EXAM 2: F&E Flashcards
What are electrolytes?
substances that dissociate in solution to form a charged particle; electrically charged ions
What are some examples of electrolytes?
K, Na, Cl, Ca, Mg, PO
What are the body fluid compartments?
intracellular: body cells and blood cells have water
extracellular: plasma and interstitial spaces
This occurs when too much fluid moves from the intravascular space (blood vessels) into the interstitial or “third” space:
third spacing (potential space)
Third spacing fluid is:
- trapped in one of the several possible extracellular (transcellular) spaces
- cannot be used for normal function within the body
How do you relieve fluid in third spacing?
letting (cardiocentesis)
What are some examples of third spacing?
- ascites
- pleural effusion
- cardio effusion
This condition results in abdominal fluid build up and is associated with right side heart failure
ascites
This condition results in fluid (bleeding) and air collecting in the pleural space with s/sx such as SOB and cyanosis and can be caused by trauma and cancer:
pleural effusion
What is the normal value for pleural effusion?
4 mL (just enough to separate membranes)
What is edema?
accumulation of excess interstitial fluid in the extracellular space
What is generalized edema referred to as?
anasarca
Where is edema most common?
in the feet and legs
This occurs when edema appears in the face, throat, and eyes:
anaphylaxis
What are the causes of edema?
- increased hydrostatic pressure
- lowered plasma oncotic pressure
- increased capillary permeability
- lymphatic channel obstruction
What is the lowered plasma oncotic pressure due to?
decreased amounts of plasma proteins (albumin)
What reduces the ability to suck fluid from interstitial space back into the capillary?
decreased capillary colloidal osmotic pressure
What causes the solutes to leave the capillary, increase the interstitial osmolality and draw more water in the interstitial spaces (causing edema)?
increased capillary permeability
What kind of obstruction can be caused by cancer or surgery?
lymphatic channel obstruction
What are the functions of body fluids?
- transport gases, nutrients, and wastes
- help generate the electrical activity needed to power body functions
- take part in the transformation of food into energy
- maintain the overall function of the body
What population is at higher risks for function issues?
elderly and babies
Fluid intake can be achieved via:
oral, IV/IM etc.
Fluid outtake can be achieved via:
- sweating
- respiratory
- urinary
- GIT
This consists of fluid contained within all the cells in the body and is the larger of the two compartments:
intracellular compartment (ICF)
The ICF holds how much of the body’s water in healthy adults?
2/3
The ICF has a high concentration of which electrolyte?
K
This contains the remaining 1/3 of body water and contains all the fluids outside the cells (interstitial + tissue spaces + blood vessels)
extracellular compartment (ECF)
The ECF has a high concentration of which electrolyte?
Na
This is pushing force exerted by a fluid:
hydrostatic pressure
This is pulling force of plasma proteins that cannot pass through the capillary membrane:
colloidal osmotic pressure
What does colloidal osmotic pressure assist with?
the movement of fluid back into the capillary
What is the total arterial capillary pressure?
30 mm Hg
What is the total venous capillary pressure?
10 mm Hg
What contributes to outward movement of fluid from the capillary?
interstitial fluid that has a negative hydrostatic pressure of about - 3 mm Hg
The composition of the ECF, plasma, and interstitial fluid consists of:
- large amounts of sodium and chloride (and some bicarbonate)
The composition of intracellular fluids (ICF) consists of:
large amounts of potassium (with some magnesium)
What is the concentration gradient?
the difference in concentration over a distance
This is the movement of charged or uncharged particles along a concentration gradient from an area of higher concentration to one of lower concentration:
diffusion
This is the movement of water across a semipermeable membrane going from a low to high solute concentration:
osmosis
What path does water follow during osmosis?
water goes from the side of the membrane having a lesser number of particles and greater concentration of water TO the side with the greater number of particles and lesser concentration of water
What is osmolarity?
the amount of sodium and other solutes in the blood (majority is sodium)
What is the main source of fluid intake?
water
What is the main source of fluid output?
