exam 2 module 6

46-80% of their total body weight

an adults total body fluid accounts for

70-80%

what is a newborns total body fluid percentage of total body weight

50-55%

what is total body fluid percentage in a mature woman who is 65 or older

40% or 28L

intracellular fluid is ___ of total body weight

79% or 11 L

interstitial fluid makes up ____ of ECF

21% or 3L

intravascular fluid makes up ___ of ECF

intravascular fluid (plasma) and interstitial fluid

what makes up the ECF

20% or 14L

what is % of total fluid is ECF

potassium, phosphate, magnesium, proteins

in the ICF, there is what

Na-K-ATPase pump

maintains the high concentration of potassium intracellularly

-actively transports sodium ions out and potassium in

3 sodiums for 2 potassiums

what is the exchange in the Na-K-ATPase pump

osmotic pressure

potassium is important for

sodium and chloride

the ECF has a high concentration of

sodium

what part of the ECF is most important for osmotic pressure

ECF

bathes cells in fluid containing proper concentration of electrolytes and nutrients for optimal cell function

interstitial space

a small spacee between tissues and organs

interstitial fluid

the fluid in the space between the tissues

fueling station for cells

function of interstitial fluid

-contains glucose, fatty acids, salt, minerals

¾

how much of extracellular fluid is in the interstitial space

sodium, bicarb, chloride

what elements are prevalent in the interstitial fluid

starling forces

determine the movement of fluid into and out of the circulatory system across the capillary membrane

capillary pressure, plasma colloid osmotic pressure, interstitial fluid pressure, interstitial fluid colloid osmotic pressure

what are the 4 starling forces that are balanced under normal conditions

edema

excessive accumulation of fluid within the interstitial spaces and tissues

-water from intracellular space has moved to extracellular space

third spacing

fluid accumulating in areas where fluid normally doesn’t accumulate

-fluid shifts from intravascular space to interstitial space

all over, localized area

edema is _____ whereas third spacing is in a ____ ____

osmosis

water moving from high to low concentration across semipermeable membrane

-just solvent equilibrates

diffusion

fully permeable membrane where both the solute and solvent equilibrates

osmotic pressure

pressure that must be applied to the side with more solute to prevent a net movement of water across the membrane

osmolality

measure of osmotically active molecules/kg

-not affected by temperature changes or water amount

osmolarity

measure of osmotically active molecules/liter

tonicity

compares the osmolarity of a solution relative to the osmolarity of the plasma

-the ability of a solution to cause water movement into or out of a cell by osmosis

expand

if you infuse a hypotonic solution, the cells will

shrink

if you infuse a hypertonic solution, the cells will

285 mOsm/L

what is the normal concentration the cell

hypotonic

less than 285 mOsm/L

hypertonic

greater than 285 mOsm/L

D5W, 0.45% NaCl

examples of hypotonic solutions

LR, 0.9% NaCl, 5% albumin

examples of isotonic solutions

D5LR, 3% NaCl

examples of hypertonic solutions

3:1 ratio

crystalloid ratio

-for every 1 mL blood loss, 3 mL of crystalloids are administered

1:1 ratio

what is colloid ratio

crystalloids

solution that contains small molecules that can cross the cell membrane

isotonic, hypotonic, hypertonic

3 subgroups of crystalloids

isotonic

have the same concentration of salt as that found in the body

-allows for free movement of water across the membrane without changing thee concentrations of solutes on either side

fluids and electrolytes

crystalloids consist of

lactated ringers

isotonic solution that has the least effect on ECF composition and appears to be most physiologic when large volumes are required

high chloride content

normal saline has a

-can produce dilutional hyperchloremic acidosis

hypotonic solutions

lowers the serum osmolality within the vascular space causing the fluid to shift from intravascular space to both the interstitial and intracellular space

deplete fluid from within the circulatory system

hypotonic solutions hydrate the cells but…

d5w

used to treat free water losses and as maintenance fluid for patients on a sodium restriction as well as neonates and diabetics

hypernatremia, DKA, HHS

what are some conditions that result in intracellular dehydration that you would give hypotonic solutions for

