Chapter 13 Flashcards
What is the balance of fluid and electrolytes called?
Homeostasis
What is the most common substance in the body?
Water, making up 50%-55% of total body weight.
What is the fluid outside of the cells called?
Extracellular fluid (plasma).
1/3 of total body water
Includes interstitial fluid (third space), blood, lymph, bone, and connective tissue water and transcellular fluids (CSF, synovial fluid, peritoneal fluid, pleural fluid.
What is the fluid inside of the cells called?
Intracellular fluid
2/3 of total body water
What is a solvent?
the WATER portion of fluids
What is a solute?
Particles dissolved or suspended in the water
Solutes that express an overall electrical charge?
Electrolytes
What is filtration?
Movement of fluid through a cell or blood vessel membrane because of hydrostatic pressure differences on both sides of membrane (water volume pressing against confining walls)
What is equilibrium?
Hydrostatic pressure that is the same in both ECF and ICF.
Example of a hydrostatic filtering force.
Blood pressure.
What is diffusion?
Movement of solute from an area of higher concentration to lower concentration (down a concentration gradient)
What is a concentration gradient?
When two fluid spaces have different amounts of the same type of particle.
When is diffusion more rapid?
When the gradient is steeper (when way more particles need to move from higher to lower side)
When can particles NOT move across a cell membrane?
When the membrane is impermeable to the particle.
____cannot cross most cell membranes without the help of insulin. This is due to ________.
Glucose
selective membrane permeability.
Diffusion that requires assistance of membrane-altering system is called
facilitated diffusion or facilitated transport
Movement of water through semipermeable membrane.
Osmosis
Number of mmol/L in a LITER of solution
OsmolaRity (liteR)
number of mmol/L in a KILOGRAM of solution
OsmolaLity (kiLo…also L for little-r amount)
Normal osmolarity value for plasma and other body fluids
270-300 mOsm/L
Fluid with osmolarity >300
Hypertonic or hyperosmotic
Fluid with osmolarity <270
Hypotonic or hypo-osmotic
This mechanism is an example of how osmosis helps maintain homeostasis
Thirst mechanism
Minimum amount of urine to excrete toxic waste products
400-600 mL
Amount of insensible water loss
500-1000mL
Three hormones that help control F&E balance
AldosTYRONE, ADH, and natriuretic peptide
___ is a hormone secreted by the _____ when ___ levels in ECF are decreased
Aldosterone
Adrenal cortex
Sodium
___ or vasopressin, is produced in the brain and stored in the ___. Controlled by the _____ in response to changes in blood osmolarity.
ADH
Posterior pituitary gland.
hypothalamus
___ are hormones secreted by special cells that line the atria of the heart. Are secreted in response to stretching of the heart tissue. Has opposite effect of _____
ANP
aldosterone
___ is secreted by kidneys in response to bring blood pressure back up to normal. Does not allow release of sodium and water.
Renin
A powerful vasoconstrictor that helps elevate blood pressure without adding more blood volume. Also decreases urine output to help elevate blood pressure.
Angiotensin II
Hormone that causes kidneys to reabsorb water and sodium, allowing return to blood, increasing blood pressure and volume
Aldosterone
Best indicator of perfusion adequacy after surgery
Urine output
Most common type of fluid loss problem
Isotonic dehydration
1 L of water weighs
2.2 pounds (1kg)
A weight change of 1 pound corresponds to a fluid volume change of about
500 mL
___is a good indicator of hydration status.
Cardiovascular changes
For every degree (Celsius) increase in body temp, a mimimum of an additional ____ of body fluid is lost.
500mL
Weight loss over ___ is fluid loss
a half pound
Mild to moderate dehydration is corrected with __ and given in a dose of ___ every hour
oral fluid replacement
2-4 ounces
Two most important areas to monitor during rehydration
pulse rate/quality and urine output
Most common type of fluid overload
hypervolemia
Indicators of fluid overload
bounding pulse increasing neck vein distention crackles in lungs increasing peripheral edema reduced urine output Monitor these every 2 hours
Each pound of weight equates to __ of retained water weight.
500mL (1 kg = 1000mL)
Call healthcare provider for weight gain ..
> 3 lbs in a week or 1-2 lbs in 24hr period
Low Na+ inhibits secretion of
ADH and NP, and triggers aldosterone secretion
High Na+ inhibits secretion of
aldosterone, and secretes ADH and NP
Hyponatremia, the osmolarity of ECF is ___ than ICF
lower
Hyponatremia mnemonic
S tupor/coma
A bdominal cramping, N&V
L ethargy
T endon reflexes decreased
L imp muscles (weakness)
O rthostatic hypotension (weak, thready pulse)
S eizures/headache
S tools frequent and watery
Hypernatremia mnemonic
F - Fever (low), flushed skin R - Restless (irritable) I - Increased fluid retention & increased BP E - Edema (peripheral and pitting) D - Decreased urinary output, dry mouth
S - Skin flushed
A - Agitation
L - Low-grade fever
T - Twitching
CAUSE: MODEL Medications, meals Osmotic diuretics Diabetes insipidus Excessive water loss Low water intake
Hyponatremia interventions
D iuretics
I sotonic IV
E at more salt
D rink less
Potassium’s role
MOVIE RATINGS: E, G, PG Excitable tissue depolarization Generates action potential Protein synthesis Glucose use/storage is regulated
What is the main controller of ECF K+ levels?
