….
acidosis
Normal range of GFR
100-130
What should you do if patient has kidney failure and doctor orders CT scan?
Do not administer CT contrast in pt with GFR of less than 50
Complications of chronic renal failure
HYPERvolemia: fluid imbalance because patients cant make urine, which leads to urine retention
HYPERvolemia: fluid imbalance because patients cant make urine, which leads to urine retention
HYPOcalcemia: patients can’t release calcitrol make by kidneys to absorb calcium
Anemia: kidneys can’t make erythropoietin to stimulate RBC