urine
What mechanisms maintain proper balance?
homeostatic mechanisms
Small amounts of urine results in:
High amounts of urine results in:
highly concentrated urine (too much ADH) diluted urine (too little ADH) > results in thirst
What is the osmolarity of the blood plasma (serum) largely determined by?
the amount of sodium contained in the plasma
A patient with an elevated sodium serum will have hyper-osmolarity. In this case, what fluid movement would you expect to happen?
an increase in plasma sodium (plasma osmolality) attracts water out of the cell, leading to shrinkage of the intracellular volume
This is the tension or effect that the effective osmotic pressure of a solution with impermeable solutes exerts on cell size because of water movement across the cell membrane:
tonicity
In obligatory urine output, how much cc’s are required per 24hours?
300-500 cc’s
An hourly urine output assessment is to:
- increase blood flow by increasing water reabsorption in kidney tubules
- increase systemic vascular resistance - vasoconstriction of blood vessels
How can solutions be classified?
according to whether or not they cause cells to shrink
These cells neither shrink nor swell and there is an equal loss of water and sodium:
isotonic
These cells swell (become lysed) and more Na is lost than water (serum Na is low):
hypotonic
These cells shrink (shrivel) and more water is loss than sodium:
hypertonic
What is the proper term for dehydrated?
fluid volume deficit
Vomiting, diarrhea or misuse of diuretics/lasix’s is an example of what kind of fluid volume deficit?
isotonic
Osmotic diuresis, excessive sweating, loss of thirst and being unable to drink fluids is an example of what kind of fluid volume deficit?
hypertonic
Excess renal losses of Na and aldosterone deficiency is an example of what kind of fluid volume deficit?
hypotonic
What is the recommended treatment for isotonic fluid volume deficit?
IV fluid replacement using NS (0.9%)
Who usually suffers from hypertonic fluid volume deficit due to large glucose molecules drawing out fluids while Na ions are maintaining normal filtration levels
diabetics
What is the recommended treatment for hypertonic fluid volume deficit?
drinking plain water or IV of dextrose 5% in water (D-5-W)
What is the recommended treatment for hypotonic fluid volume deficit?
IV of NS or a 3% solution of Na IV
What are some s/sx of a fluid volume deficit?
- dry skin and mucous membranes (tongue)
- poor skin turgor
- decrease urine output
- babies have a decreased fontanel and their eyes appears sunken
- BP may be decreased with increased HR (orthostatic hypotension)
What are some physiological consequences of fluid volume deficit?
inadequate renal perfusion (blood flow)
What mechanisms protect extracellular fluid volume?
- alterations in hemodynamic variables
2. alterations in sodium and water balance
Alterations in hemodynamic variables results in:
vasoconstriction and an increase in heart rate
Alterations in sodium and water balance results in:
- isotonic contraction or expansion of ECF volume
- hypotonic dilution or hypertonic concentration of extracellular sodium brought about by chances in extracellular water
What are the different types of edema?
- pitting edema (due to extra water, responds well to elevation and diuretics)
- nonpitting edema (caused by factors other than just fluid, making drainage more difficult)
- brawny edema (swelling of subcutaneous tissues that cannot be indented easily by compression)
What physiologic mechanisms contribute to edema?
- increase in capillary filtration pressure
- decrease in capillary colloidal osmotic pressure
- increase in capillary permeability
- obstruction to lymph flow
- localized, general and dependent edema
How can you assess a patient for edema?
- daily weight
- visual assessment
- measurement of the affected part
- application of finger pressure to assess for pitting edema
These physiological mechanisms assist in regulating body water:
>This is primarily a regulator of water intake:
>This is primarily a regulator of water output:
- thirst
- ADH
Both physiological mechanisms respond to changes in:
extracellular osmolarity and volume
What regulates effective volume?
baroreceptors
The rate of sodium is coordinated by the:
- SNS
- angiotensin II
- aldosterone
Water and Na balance modulate:
SNS outflow and ADH secretion