Sodium-potassium pump
What organ also controls potassium?
Kidney.
Excretion is enhanced by aldosterone
Hypokalemia mnemonic
6 L's (kallllllllemia) Lethargy, aLoc Leg cramps Limp muscles Low, shallow respirations Lethal cardiac dysrhythmias Lots of urine (polyuria) paraLytic iLeus (severe hypokalemia)
Causes of hypokalemia
Drugs (dig, diuretic, corticosteroids) Aldosterone (increased secretion) Cushings Diarrhea Vomiting
Hypokalemia interventions
Drug therapy: K+ replacements
IV is 1 mEq K to 10mL solution. Max infusion rate 5-10 mEq/hr, NEVER exceed 20 mEq!!!
Never give IV push. Will cause cardiac arrest.
Hyperkalemia mnemonic
MURDER M - Motility increased U - Urine, oliguria, anuria R - Respiratory distress D - Decreased cardiac contractility E - ECG changes R - Reflexes, (early: hyperreflexia (twitching), late: areflexia (flaccid)) Causes MACHINE M - Medications - ACE inhibitors, NSAIDS A - Acidosis - Metabolic and respiratory C - Cellular destruction - Burns, traumatic injury H - Hypoaldosteronism/ hemolysis I - Intake - Excessive N - Nephrons, renal failure E - Excretion - Impaired
Hyperkalemia interventions
K- Kayexalate (orally/ enema)
I- Insulin
N- Na HCO3
D- Diuretics (Furosemide & Thiazides)
Potassium movement into the cells is enhanced by __
Insulin
How many charges does Calcium have?
- Divalent cation
How does calcium exist in the body?
bound and ionized (unbound or free form)
What does bound calcium attach to?
serum protein
Where is ionized calcium found?
ECF
What is calcium’s purpose?
Maintaining bone strength and density Activating enzymes Allowing skeletal and cardiac muscle contraction, Controlling nerve impulse transmission Allowing blood clotting
Where is calcium absorbed?
intestinal tract and requires vitamin D for absorbtion
Where is calcium stored?
Bones.
Where is calcium excreted?
Urine
If body needs Calcium, where is serum levels increased?
PTH
What does PTH do to increase Ca++ levels?
Release free Ca++ from bone storage (bone resorption)
Stimulate vitamin D to increase intestinal absorption of Ca++
Inhibit kidney Ca++ excretion
Stimulate kidney Ca++ reabsorption
Hypocalcemia mnemonic
C - Convulsions
A - Arrhythmias
T - Tetany
S - Spasms (charley horses) and stridor
G - Gut (hyperactive bowel sounds)
O -osteoporosis
NUMB (paresthesias)
Baja California
diarrhea (don’t drink water)
dancing (tetany, seizures, Chvostek, Trousseau)
relaxed (decreased HR)
Hypocalcemia interventions
Drug: Ca++ replacement (oral and IV)
Environment: keep room quiet, no overstimulation
Seizure precautions
Hypercalcemia mnemonic
Northern California
Groans: constipation
Moans: pain - joint aches
Bones: loss of calcium from bones, bone metastasis
Stones: kidney stones
Overtones: psychiatric overtones - depression, confusion
Cardiac dysrhythmias
Tissue most affected by hypercalcemia
Heart
skeletal muscles
nerves
intestinal smooth muscle
Hypercalcemia causes faster _____ times
clotting
Clots occur in vessels with slow blood flow
Hypercalcemia intervention
Normal saline IV Lasix Ca++ chelators (binders) Dialysis in severe cases ECG for T-wave changes
Phosphorus in body (P-)
Needed to activate vitamins and enzymes
Forms ATP for energy
Assists in cell growth and metabolism
Phosphorus balance and ____ balance are intertwined
calcium
Meaning change in P- results in equal and opposite change in Ca++
Phosphorus mnemonic
Rhabdo (muscle breakdown)
Cardiac depression
Oddly shaped bones
Hypophosphatemia interventions
D/C antacids, osmotic diuretics, Ca++ supplements
Vitamin D with P- replacement
Increase P- rich foods, decrease Ca++ rich foods
Causes of hyperphosphatemia
kidney disease
certain cancer treatments
increased p- intake
hypoparathyroidism
What is magnesium for?
skeletal muscle contraction carbohydrate metabolism ATP formation vitamin activation cell growth
Daily mg requirement for adults
300mg
Where is Mg++ excreted?
kidneys
Hypomagnesemia effects
Hyperactive deep tendon reflexes parathesias painful muscle contraction Weak muscles Tetany Seizures Depression/confusion/psychosis Abdominal distention
Hypomagnesemia intervention
MgSO4
Assess deep tendon reflex every hour
Hypermagnesmia effects
bradycardia
hypotension
prolonged PR interval with wide QRS complex
absent deep tendon reflex
Chloride is important in formation of
HCl in stomach
___ is anion most commonly exchanged for Cl-
HCO3-