hypertonic solutions

draws water out of intracellular space, increasing extracellular fluid volume

-used in severe hyponatremia

colloid solution

made from plasma donors

-draws fluid from extravascular space utilizing oncontic pressure

intravascular space to expand intravascular volume e

when colloids are infused they remain in the…

albumin

example of a colloid

isotonic

colloids for the most part are

anaphylaxis

what is the most common risk when giving colloids

molecules are large

why do colloids not cross the capillary membrane and just expand intravascular space

resuscitation prior to blood, burns, critically ill fluid bolus

indications for colloids

hypoglycemia, low electrolytes, maintenance fluid

indications for crystalloids

overhydration

what is the risk when giving crystalloids

4 mL/hr for each of the first 10 kg, 2 mL/hr for each of the next 10 kg, 1 mL/hr for every kg after that

4-2-1 rule for fluid maintenance

body weight in kg + 40 cc

what is the shortcut for finding fluid maintenance in adults over 20 kg

preoperative fluid deficit

what do you need to add to maintenance fluid when finding total amount of fluid

maintenance rate * hours NPO

how to find preop fluid deficit

½ deficit over the first hour, ¼ over the second hour, ¼ over the third our

what is the fluid plan for replacing fluid

deficit + maintenance + EBL + 3rd space loss

total fluid to bee administered

1-2 mL/kg/hr

what is the 3rd space loss for superficial surgical trauma

2-4 mL/kg/hr

what is the 3rd space loss for minimal surgical trauma

4-6 mL/kg/hr

what is the 3rd space loss for moderate surgical trauma

6-8 mL/kg/hr

what is the 3rd space loss for high surgical exposure

frank starling curve

cardiac output increases when fluid increases

35-45 nmol/L

what is the normal concentration of H+ in arterial blood and ECF

-log10[H+]

pH=

non volatile acids

metabolic

-eliminated by liver and kidneys

volatile acids

respiratory acids

-eliminated as CO2 gas

buffer systems

these are rapid, within 1-3 minutes, but incomplete

ventilatory and renal response

slower (12-48 hrs) but produce nearly complete correction of pH

-kidneys

bicarbonate, hemoglobin, phosphate, plasma proteins

what are the instantaneous buffers

lungs, ionic shifts, kidneys, bone

what are the organs that take longer when acting as a buffer

ionic shifts as a buffer

exchange intracellular potassium and sodium for hydrogen

lungs as a buffer

regulates retention or elimination of CO2 and therefore H2CO3 concentration

kidneys as a buffer

bicarb reabsorption and regeneration, ammonia formation, phosphate buffering

bone as a buffer

exchanges of calcium and phosphate, release of carbonate

more carbonic acid formed

the greater the PCO2, the …

20:1

what is the ratio of bicarb to carbonic acid when pH is 7.4

protein buffering

serve as buffers for H+

-intracellular buffer

-hemoglobin binds to H+ and becomes a weak acid

respiratory buffering

RR control

-chemoreceptors sense change in pH and PCO2 and adjust RR

kidney buffering

distal tubule secretes H+ into the urine and regenerates bicarb

-phosphate and ammonia bind with H+

cellular ion exchange as a buffer

shifts K for H

-each 10 mmHg decrease in PCO2, K decreases 0.5

respiratory acidosis

increase in blood H+ concentration caused by hypoventilation and CO2 retention

respiratory alkalosis

an decrease in blood H+ concentration caused by hyperventilation and loss of CO2

metabolic acidosis

an increase in blood H+ concentration cause by the addition of acids to, or the loss of bases from body fluids

metabolic alkalosis

decrease in blood H+ concentration caused by the loss of acids from or the addition of bases to body fluids

poisoning, lactic acidosis, renal failure

what are some causes of metabolic acidosis

anion gap

the difference between the negative and positive elements in your blood (such as Na+ and Cl-)

high anion gap

extra acids in your blood

-DKA

pH greater than 7.35 and anion gap greater than 14

what is anion gap acidosis

[Sodium (Na+)] - ([Chloride (Cl-)] + [Bicarbonate (HCO3-)])

anion gap formula

donate protons into solution

strong acids always