Fluids Flashcards
Walworth lectures 2,3,4
intracellular fluid percentage of weight
40%
extracellular fluid percentage of weight
20%
interstitial percentage of extracellular
75%
intravascular percentage of extracellular
25%
as age increases, water weight ?
decreases
do males or females have a higher water weight percentage?
males
three major organs of fluid balance
skin
kidney
lungs
what type of fluid loss can be measured?
sensible
what type of fluid loss cannot be measured?
insensible
sensible fluid loss amount per day
1 to 1.5L
insensible fluid loss amount per day
1 L
what of fluid is not subjected to daily gains or losses?
transcellular
isotonic solution mOsm/L
between 275 to 290
hypotonic solution mOsm/L
less than 275
hypertonic solution mOsm/L
greater than 290
what type of hypotonic solutions should not be dispensed?
less than 154 mOsms
what type of hypertonic solutions should be given in small amounts and through a central line?
greater than 600 mOsms
when should NBW be used?
when ABW is 130% of IBW
MIVF requirements
30 to 40 mL per kg per day
what type of solutions are crystalloids and colloids?
crystalloids – all
colloids – always hypertonic
examples of crystalloids
NS
1/2 NS
D5W
LR
Balanced salt solutions
examples of colloids
albuminb (5% or 25%)
Hetastarch
tetrastarch
blood
plasmanate
what do crystalloids provide?
water and/or sodium
what type of fluid is NS?
resuscitation
what type of fluid is 1/2 NS?
maintenance
what type of fluid is lactated ringers?
resuscitation
what does LR approximate?
human plasma
what type of solution is dextrose 5%?
maintenance
is D5w a MIVF by itself?
NO
examples of balanced salt solutions (BSS)
lactated ringers (LR)
normosol-R
plasma-lyte
BSS definition
solutions that contain physiologic levels of chloride and buffer solutions
colloid definition
fluids used to increase plasma oncotic pressure (volume expansion)
albumin
human derived blood product
AE - hypervolemia and azotemia
strengths - 5 and 25%
when should 5% albumin be used?
when the patient needs volume/fluid
when should 25% albumin be used?
when the patient is fluid and/or sodium restricted
SR
number of hydroxyethyl groups per glucose molecule in synthetic colloids
high is greater than 0.5
coagulation
altered at a higher molecular weight in synthetic colloids
high molecular weight
over 200kDa
is high SR and MW good or bad?
Bad
what does the prefix indicate in synthetic colloids, hetastarch, and tetrastarch?
number of hydroxyethyl groups (SR)
1 unit of RBC is equal to how many mL?
230 to 350 mL
low hemoglobin
equal to or greater than 7 to 8 g/dL
how many g/dL is hemoglobin increased by with 1 unit of RBCs?
1 g/dL
what is the most common MIVF?
D5W + 1/2 NS + 20 mEq KCl/L
indications of dehydration and compensate for each other
tachycardia and hypotension
BUN/SCr ratio of dehydration
greater than 20
primarily location of Na+ and K+
Na+ extra cellular
K+ intra cellular
normal Na+ range
135 to 145 mEq/L
what is the most common electrolyte disturbance?
hyponatremia
what can rapid sodium correction cause?
seizure
demyelination
isotonic hyponatremia
hyponatremia with normal osmserum
also called pseudo hyponatremia
caused by increased lipids and proteins, which increases volume and dilutes sodium
calculated Osm is low
hypertonic hyponatremia cause
increased blood glucose
what does high Osmserum but normal calculated osmolality indicate?
presence of other substances in the blood
serum sodiums falls by ____mEq/L for each ___mg/dL increase in BG greater than ___ mg/dL
1.6
100
100
hypovolemic hypotonic hyponatremia
low TBW
very low sodium
isovolemic hypotonic hyponatremia
high TBW
unchanged Na+
hypervolemic hypotonic hyponattremia
very high TBW
high sodium
what is the most type of hyponatremia?
hypotonic
renal causes of hypovolemic hypotonic hyponatremia
diuretics
adrenal insufficiency
salt losing nephropathy
cerebral salt wasting
non-renal causes of hypotonic hyponatremia
blood loss
skin loss
GI loss
what is the urine sodium level from renal causes of hypo-hypo-hypo?
greater than 20 mEq/L
what is the urine sodium level from non-renal causes of hypo-hypo-hypo?
under 20mEq/L
what is the 1 cause of iso-hypo-hypo
SIADH
SIADH
syndrome of inappropriate antidiuretic hormone secretion
water intake exceeds capacity of kidneys to excrete water
#1 cause – drugs
drugs that cause SIADH
antipsychotics
carbamazepine
SSRIs
SIADH treatment
stop taking the medication that is causing it
reduce fluid intake
if reducing water doesn’t work, use vaptan diuretics
symptoms of hypo-hypo-hypo
dehydration
symptom of iso-hypo-hypo
CNS
symptom of hyper-hypo-hypo
edema
max limit of rise in serum sodium
0.5 mEq/L/hr
max limit of rise in sodium
8 to 12 mEq/L/day
treatment of hypo-hypo-hypo
symptomatic - 3% NaCl
asymptomatic - 0.9% NaCl
treatment of iso-hypo-hypo
symptomatic - furosemide or 3% NaCl
asymptomatic - 0.95% NaCl or water restriction
treatment of hyper-hypo-hypo
symptomatic - furosemide, judicious 3% NaCl
asymptomatic - 3% NaCl
symptoms of acute hyponatremia
seizures
brain swelling
how quickly should serum sodium levels be increased?
1 to 2 mEq/L/hr
demyelination
occurs when sodium is added too quickly
reasonable short term Na goal for hyponatremia patients
120 mEq/L
normal K+ range
3.5 to 5 mEq/L
K+
primary intracellular cation
mainly affects the heart
Mg2+ depletion affects reabsorption
symptoms of hypokalemia
weakness
changes in cardiac function
cramping
treatment of hypokalemia
when levels are 3.5 to 4 – none
when levels are 3 to 3.4 – oral potassium for patients with cardiac conditions
when levels are less than 3 – oral potassium in asymptomatic, IV potassium in symptomatic
goal of hypokalemia treatment
correcting Mg depletion
IV K+
should only be used in severe cases of hypokalemia due to the chance of arrhythmia or cardiac arrest if added too quickly
K+ infusion rates
without cardiac monitoring –10mEq/hr
with cardiac monitoring – 20 mEq/hr
with cardiac monitoring EMERGENT – 40 to 60 mEq/hr
normal Mg2+ range
1.5 to 2.5 mEq/L
related to Ca2+ and K+ metabolism
hypomagnesemia
main cause is loop or thiazide diuretics
can be identified by looking for signs of hypocalcemia and hypokalemia
treatment should include treating these disturbances
treatment of asymptomatic hypomagnesemia
Milk of Magnesia 5 to 10ml by mouth QID
Mag-OX 800mg by mouth QD or 400mg by mouth TID with meals
treatment of symptomatic hypomagnesemia with 1 to 2mg/dL level
0.5 mEq/kg via IV
treatment of symptomatic hypomagnesemia with under 1mg/dL level
1 mEq/kg via IV
8 mEq is equal to how many grams?
1 gm
how much magnesium should be infused per hour?
1 gm
normal total calcium levels
8.5 to 10.5 mg/dL
hypocalcemia causes
magnesium deficiency
large volume of blood products
hypoalbuminemia
acute treatment of hypocalcemia
100 to 300mg elemental Ca2+ over 5 to 10 minutes
how would you assess Ca2+ properly?
by using corrected Ca2+ levels
rate of calcium chloride to calcium gluconate to elemental calcium
1 gram to 3 grams to 270 mg
administration rate of calcium
1 gm per hour
normal phosphorus levels
2.5 to 4.5 mg/dL
mild to moderate hypophosphatemia levels
1 to 2 mg/dL
severe hypophosphatemia levels
under 1 mg/dL
treatment of mild to moderate hypophosphatemia
oral PO4
treatment of severe hypophosphatemia
IV PO4
when to use KPhos?
when K+ levels are under 4 mEq/L
when to use NaPhos?
when K+ levels are greater than or equal to 4 mEq/L
